Patent Application
20240155938
The present invention relates to an organic light emitting compound and an organic light emitting device including the same. More specifically, the present invention relates to a pyrene derivative having a specific structure and a long-lasting and highly efficient organic light emitting device including a light emitting layer employing the pyrene derivative as a host compound.
Organic light emitting devices are self-luminous devices in which electrons injected from an electron injecting electrode (cathode) recombine with holes injected from a hole injecting electrode (anode) in a light emitting layer to form excitons, which emit light while releasing energy. Such organic light emitting devices have the advantages of low driving voltage, high luminance, large viewing angle, and short response time and can be applied to full-color light emitting flat panel displays. Due to these advantages, organic light emitting devices have received attention as next-generation light sources.
The above characteristics of organic light emitting devices are achieved by structural optimization of organic layers of the devices and are supported by stable and efficient materials for the organic layers, such as hole injecting materials, hole transport materials, light emitting materials, electron transport materials, electron injecting materials, and electron blocking materials. However, more research still needs to be done to develop structurally optimized structures of organic layers for organic light emitting devices and stable and efficient materials for organic layers of organic light emitting devices.
Particularly, for maximum efficiency in a light emitting layer, an appropriate combination of energy band gaps of a host and a dopant is required such that holes and electrons migrate to the dopant through stable electrochemical paths to form excitons. Thus, there is a continuing need to develop host and dopant materials.
Accordingly, the present invention is intended to provide a host material having a specific structure that is employed in a light emitting layer of an organic light emitting device. The present invention is also intended to provide a long-lasting and highly efficient organic light emitting device that employs the host material to achieve significantly improved life characteristics and luminous efficiency.
One aspect of the present invention provides a pyrene derivative which is employed as a host compound in an organic layer, preferably a light emitting layer of a device and which is represented by Formula I:
The specific structures of Formula I and Structural Formula 1, definitions of the substituents in Formula I and Structural Formula 1, and specific compounds that can be represented by Formula I and Structural Formula 1 are described below.
The present invention also provides an organic light emitting device including a first electrode, a second electrode opposite to the first electrode, and a light emitting layer interposed between the first and second electrodes wherein the light emitting layer includes the compound represented by Formula I.
The organic light emitting device of the present invention includes a light emitting layer employing the pyrene derivative with a specific structure as a host. The use of the host ensures excellent luminescent properties in terms of lifetime and luminous efficiency, long lifetime, and high efficiency of the device. Due to these advantages, the organic light emitting device of the present invention can find useful applications in not only lighting systems but also a variety of displays, including flat panel displays, flexible displays, and wearable displays.
The present invention will now be described in more detail.
One aspect of the present invention is directed to a compound represented by Formula I:
Specifically, at least one of R1 to R10 is linked to Structural Formula 1.
The compound of Formula I is employed as a host compound in a light emitting layer of an organic light emitting device to achieve long lifetime and high efficiency of the device.
According to one embodiment of the present invention, at least one of R1, R3, R6, and R8 may be linked to the structure represented by Structural Formula 1.
As used herein, the term “substituted” in the definition of the substituents in Formula I and Structural Formula 1 indicates substitution with one or more substituents selected from deuterium, cyano, halogen, hydroxyl, nitro, C1-C24 straight, branched or cyclic alkyl, C3-C24 cycloalkyl, C1-C24 straight, branched or cyclic haloalkyl, C1-C24 alkenyl, C1-C24 alkynyl, C1-C24 heteroalkyl, C1-C24 heterocycloalkyl, C6-C24 aryl, C6-C24 arylalkyl, C2-C24 heteroaryl, C2-C24 heteroarylalkyl, C1-C24 alkoxy, C1-C24 alkylamino, C1-C24 arylamino, C1-C24 heteroarylamino, C1-C24 alkylsilyl, C1-C24 arylsilyl, and C1-C24 aryloxy, or a combination thereof. As used herein, the term “unsubstituted” indicates having no substituent.
In the “substituted or unsubstituted C1-C10 alkyl”, “substituted or unsubstituted C6-C30 aryl”, etc., the number of carbon atoms in the alkyl or aryl group indicates the number of carbon atoms constituting the unsubstituted alkyl or aryl moiety without considering the number of carbon atoms in the substituent(s). For example, a phenyl group substituted with a butyl group at the para-position corresponds to a C6 aryl group substituted with a C4 butyl group.
As used herein, the expression “form a ring with an adjacent substituent” means that the corresponding substituent combines with an adjacent substituent to form a substituted or unsubstituted alicyclic or aromatic ring and the term “adjacent substituent” may mean a substituent on an atom directly attached to an atom substituted with the corresponding substituent, a substituent disposed sterically closest to the corresponding substituent or another substituent on an atom substituted with the corresponding substituent. For example, two substituents substituted at the ortho position of a benzene ring or two substituents on the same carbon in an aliphatic ring may be considered “adjacent” to each other.
The alkyl groups may be straight or branched. The number of carbon atoms in the alkyl groups is not particularly limited but is preferably 1 to 20. Specific examples of the alkyl groups include, but are not limited to, methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methylbutyl, 1-ethylbutyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethylpropyl, 1,1-dimethylpropyl, isohexyl, 2-methylpentyl, 4-methylhexyl, and 5-methylhexyl groups.
The cycloalkyl group is intended to include monocyclic and polycyclic ones and may be optionally substituted with one or more other substituents. As used herein, the term “polycyclic” means that the cycloalkyl group may be directly attached or fused to one or more other cyclic groups. The other cyclic groups may be cycloalkyl groups and other examples thereof include heterocycloalkyl, aryl, and heteroaryl groups. The cycloalkyl group may be specifically a cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl or cyclooctyl group but is not limited thereto.
The heterocycloalkyl group is intended to include monocyclic and polycyclic ones interrupted by a heteroatom such as O, S, Se, N or Si and may be optionally substituted with one or more other substituents. As used herein, the term “polycyclic” means that the heterocycloalkyl group may be directly attached or fused to one or more other cyclic groups. The other cyclic groups may be heterocycloalkyl groups and other examples thereof include cycloalkyl, aryl, and heteroaryl groups.
The aryl groups may be monocyclic or polycyclic ones. Examples of the monocyclic aryl groups include, but are not limited to, phenyl, biphenyl, terphenyl, and stilbenyl groups. Examples of the polycyclic aryl groups include naphthyl, anthracenyl, phenanthrenyl, pyrenyl, perylenyl, tetracenyl, chrysenyl, fluorenyl, acenaphathcenyl, triphenylene, and fluoranthrene groups but the scope of the present invention is not limited thereto.
The heteroaryl groups refer to heterocyclic groups interrupted by one or more heteroatoms. Examples of the heteroaryl groups include, but are not limited to, thiophene, furan, pyrrole, imidazole, triazole, oxazole, oxadiazole, triazole, pyridyl, bipyridyl, pyrimidyl, triazine, triazole, acridyl, pyridazine, pyrazinyl, quinolinyl, quinazoline, quinoxalinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinoline, indole, carbazole, benzoxazole, benzimidazole, benzothiazole, benzocarbazole, benzothiophene, dibenzothiophene, benzofuranyl, dibenzofuranyl, phenanthroline, thiazolyl, isoxazolyl, oxadiazolyl, thiadiazolyl, benzothiazolyl, and phenothiazinyl groups.
The alkoxy group may be specifically a methoxy, ethoxy, propoxy, isobutyloxy, sec-butyloxy, pentyloxy, iso-amyloxy or hexyloxy group but is not limited thereto.
The silyl group is intended to include alkyl-substituted silyl groups and aryl-substituted silyl groups. Specific examples of such silyl groups include trimethylsilyl, triethylsilyl, triphenylsilyl, trimethoxysilyl, dimethoxyphenylsilyl, diphenylmethylsilyl, diphenylvinylsilyl, methylcyclobutylsilyl, and dimethylfurylsilyl.
The amine group may be, for example, —NH2, alkylamine, arylamine or arylheteroarylamine. The arylamine refers to an aryl-substituted amine group, the alkylamine refers to an alkyl-substituted amine group, and the arylheteroarylamine refers to an aryl- and heteroaryl-substituted amine group. The arylamine may be, for example, substituted or unsubstituted monoarylamine, substituted or unsubstituted diarylamine, or substituted or unsubstituted triarylamine. The aryl and/or heteroaryl groups in the arylamine and arylheteroarylamine groups may be monocyclic or polycyclic ones. The arylamine and arylheteroarylamine groups may include two or more aryl and/or heteroaryl groups. In this case, the aryl groups may be monocyclic and/or polycyclic ones and the heteroaryl groups may be monocyclic and/or polycyclic ones. The aryl and/or heteroaryl groups in the arylamine and arylheteroarylamine groups may be selected from those exemplified above.
The aryl groups in the aryloxy and arylthioxy groups are the same as those exemplified above. Specific examples of the aryloxy groups include, but are not limited to, phenoxy, p-tolyloxy, m-tolyloxy, 3,5-dimethylphenoxy, 2,4,6-trimethylphenoxy, p-tert-butylphenoxy, 3-biphenyloxy, 4-biphenyloxy, 1-naphthyloxy, 2-naphthyloxy, 4-methyl-1-naphthyloxy, 5-methyl-2-naphthyloxy, 1-anthryloxy, 2-anthryloxy, 9-anthryloxy, 1-phenanthryloxy, 3-phenanthryloxy, and 9-phenanthryloxy groups. Specific examples of the arylthioxy groups include, but are not limited to, phenylthioxy, 2-methylphenylthioxy, and 4-tert-butylphenylthioxy groups.
The halogen group may be, for example, fluorine, chlorine, bromine or iodine.
According to one embodiment of the present invention, the compound represented by Formula I may be selected from the following compounds 1 to 123:
However, these compounds are not intended to limit the scope of Formula I.
A further aspect of the present invention is directed to an organic light emitting device including a first electrode, a second electrode opposite to the first electrode, and one or more organic layers interposed between the first and second electrodes wherein one of the organic layers, preferably a light emitting layer includes the pyrene derivative represented by Formula I.
According to one embodiment of the present invention, the light emitting layer of the organic light emitting device may further include a dopant compound.
As used herein, the expression “(an organic layer) includes one or more organic compounds” can be interpreted that (the organic layer) includes one of the organic compounds belonging to the scope of the present invention or two or more different compounds belonging to the scope of the organic compounds.
The organic layers of the organic light emitting device according to the present invention may include a hole injecting layer, a hole transport layer, a functional layer having functions of both hole injection and hole transport, a light emitting layer, an electron transport layer, and/or an electron injecting layer.
According to a more preferred embodiment of the present invention, one of the organic layers interposed between the first and second electrodes may be a light emitting layer. The light emitting layer may be composed of a host and a dopant. The light emitting layer may include, as a host, at least one of the compounds that can be represented by Formula I.
The dopant compound used in the light emitting layer may be selected from compounds represented by Formulas D1 to D10:
As used herein, the term “substituted” in the definition of the substituents in Formulas D1 to D10 indicates substitution with one or more substituents selected from the group consisting of deuterium, cyano, halogen, hydroxyl, nitro, C1-C24 alkyl, C3-C24 cycloalkyl, C1-C24 haloalkyl, C2-C24 alkenyl, C2-C24 alkynyl, C3-C24 cycloalkyl, C1-C24 heteroalkyl, C6-C24 aryl, C7-C24 arylalkyl, C7-C24 alkylaryl, C2-C24 heteroaryl, C2-C24 heteroarylalkyl, C1-C24 alkoxy, C1-C24 alkylamino, C12-C24 diarylamino, C2-C24 diheteroarylamino, C7-C24 aryl(heteroaryl)amino, C1-C24 alkylsilyl, C6-C24 arylsilyl, C6-C24 aryloxy, and C6-C24 arylthionyl, more preferably deuterium, cyano, halogen, hydroxyl, nitro, C1-C12 alkyl, C1-C12 haloalkyl, C2-C12 alkenyl, C2-C12 alkynyl, C3-C12 cycloalkyl, C1-C12 heteroalkyl, C6-C18 aryl, C7-C20 arylalkyl, C7-C20 alkylaryl, C2-C18 heteroaryl, C2-C18 heteroarylalkyl, C1-C12 alkoxy, C1-C12 alkylamino, C12-C18 diarylamino, C2-C18 diheteroarylamino, C7-C18 aryl(heteroaryl)amino, C1-C12 alkylsilyl, C6-C18 arylsilyl, C6-C18 aryloxy, and C6-C18 arylthionyl.
In the boron compounds represented by Formulas D3 to D10 as dopant compounds, the aromatic hydrocarbon rings or the aromatic heterocyclic rings T1 to T9 and Q1 to Q3 are optionally substituted with one or more substituents selected from deuterium, C1-C24 alkyl, C6-C24 aryl, C1-C24 alkylamino, and C6-C24 arylamino. Here, the alkyl groups in the C1-C24 alkylamino may be linked to each other and the aryl groups in the C6-C24 arylamino may be linked to each other. The substituents are more preferably C1-C12 alkyl, C6-C18 aryl, C1-C12 alkylamino, and C6-C18 arylamino. Here, the alkyl groups in the C1-C12 alkylamino may be linked to each other and the aryl groups in the C6-C18 alkylamino may be linked to each other.
The compounds represented by Formulas D1 and D2 can be used as dopant compounds in the light emitting layer of the organic light emitting device according to the present invention and specific examples thereof include the following compounds d1 and d239:
The compound represented by Formula D3 can be used as a dopant compound in the light emitting layer and may be selected from the following compounds D101 to D130:
The compounds represented by Formulas D4, D5, and D8 to D10 can be used as dopant compounds in the light emitting layer and may be selected from the following compounds D201 to D476:
The compounds represented by Formulas D6 and D7 can be used as dopant compounds in the light emitting layer and may be selected from the following compounds D501 to D587:
The content of the dopant in the light emitting layer is typically in the range of about 0.01 to about 20 parts by weight, based on about 100 parts by weight of the host but is not limited to this range.
The light emitting layer may further include one or more dopants other than the dopants represented by Formulas D1 to D10 and one or more hosts other than the host represented by Formula I.
The organic layers of the organic light emitting device according to the present invention may form a monolayer structure. Alternatively, the organic layers may be stacked together to form a multilayer structure. For example, the organic layers may have a structure including a hole injecting layer, a hole transport layer, a hole blocking layer, a light emitting layer, an electron blocking layer, an electron transport layer, and an electron injecting layer but are not limited to this structure. The number of the organic layers is not limited and may be increased or decreased. Preferred structures of the organic layers of the organic light emitting device according to the present invention will be explained in more detail in the Examples section that follows.
According to one embodiment of the present invention, the organic electroluminescent device may include a substrate, a first electrode (anode), one or more organic layers, a second electrode (cathode), and a capping layer formed under the first electrode (bottom emission type) or on the second electrode (top emission type).
When the organic electroluminescent device is of a top emission type, light from the light emitting layer is emitted to the cathode and passes through the capping layer (CPL) formed using the compound of the present invention having a relatively high refractive index. The wavelength of the light is amplified in the capping layer, resulting in an increase in luminous efficiency. Also when the organic electroluminescent device is of a bottom emission type, the compound of the present invention can be employed in the capping layer to improve the luminous efficiency of the organic electroluminescent device based on the same principle.
A more detailed description will be given concerning exemplary embodiments of the organic light emitting device according to the present invention.
The organic light emitting device of the present invention includes an anode, a hole transport layer, a light emitting layer, an electron transport layer, and a cathode. The organic light emitting device of the present invention may optionally further include a hole injecting layer between the anode and the hole transport layer and an electron injecting layer between the electron transport layer and the cathode. If necessary, the organic light emitting device of the present invention may further include one or two intermediate layers such as a hole blocking layer or an electron blocking layer. The organic light emitting device of the present invention may further include one or more organic layers such as a capping layer that have various functions depending on the desired characteristics of the device.
A specific structure of the organic light emitting device according to one embodiment of the present invention, a method for fabricating the device, and materials for the organic layers are as follows.
First, an anode material is coated on a substrate to form an anode. The substrate may be any of those used in general organic light emitting devices. The substrate is preferably an organic substrate or a transparent plastic substrate that is excellent in transparency, surface smoothness, ease of handling, and waterproofness. A highly transparent and conductive metal oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2) or zinc oxide (ZnO) is used as the anode material.
A hole injecting material is coated on the anode by vacuum thermal evaporation or spin coating to form a hole injecting layer. Then, a hole transport material is coated on the hole injecting layer by vacuum thermal evaporation or spin coating to form a hole transport layer.
The hole injecting material is not specially limited so long as it is usually used in the art. Specific examples of such materials include 4,4′,4″-tris(2-naphthylphenyl-phenylamino)triphenylamine (2-TNATA), N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine (NPD), N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine (TPD), and N,N′-diphenyl-N,N′-bis(4-(phenyl-m-tolylamino)phenyl)biphenyl-4,4′-diamine (DNTPD).
The hole transport material is not specially limited so long as it is commonly used in the art. Examples of such materials include N,N′-bis(3-methylphenyl)-N,N′-diphenyl-(1,1-biphenyl)-4,4′-diamine (TPD) and N,N′-di(naphthalen-1-yl)-N,N′-diphenylbenzidine (α-NPD).
Subsequently, a hole auxiliary layer and a light emitting layer are sequentially laminated on the hole transport layer. A hole blocking layer may be optionally formed on the light emitting layer by vacuum thermal evaporation or spin coating. The hole blocking layer is formed as a thin film and blocks holes from entering a cathode through the organic light emitting layer. This role of the hole blocking layer prevents the lifetime and efficiency of the device from deteriorating. A material having a very low highest occupied molecular orbital (HOMO) energy level is used for the hole blocking layer. The hole blocking material is not particularly limited so long as it can transport electrons and has a higher ionization potential than the light emitting compound. Representative examples of suitable hole blocking materials include BAlq, BCP, and TPBI.
Examples of materials for the hole blocking layer include, but are not limited to, BAlq, BCP, Bphen, TPBI, NTAZ, BeBq2, OXD-7, and Liq.
An electron transport layer is deposited on the hole blocking layer by vacuum thermal evaporation or spin coating, and an electron injecting layer is formed thereon. A cathode metal is deposited on the electron injecting layer by vacuum thermal evaporation to form a cathode, completing the fabrication of the organic light emitting device.
For example, lithium (Li), magnesium (Mg), aluminum (AI), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In) or magnesium-silver (Mg—Ag) may be used as the metal for the formation of the cathode. The organic light emitting device may be of top emission type. In this case, a transmissive material such as ITO or IZO may be used to form the cathode.
A material for the electron transport layer functions to stably transport electrons injected from the cathode. The electron transport material may be any of those known in the art and examples thereof include, but are not limited to, quinoline derivatives, particularly tris(8-quinolinolate)aluminum (Alq3), TAZ, Balq, beryllium bis(benzoquinolin-10-olate) (Bebq2), ADN, and oxadiazole derivatives such as PBD, BMD, and BND.
Each of the organic layers can be formed by a monomolecular deposition or solution process. According to the monomolecular deposition process, the material for each layer is evaporated into a thin film under heat and vacuum or reduced pressure. According to the solution process, the material for each layer is mixed with a suitable solvent and the mixture is then formed into a thin film by a suitable method such as ink-jet printing, roll-to-roll coating, screen printing, spray coating, dip coating or spin coating.
The organic light emitting device of the present invention can be used in a display or lighting system selected from flat panel displays, flexible displays, monochromatic flat panel lighting systems, white flat panel lighting systems, flexible monochromatic lighting systems, and flexible white lighting systems.
The present invention will be more specifically explained with reference to the following examples. However, it will be obvious to those skilled in the art that these examples are in no way intended to limit the scope of the invention.
100 g (0.447 mol) of 4-bromophenylhydrazine hydrochloride, 107.5 g (0.671 mol) of 3,3-dimethyl-1-indanone, 800 mL of acetic acid, and 30 mL of hydrochloric acid were placed in a round-bottom flask. The mixture was refluxed for 24 h. After completion of the reaction, the reaction solution was cooled to room temperature and poured into 1000 ml of water. The mixture was stirred for 1 h. Thereafter, the reaction mixture was extracted with ethyl acetate and water. The organic layer was concentrated under reduced pressure and purified by column chromatography to afford 80 g (yield 57%) of 1-a.
80 g (0.256 mol) of 1-a, 75.7 g (0.307 mol) of pyrene-1-boronic acid, 5.9 g (0.005 mol) of tetrakis(triphenylphosphine)palladium, 60.2 g (0.436 mol) of potassium carbonate, 560 mL of toluene, 140 mL of ethanol, and 217 mL of water were placed in a round-bottom flask. The mixture was refluxed for 6 h. After completion of the reaction, the reaction solution was cooled to room temperature. The resulting solid was collected by filtration and recrystallized from monochlorobenzene to afford 86 g (yield 77%) of 1-b.
12 g (0.028 mol) of 1-b, 6.8 g (0.033 mol) of iodobenzene, 0.26 g (0.001 mol) of copper iodide, 14.7 g (0.069 mol) of potassium phosphate, 9.5 g (0.083 mol) of 1,2-cyclohexanediamine (cis:trans 50:50), and 120 mL of 1,4-dioxane were placed in a round-bottom flask. The mixture was refluxed for 12 h. After completion of the reaction, the reaction solution was cooled to room temperature and 300 ml of water was poured thereinto. The mixture was stirred for 1 h. Thereafter, the reaction mixture was filtered through Celite. The filtrate was extracted with ethyl acetate and water. The organic layer was concentrated under reduced pressure and purified by column chromatography to give 7.5 g (yield 53%) of 1.
MS (MALDI-TOF): m/z 509.21 [M]+
2 (yield 58%) was synthesized in the same manner as in Synthesis Example 1-3, except that iodobiphenyl was used instead of iodobenzene.
MS (MALDI-TOF): m/z 585.25 [M]+
5 (yield 51%) was synthesized in the same manner as in Synthesis Example 1-3, except that iodobenzene (D5) was used instead of iodobenzene.
MS (MALDI-TOF): m/z 514.25 [M]+
92 (yield 42%) was synthesized in the same manner as in Synthesis Example 1-3, except that 1-bromodibenzofuran was used instead of iodobenzene.
MS (MALDI-TOF): m/z 599.22 [M]+
100 g (0.278 mol) of 1,6-dibromopyrene, 35.3 g (0.278 mol) of phenylboronic acid, 6.4 g (0.006 mol) of tetrakis(triphenylphosphine)palladium (Pd(PPh3)4), 88.3 g (0.833 mol) of sodium carbonate, 1400 mL of toluene, and 420 mL of water were placed in a round-bottom flask that had been purged with nitrogen. The mixture was refluxed for 9 h. After completion of the reaction, the reaction mixture was cooled to room temperature. The resulting solid was collected by filtration and discarded. The filtrate was extracted with ethyl acetate and water. The organic layer was made anhydrous and concentrated under reduced pressure. Column chromatography of the concentrate afforded 46 g (yield 46%) of 5-a.
30 g (0.096 mol) of 1-a, 30.1 g (0.144 mol) of iodobenzene (D5), 0.9 g (0.005 mol) of copper iodide, 51 g (0.240 mol) of potassium phosphate, 32.9 g (0.288 mol) of 1,2-cyclohexanediamine (cis:trans 50:50), and 240 mL of 1,4-dioxane were placed in a round-bottom flask. The mixture was refluxed for 12 h. After completion of the reaction, the reaction solution was cooled to room temperature and filtered through Celite. The filtrate was concentrated under reduced pressure and crystallized from methanol. Thereafter, the resulting solid was collected by filtration and recrystallized from dichloromethane and methanol to afford 26 g (yield 69%) of 5-b.
26 g (0.066 mol) of 5-b, 21.8 g (0.086 mol) of bis(pinacolato)diboron, 1.1 g (0.001 mol) of bis(diphenylphosphino)ferrocene dichloropalladium, 13.0 g (0.132 mol) of calcium acetate, and 260 mL of 1,4-dioxane were placed in a round-bottom flask. The mixture was refluxed for 12 h. After completion of the reaction, the reaction solution was cooled to room temperature and filtered through Celite. The filtrate was concentrated and purified by column chromatography to afford 24 g (yield 82%) of 5-c.
9 g (0.025 mol) of 5-a, 13.1 g (0.030 mol) of 5-c, 0.6 g of tetrakis(triphenylphosphine)palladium, 5.8 g (0.042 mol) of potassium carbonate, 70 mL of toluene, 15 mL of ethanol, and 21 mL of water were placed in a round-bottom flask. The mixture was refluxed for 7 h. After completion of the reaction, the reaction solution was cooled to room temperature and poured into 200 mL of methanol. The precipitated crystal was collected by filtration and recrystallized from toluene/acetone to give 8.3 g (yield 56%) of 38.
MS (MALDI-TOF): m/z 597.32 [M]+
6-a (yield 46%) was synthesized in the same manner as in Synthesis Example 5-1, except that phenylboronic acid (H5) was used instead of phenylboronic acid (D5).
6-b (yield 84%) was synthesized in the same manner as in Synthesis Example 5-2, except that iodobenzene (H5) was used instead of iodobenzene (D5).
6-c (yield 54%) was synthesized in the same manner as in Synthesis Example 5-3, except that 6-b was used instead of 5-b.
37 (yield 53%) was synthesized in the same manner as in Synthesis Example 5-4, except that 6-a and 6-c were used instead of 5-a and 5-c, respectively.
MS (MALDI-TOF): m/z 585.25 [M]+
7-a (yield 43%) was synthesized in the same manner as in Synthesis Example 5-1, except that naphthalen-1-ylboronic acid was used instead of phenylboronic acid (D5).
45 (yield 46%) was synthesized in the same manner as in Synthesis Example 6-4, except that 7-a was used instead of 6-a.
MS (MALDI-TOF): m/z 635.26 [M]+
8-a (yield 44%) was synthesized in the same manner as in Synthesis Example 5-1, except that dibenzofuran-1-ylboronic acid was used instead of phenylboronic acid (D5).
76 (yield 67%) was synthesized in the same manner as in Synthesis Example 6-4, except that 8-a was used instead of 6-a.
MS (MALDI-TOF): m/z 675.26 [M]+
25 g (0.124 mol) of 2-bromonitrobenzene, 24.1 g (0.149 mol) of benzofuran-2-ylboronic acid, 4.3 g (0.004 mol) of tetrakis(triphenylphosphine)palladium, 51.3 g (0.371 mol) of potassium carbonate, 175 mL of toluene, 44 mL of ethanol, and 185 mL of water were placed in a round-bottom flask. The mixture was refluxed for 12 h. After completion of the reaction, the reaction solution was cooled to room temperature, extracted with ethyl acetate and water, concentrated under reduced pressure, and purified by column chromatography to afford 21.6 g (yield 73%) of 9-a.
21.6 g (0.090 mol) of 9-a, 72.9 g (0.271 mol) of triphenylphosphine, and 216 mL of 1,2-dichlorobenzene were placed in a round-bottom flask. The mixture was refluxed for 24 h. After completion of the reaction, the reaction solution was cooled to room temperature and poured into 300 mL of water. The mixture was stirred for 1 h. Thereafter, the reaction mixture was extracted with dichloromethane and water. The organic layer was concentrated under reduced pressure and purified by column chromatography to afford 15 g (yield 80%) of 9-b.
15 g (0.072 mol) of 9-b and 150 mL of dimethylformamide were placed in a round-bottom flask. The mixture was cooled to ≤0° C., and 20.7 g (0.072 mol) of N-bromosuccinimide was divided into 5 portions and added thereto. Thereafter, the reaction solution was heated to room temperature, followed by stirring for 24 h. After completion of the reaction, the reaction solution was poured into 500 mL of water to precipitate a crystal, followed by stirring for 1 h. The crystal was collected by filtration and recrystallized from dichloromethane and methanol to afford 15 g (yield 72%) of 9-c.
18 g (yield 73%) of 9-d was synthesized in the same manner as in Synthesis Example 5-2, except that 9-c and iodobenzene (H5) were used instead of 1-a and iodobenzene (D5), respectively.
14 g (yield 57%) of 9-e was synthesized in the same manner as in Synthesis Example 5-3, except that 9-d was used instead of 5-b.
68 (yield 53%) was synthesized in the same manner as in Synthesis Example 6-4, except that 9-e was used instead of 6-c.
MS (MALDI-TOF): m/z 559.19 [M]+
10-a (yield 76%) was synthesized in the same manner as in Synthesis Example 9-1, except that benzothiophen-2-ylboronic acid was used instead of benzofuran-2-ylboronic acid.
10-b (yield 77%) was synthesized in the same manner as in Synthesis Example 9-2, except that 10-a was used instead of 9-a.
10-c (yield 68%) was synthesized in the same manner as in Synthesis Example 9-3, except that 10-b was used instead of 9-b.
10-d (yield 80%) was synthesized in the same manner as in Synthesis Example 9-4, except that 10-c was used instead of 9-c.
10-e (yield 78%) was synthesized in the same manner as in Synthesis Example 9-5, except that 10-d was used instead of 9-d.
93 (yield 59%) was synthesized in the same manner as in Synthesis Example 6-4, except that 10-e was used instead of 6-c.
MS (MALDI-TOF): m/z 575.17 [M]+
40 g (0.188 mol) of pyrene (D10) and 800 mL of dichloromethane were placed in a 2000 mL reactor under a nitrogen atmosphere. The mixture was stirred. The internal temperature of the reactor was lowered to ≤0° C. and a mixed solution of 58.7 g (0.367 mol) of bromine in 200 mL of dichloromethane was slowly added dropwise. After completion of the dropwise addition, the temperature was raised to room temperature, followed by stirring for 3 h. After completion of the reaction, the reaction solution was added with an aqueous sodium thiosulfate solution. The resulting mixture was stirred for 1 h, followed by filtration. The solid was purified with 1,2-dichlorobenzene to afford 31 g (yield 44.7%) of 11-a.
11-b (yield 45%) was synthesized in the same manner as in Synthesis Example 5-1, except that 11-a was used instead of 1,6-dibromopyrene.
112 (yield 61%) was synthesized in the same manner as in Synthesis Example 5-4, except that 11-b and 9-e were used instead of 5-a and 5-c, respectively.
MS (MALDI-TOF): m/z 572.28 [M]+
ITO glass was patterned to have a light emitting area of 2 mm×2 mm, followed by cleaning. After the cleaned ITO glass was mounted in a vacuum chamber, the base pressure was adjusted to 1×10−7 torr. 2-TNATA (400 Å) and HT (200 Å) were sequentially formed into layers on the ITO. A mixture of the inventive host compound shown in Table 1 and BD as a dopant compound (3 wt %) was formed into a 250 Å thick light emitting layer. Thereafter, the compound represented by Formula E-1 was formed into a 300 Å thick electron transport layer on the light emitting layer. Liq was formed into a 10 Å thick electron injecting layer on the electron transport layer. Al was formed into a 1000 Å thick cathode on the electron injecting layer, completing the fabrication of an organic light emitting device. The luminescent properties of the organic light emitting device were measured at 10 mA/cm2.
Organic light emitting devices were fabricated in the same manner as in Examples 1-11, except that BH1, BH2 or BH3 was used instead of the inventive host compound. The luminescent properties of the organic light emitting devices were measured at 10 mA/cm2. The structures of BH1, BH2, and BH3 are as follow:
BH2
BH3
As can be seen from the results in Table 1, the organic light emitting devices of Examples 1-11, each of which employed the inventive host compound for the light emitting layer, were driven at low voltages and showed high external quantum efficiencies and significantly improved life characteristics compared to the organic light emitting devices of Comparative Examples 1 and 2, each of which employed the compound whose structural features are contrasted with those of the inventive compound, and the organic light emitting device of Comparative Example 3 employing the anthracene derivative widely used in the art. These results concluded that the use of the inventive compounds makes the organic light emitting devices highly efficient and long lasting.
The organic light emitting device of the present invention includes a light emitting layer employing the pyrene derivative with a specific structure as a host. The use of the host ensures excellent luminescent properties in terms of lifetime and luminous efficiency, long lifetime, and high efficiency of the device. Due to these advantages, the organic light emitting device of the present invention can find useful industrial applications in not only lighting systems but also a variety of displays, including flat panel displays, flexible displays, and wearable displays.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0019908 | Feb 2021 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2022/002198 | 2/15/2022 | WO |
