KR102307305B1 - Blue phosphorescent complexes and organic light emitting diode comprising the same - Google Patents

Abstract

The present invention relates to a new blue phosphorescent metal complex and a blue phosphorescent organic light emitting device having improved luminous efficiency and improved stability as well as realization of deep blue through improved color coordinates by employing it as a dopant compound for a light emitting layer. it's about

Description

Blue phosphorescent complexes and organic light emitting diode comprising the same

The present invention relates to a metal complex for a dopant for a light emitting layer and a blue phosphorescent organic light emitting device capable of realizing deep blue through improved color coordinates using the same and having increased luminous efficiency and improved stability.

Organic Light Emitting Device (OLED), which is in the spotlight as a next-generation display, is actively conducting academic research on basic technology and industrial application research based on it in various fields such as electricity, electronics, materials, chemistry, physics, and medicine. is in progress The display applied to high-efficiency, high-performance IT information devices is recognized as a very important technology and is considered as an essential base technology for the 4th industrial revolution as it is the key to realizing immersive images through sensors for biometrics or 3D images in the future. As display technology advances, AM (active matrix) OLED technology is dominating the market by covering all areas of the display front and rear industries such as mobile devices and TVs. OLED-based flexible displays and transparent display areas are already in the initial stage of market formation, and are expected to create great demand in the near future.

In phosphorescent light emission, after electrons are transferred from ground states to excited states, singlet excitons are non-emissions to triplet excitons through inter system crossing. After the transition, the triplet exciton has a mechanism of emitting light while transitioning to the ground state. Such phosphorescence emission cannot directly transition to the ground state during the transition of triplet excitons, so it undergoes a process of transition to the ground state after electron spin inversion has progressed. That is, the luminescence duration of fluorescence is only a few nanoseconds, but in the case of phosphorescence, it corresponds to a relatively long time of several microseconds. In the case of electroluminescence, singlet excitons and triplet excitons are formed in a one-to-three ratio. In general, fluorescent materials have an internal quantum efficiency of only 25%, whereas phosphor materials have up to 100% internal quantum efficiency. Because it can have efficiency, research and development for phosphorescent materials is being actively carried out.

Recently, many efforts have been made to increase the luminous efficiency of phosphorescent organic light emitting diodes (PhOLEDs). As a result, a technique showing high external quantum efficiency of 29% for green and 15% for red has been reported. However, in the case of blue, it is reported that luminous efficiency, color coordinate characteristics, and lifespan are worse than green and red. In order to solve this problem, many studies are currently being conducted, and mainly research on the improvement of the layer structure of the device and new materials of the host and the dopant is being actively conducted. For example, Korean Patent Publication No. 10-2010-0061831 and US Patent Publication No. US20140167001 disclose a technique for a metal complex as a blue phosphorescent dopant. However, when the dopant performance according to the prior art, that is, when a conventional metal complex used as a blue phosphor is applied to the light emitting layer as a dopant, improvement of color coordinates is required, and the efficiency of the dopant is reduced and the non-emission process by excitons easily occurs. There is a problem in that the stability of the Blue phosphorescent dopant is the most necessary material in the display industry that is currently pursued, and there is currently no known material that has secured efficiency and lifespan under conditions of achieving deep blue color coordinates.

Patent Document 1: Republic of Korea Patent Publication No. 10-2013-0034287 (2013. 04. 05.) Patent Document 2: Republic of Korea Patent Publication No. 10-2011-0125932 (2011. 11. 22.) Patent Document 3: United States Patent Publication No. US2014/0167001 (2014. 06. 19.)

Accordingly, an object of the present invention is to provide a metal complex for a dopant for an emission layer capable of improving emission characteristics such as color coordinates, luminous efficiency, and lifespan characteristics of an organic light emitting diode, and a blue phosphorescent organic light emitting diode including the same.

The present invention provides a blue phosphorescent compound represented by the following [Formula A-12] in order to solve the above problems.

[Formula A-12]

A detailed description of the structure of the [Formula A-12] will be described later.

In addition, the present invention is an organic light emitting device comprising a first electrode, a second electrode, and at least one organic material layer disposed between the first electrode and the second electrode, wherein at least one layer of the organic material layer is the blue phosphorescent compound It provides an organic light emitting device, characterized in that it comprises.

According to an embodiment of the present invention, in the organic light emitting device, the blue phosphorescent compound may be included as a dopant compound of the light emitting layer.

The organic light emitting device comprising the metal complex according to the present invention as a dopant compound of the light emitting layer has excellent luminous efficiency, stability and lifespan characteristics of the device by preventing a decrease in the efficiency of the dopant and having durability against non-emission cleavage by excitons. It is possible to implement a deep blue color by color coordinates, so it can be usefully used for various display devices.

1 is an absorption emission spectrum of the fac- or mer- isomer of the B-67 compound according to an embodiment of the present invention.
2 is a cross-sectional view showing the structure of a blue phosphorescent organic light emitting diode (PhOLED) manufactured according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a blue phosphorescent compound capable of implementing deep blue organic light emission, and is characterized by being represented by the following [Formula A-12].

[Formula A-12]

In the above [Formula A-12],

X is O or S, R is an alkyl group having 1 to 7 carbon atoms, Ra and Rb are each independently hydrogen, a halogen group, a cyano group, a substituted or unsubstituted alkyl group having 1 to 7 carbon atoms, a substituted or unsubstituted carbon number It is selected from a 1-7 alkoxy group, a substituted or unsubstituted C1-C7 alkylsilyl group, a substituted or unsubstituted C6-C20 aryl group, and a substituted or unsubstituted C3-C24 heteroaryl group .

In addition, structurally, the blue phosphorescent compound according to the present invention is easily converted from a mer-isomer to a fac-isomer, and the fac-isomer exhibits a much more symmetric structure, thereby further increasing photostability.

On the other hand, in the present invention, the substituted or unsubstituted silver wherein Ra and Rb are a cyano group, a halogen group, an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, an alkylsilyl group having 1 to 7 carbon atoms, and 6 carbon atoms. It means that it is substituted with one or two or more substituents selected from an aryl group having to 24 and a heteroaryl group having 3 to 24 carbon atoms, or substituted with a substituent to which two or more substituents of the substituents are connected, or does not have any substituents.

For specific examples, the substituted aryl group means that a phenyl group, a biphenyl group, a naphthalene group, a fluorenyl group, a pyrenyl group, a phenanthrenyl group, a perylene group, a tetracenyl group, an anthracenyl group, etc. are substituted with other substituents do.

In addition, in the present invention, examples of the substituents will be described in detail below, but the present invention is not limited thereto.

In the present invention, the alkyl group may be linear or branched, and specific examples include a methyl group, an ethyl group, a propyl group, n-propyl group, isopropyl group, butyl group, n-butyl group, isobutyl group, tert-butyl group , sec-butyl group, and the like, but are not limited thereto.

In the present invention, the aryl group may be monocyclic or polycyclic, and examples of the monocyclic aryl group include a phenyl group, a biphenyl group, a terphenyl group, and a stilbene group, and examples of the polycyclic aryl group include a naphthyl group and an anthracenyl group. , a phenanthrenyl group, a pyrenyl group, a perylenyl group, a tetracenyl group, a chrysenyl group, a fluorenyl group, and the like, but the scope of the present invention is not limited to these examples.

In the present invention, the heteroaryl group is a heterocyclic group containing O, N, S or Si as a heteroatom, for example, a thiophene group, a furan group, a pyrrole group, an imidazole group, a thiazole group, an oxazole group, oxadia Zol group, triazole group, pyridyl group, bipyridyl group, pyrimidyl group, triazine group, triazole group, acridyl group, pyridazine group, pyrazinyl group, quinolinyl group, quinazoline group, quinoxalinyl group, phthalazinyl group , pyrido pyrimidinyl group, pyrido pyrazinyl group, pyrazino pyrazinyl group, isoquinoline group, indole group, carbazole group, benzooxazole group, benzoimidazole group, benzothiazole group, benzocarbazole group, benzothiophene group , dibenzothiophene group, benzofuranyl group, dibenzofuranyl group, phenanthroline group, thiazolyl group, isoxazolyl group, oxadiazolyl group, thiadiazolyl group, benzothiazolyl group, phenothiazinyl group, etc. However, the present invention is not limited thereto.

In the present invention, examples of the halogen group include fluorine, chlorine, bromine or iodine.

As described above, the blue phosphorescent compound according to the present invention represented by the [Formula A-12] may be used as an organic material layer of an organic light emitting device due to its structural specificity, and more specifically, it may be used as a dopant in the light emitting layer, Examples include, but are not limited to, the following compounds.

In addition, another aspect of the present invention relates to an organic light emitting device comprising a first electrode, a second electrode, and one or more organic material layers interposed between the first electrode and the second electrode, and specifically, an anode, on the anode It relates to a blue phosphorescent organic light emitting diode including a light emitting layer formed on the light emitting layer and a cathode formed on the light emitting layer.

More specifically, it relates to a blue phosphorescent organic light emitting diode including an anode, a hole transport layer formed on the anode, an emission layer formed on the hole transport layer, an electron transport layer formed on the emission layer, and a cathode formed on the electron transport layer.

That is, the organic light emitting device according to an embodiment of the present invention may have a structure including an anode and a cathode and an organic material layer disposed therebetween, except that the blue phosphorescent compound according to the present invention is used in the organic material layer of the device. can be manufactured using conventional device manufacturing methods and materials.

The organic material layer of the organic light emitting device according to the present invention may have a single-layer structure, but may have a multi-layer structure in which two or more organic material layers are stacked. For example, it may have a structure including a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like. However, the present invention is not limited thereto and may include a smaller number or a larger number of organic material layers.

Accordingly, the organic material layer may include an emission layer, and the emission layer may include the blue phosphorescent compound. Here, the blue phosphorescent compound may be included as a dopant material in the emission layer. When the blue phosphorescent compound is included as a dopant material in the emission layer, the emission layer may further include one or more host compounds. As such, in the present invention, a dopant material may be used in addition to a host for the light emitting layer. When the light emitting layer includes a host and a dopant, the content of the dopant may be generally selected from about 0.01 to about 20 parts by weight based on about 100 parts by weight of the host.

The blue phosphorescent organic light emitting diode according to an embodiment of the present invention is a structural cross-sectional view shown in FIG. 2, and the meanings of each reference numeral are as follows.

10: substrate, 110: transparent positive electrode, 120: HIL, 130: HTL, 140: EML, 150: ETL, 160: negative electrode

A blue phosphorescent organic light emitting diode (PhOLED) according to the present invention is a first electrode functioning as an anode, a light emitting layer (EML) formed on the anode, and a cathode (cathode) formed on the light emitting layer (EML). Includes 2 electrodes. Accordingly, the blue phosphorescent organic light emitting diode may have a multilayer structure.

The blue phosphorescent organic light emitting diode (PhOLED) according to an embodiment of the present invention may further include a hole injection layer (HIL), a hole transport layer (HTL), and a buffer layer (BL). Specifically, the blue phosphorescent organic light emitting diode (PhOLED) according to the present invention includes a first electrode functioning as an anode, a hole injection layer (HIL) formed on the anode, and a hole transport layer (HTL) formed on the hole injection layer. ), a buffer layer (BL) formed on the hole transport layer (HTL), an emission layer (EML) formed on the buffer layer, an electron transport layer (ETL) formed on the emission layer (EML), and a cathode formed on the electron transport layer (ETL) It may include a second electrode functioning as a cathode.

In this case, the light emitting layer (EML) includes the blue phosphorescent compound according to the present invention as described above. In addition, the blue phosphorescent organic light emitting diode (PhOLED) according to the present invention may include a substrate for supporting the layers. The substrate may be provided to support the first electrode. The substrate may include, for example, a glass substrate or a flexible substrate made of a polymer material. Examples of the polymer material included in the flexible substrate may include at least one of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polycarbonate (PC). The first electrode is, for example, indium-tin-oxide (ITO), indium-zinc-oxide (IZO), tungsten oxide (WO), tin oxide (SnO), zinc oxide (ZnO) and zinc-aluminum-oxide (ZAO) metal oxides, such as titanium nitride, etc. metal nitrides, such as gold, platinum, silver, copper, aluminum, nickel, cobalt, lead, molybdenum, tungsten, tantalum, niobium, etc. Metals such as alloys of these metals or alloys of copper iodide And it may be composed of a material selected from conductive polymers such as polyaniline, polythiopine, polypyrrole, polyphenylenevinylene, poly(3-methylthiopine), and polyphenylenesulfide.

The first electrode may be made of, for example, a material having optically transparent properties such as ITO, IZO, and WO.

The hole injection layer (HIL) is disposed between the first electrode and the hole transport layer. The hole injection layer (HIL) is, for example, HAT-CN (1,4,5,8,9,11-hexaazatriphenylene- hexacarbonitrile), [N,N'-bis (naphthalen-1-yl) -N, N′-Bis(phenyl)-benzidine (NPB) and di-[4-(N,N′-ditolyl-amino)-phenyl]cyclohexane (TAPC), 4,4′-bis{N-(1- Naphthyl)-N-phenyl-amino}biphenyl (α-NPD), PEDOT/PSS, copper phthalocyanine (CuPc), 4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine (m- MTDATA), and 4,4′,4″-tris(N-(2-naphthyl)-N-phenyl-amino)-triphenylamine (2-TNATA).

The hole transport layer (HTL) is disposed on the first electrode. The hole transport layer (HTL) is formed of a hole transport material such as N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine (NPB) and di-[4-( N,N′-ditolyl-amino)-phenyl]cyclohexane (TAPC).

The buffer layer BL is disposed on the hole transport layer HTL. The buffer layer BL may be formed of MCBP (9,9',9"-(4,4',4"-(methylsilanetriyl)tris(benzene-4,1-diyl))tris(9H-carbazole)). .

The light emitting layer EML is disposed on the hole transport layer. The emission layer EML may include a host for charge transport and a dopant material for blue phosphorescence. In this case, the dopant may include at least one blue phosphorescent compound implemented according to the present invention as described above.

On the other hand, the host is, for example, 4,4'-bis(carbazol-9-yl)-2,2'-dimethylbiphenyl (CDBP), 4,4'-N,N-dicarbazolebiphenyl (CBP), 1,3-N,N-dicarbazolebenzene (mCP), MCBP(9,9',9''-(4,4',4"-(methylsilanetriyl)tris(benzene-4,1) -diyl))tris (9H-carbazole)) and derivatives thereof can be used.In addition, the host is (4,4'-bis(2,2-diphenyl-ethen-1-yl)diphenyl (DPVBi) , bis(styryl)amine (DSA) type, bis(2-methyl-8-quinolinolato)(triphenylsiloxy)aluminum(III) (SAlq), bis(2-methyl-8-quinolinolato) To) (para-phenolato) aluminum (III) (BAlq), 3- (biphenyl-4-yl) -5- (4-dimethylamino) 4- (4-ethylphenyl) -1,2,4 -Triazole (p-EtTAZ), 3- (4-biphenyl) -4-phenyl-5- (4-tert-butylphenyl) -1,2,4-triazole (TAZ), 2,2' ,7,7'-tetrakis(bi-phenyl-4-yl)-9,9'-spirofluorene (Spiro-DPVBI), tris(para-tertiary-phenyl-4-yl)amine (p-TTA ), 5,5-bis(dimethylboryl)-2,2-bithiophene (BMB-2T) and at least one of perylene.

The electron transport layer (ETL) is disposed on the light emitting layer. The electron transport layer (ETL) may be selected from, for example, an aryl-substituted oxadiazole, an aryl-substituted triazole, an aryl-substituted phenanthroline, a benzocyazole, and a benzciazole compound. For example, 4-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl (BAlq), 1,3-bis(N,Nt-butyl-phenyl)-1,3,4- Oxadiazole (OXD-7), 3-phenyl-4-(1'-naphthyl)-5-phenyl-1,2,4-triazole (TAZ), and tris(8-quinolinato)aluminum ( III) at least one of (Alq3).

The second electrode is disposed on the electron transport layer. The second electrode may be selected, for example, from a metal. The second electrode may include, for example, one or two or more alloys selected from Al, Ca, Mg and Ag. The second electrode may be, for example, Al or an alloy containing Al coated with LiF. In addition, in the present invention, the thickness of each of the layers constituting the blue phosphorescent organic light emitting diode (PhOLED) is not limited. In addition, each of the layers may be formed through the same method as usual, for example, vacuum evaporation such as thermal evaporation, hot air drying after liquid coating, or high temperature firing after coating, depending on each layer, The formation method is not limited.

Hereinafter, the present invention will be described in more detail through Examples and Experimental Examples. These Examples and Experimental Examples are only for specifically illustrating the present invention, and the scope of the present invention is not limited by these Examples and Experimental Examples.

Synthesis example 1: Synthesis of B-67 compound according to the present invention

In order to synthesize the B-67 iridium complex, the ligand was synthesized, and the ligand and the iridium precursor were reacted to synthesize an iridium compound to which three hexacoordinate ligands were bound. In general, the produced iridium compound contains two position fac - and mer - isomers. Each isomer was separated using a silica gel column purification method, and the final compound was obtained as a solid phase with a purity of 98% or more.

(1) Synthesis of Ligand

[Scheme 1-1]

In a reaction vessel, 13.89 g (75.05 mmol) of 2-Bromo-m-xylene was dissolved in 100 mL of the purified solvent Tetrahydrofuran, and the temperature was lowered to -78°C using dry ice and acetone. After checking the temperature, 7.63 mL (82.55 mmol) of n-BuLi was added dropwise and stirred for 30 minutes. After 30 minutes, 100 mL of acetaldehyde was added dropwise and stirred for 1 hour. When the reaction was completed, distilled water was added, extracted using Dichloromethane, and the obtained organic layer was dried over MgSO _{4 ,} and then the solvent was removed under reduced pressure. After dissolving the crude compound in 100 mL of Dichloromethane, 17.8 g (82.39 mmol) of Pyridiniumchlorochromate was added dropwise at room temperature. stirred for 1 hour. Upon completion of the reaction, the reaction product was filtered using a Buchner funnel _{and purified by silica gel column chromatography under a mixed solvent condition of Ethylacetate:Hexane = 1:9 (R f} = 0.55) to obtain 6.59 g of the compound in a yield of 59%. .

¹ H NMR (300 MHz, CDCl ₃ ): 7.15 (t, 1H), 7.02 (d, 2H), 2.47 (s, 3H), 2.25 (s, 6H);

[Scheme 1-2]

_{CuBr 2} was put in a reaction vessel, and it was dissolved in 100 mL of a cleanly purified solvent Ethylacetate and refluxed. To the mixture under reflux, 6.59 g (44.4 mmol) of 1-(2,6-dimethylphenyl)ethanone obtained in [Scheme 1-1] was dissolved in 120 mL of Chloroform, added, and refluxed for 10 hours. After completion of the reaction, the precipitate was filtered using a Buchner funnel, _{and purified by silica gel column chromatography in a mixed solvent condition of Ethylacetate:Hexane = 1:9 (R f} = 0.65) to obtain 7.36 g of the compound in a yield of 73%.

¹ H NMR (300 MHz, CDCl ₃ ): 7.23-7.19 (m, 1H), 7.06-7.04 (m, 2H), 4.28 (s, 2H), 2.26 (s, 6H);

[Scheme 1-3]

7.36 g (32.41 mmol) of 2-Bromo-1-(2,6-dimethylphenyl)ethanone obtained in [Scheme 1-2] was added, dissolved in 50 mL of Formamide, and stirred at 180° C. for 9 hours. When the reaction is complete, the mixture cooled to room temperature is saturated NaHCO ₃ The solution was added to 200 mL and extracted with Ethylacetate. The extracted organic layer was dried over Na ₂ SO _{4 ,} and then the solvent was removed under reduced pressure. Purification by silica gel column chromatography in a solvent condition of ethylacetate (R _f = 0.4) gave 3.24 g of the compound in a yield of 58%.

¹ H NMR (300 MHz, CDCl ₃ ): 8.01 (d, 1H), 7.34 (s, 1H), 7.22 (t, 1H), 7.06 (d, 2H), 2.18 (s, 6H); (N=CH-N peak was not measured.)

[Scheme 1-4]

3.24 g (18.81 mmol) of 5-(2,6-Dimethylphenyl)-1H-imidazole obtained in the above [Scheme 1-3] was added, and 4-Bromodibenzofuran 3.87 g (13.43 mmol) and CuI 0.59 g (2.69 mmol), K _{After adding 3.71 g (26.86 mmol) of 2} CO ₃ , it was dissolved in 60 mL of a purified solvent dimethylformamide and refluxed for 48 hours. After completion of the reaction, the reaction was cooled to room temperature, and the precipitate was filtered using a filter, and then dimethylformamide was removed under reduced pressure, followed by extraction using dichloromethane, distilled water, and aqueous ammonia. The extracted mixture was purified by silica gel column chromatography under a mixed solvent condition of Ethylacetate:Hexane = 1:2 (R _f = 0.5) to obtain 0.6 g (1.77 mmol) of the compound in a yield of 13%.

¹ H NMR (300 MHz, CDCl ₃ ): 9.05 (d, 1H), 8.60 (s, 1H), 8.35 (d, 1H), 8.1-7.3 (m, 8H), 7.23 (t, 1H), 7.15 ( d, 2H), 2.34 (s, 6H); (N=CH-N peak was not measured.)

[Scheme 1-5]

0.6 g (1.77 mmol) of 1-(Dibenzo[b,d]furan-4-yl)-5-(2,6-dimethylphenyl)-1H-imidazole obtained in [Scheme 1-4] was added, and the purified After dissolving in 5 mL of the solvent Tetrahydrofuran, 0.61 mL (10 mmol) of Methyliodide was added to the mixture while stirring, and the mixture was refluxed for 24 hours. When the compound was formed, a solid was generated in the reactant, and when the reaction was completed, the solid was filtered out using a Buchner funnel after cooling to room temperature and washed with Tetrahydrofuran. The solid was dissolved in a small amount of methanol, and diethylether was added to precipitate it, and the precipitate was filtered using a Buchner funnel to obtain 0.62 g (1.29 mmol) of the compound in a yield of 73%.

¹ H NMR (300 MHz, CDCl ₃ ): 11.40 (s, 1H), 8.13 (d, 1H), 8.10 (d, 1H), 8.01 (m, 2H), 7.67-7.46 (m, 4H) 7.41 (t) , 1H), 7.28 (d, 2H), 4.00 (s, 3H), 2.24 (s, 6H);

[Scheme 1-6]

0.62 g of 1-(Dibenzo[b,d]furan-4-yl)-5-(2,6-dimethylphenyl)-3-methyl-1H-imidazol-3-ium iodide obtained in [Scheme 1-5] (1.29 mmol) and Ag ₂ CO ₃ 0.18 g (0.65 mmol), Na ₂ CO ₃ 0.069 g (0.65 mmol), IrCl ₃ 3H ₂ O 0.136 g (0.387 mmol) in 5 mL of purified 2-ethoxyethanol solvent After melting, it was refluxed in a state in which light was blocked using aluminum foil. After the reaction mixture was cooled to room temperature, 50 mL of water was added, and the resulting solution was extracted twice (100 mL×2) using dichloromethane. Then, the dichloromethane solution was washed with 100 mL of saturated aqueous NaCl solution _{, dried over MgSO 4} , and the filtered liquid was evaporated under reduced pressure. After that, it was purified by silica gel column chromatography in a mixed solvent condition of Dichloromethane:hexane = 2:1, and the two isomers of facial (R _f : 0.5, yield: 9 %) and meridional (Rf: 0.6, yield: 23 %) were isolated.

fac -: ¹ H NMR (300.1 MHz, DMSO): 8.25 (s, 3H), 7.84 (d, 3H), 7.48 (d, 6H) 7.40-7.01 (m, 21H), 6.68 (d, 3H) 2.93 ( s, 9H), 2.09 (s, 9H), 1.71 (s, 9H).

mer -: ¹ H NMR (300.1 MHz, DMSO): 8.35 (d, 2H), 8.26 (s, 1H), 7.93 (d, 1H), 7.85 (t, 2H), 7.65-7.59 (m, 4H), 7.42-7.13 (m, 17H), 6.96 (d, 1H), 6.86 (d, 1H), 6,73 (d, 1H), 3.00 (s, 3H), 2.70 (s, 3H), 2.63 (s, 3H), 2.41 (s, 3H), 2.34 (s, 3H), 2.05 (s, 3H), 1.92 (s, 3H), 1.89 (s, 3H), 1.79 (s, 3H).

Mass measured value: [C ₇₂ H ₆₀ IrN ₆ O ₃ ] 1246.83 (facial), 1247.25 (meridional) / Theoretical value: m/z = 1249.44

The purified iridium complex UV-Vis absorption spectrum has absorption at ~350 nm, and λ _max values at ~446 nm and ~452 nm for facial and meridional, respectively.

The absorption emission spectrum of the fac- or mer- isomer of compound B-67 is shown in FIG. 1 below.

Claims (7)

A blue phosphorescent compound represented by the following [Formula A-12]:
[Formula A-12]

In the above [Formula A-12],
X is O or S;
R is an alkyl group having 1 to 7 carbon atoms,
Ra is selected from a halogen group, a cyano group, a substituted or unsubstituted C 1 to C 7 alkyl group, a substituted or unsubstituted C 6 to C 20 aryl group, and a substituted or unsubstituted C 3 to C 24 heteroaryl group is one,
Rb is hydrogen,
a and b are each independently an integer of 1 to 4. According to claim 1,
The substituted or unsubstituted is wherein Ra is a cyano group, a halogen group, an alkyl group having 1 to 7 carbon atoms, an alkoxy group having 1 to 7 carbon atoms, an alkylsilyl group having 1 to 7 carbon atoms, an aryl group having 6 to 24 carbon atoms, and 3 carbon atoms. to 24, which is substituted with one or two or more substituents selected from the heteroaryl group, or substituted with a substituent to which two or more of the substituents are connected, or does not have any substituents. According to claim 1,
The compound represented by the [Formula A-12] is a blue phosphorescent compound, characterized in that any one selected from the following compounds:

An organic light emitting device comprising a first electrode, a second electrode, and one or more organic material layers disposed between the first electrode and the second electrode,
At least one layer of the organic material layer is an organic light emitting device comprising the blue phosphorescent compound according to claim 1 . 5. The method of claim 4,
The organic material layer comprises at least one layer selected from a hole injection layer, a hole transport layer, a layer that simultaneously injects and transports holes, an electron transport layer, a light emitting layer, an electron injection layer, and a layer that simultaneously transports and injects electrons. organic light emitting device. 6. The method of claim 5,
The organic light emitting device, characterized in that the light emitting layer comprises the blue phosphorescent compound. 7. The method of claim 6,
The blue phosphorescent compound is an organic light emitting device, characterized in that used as a dopant compound in the light emitting layer.

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