Patent Application
20250143182
The present disclosure relates to a pure organic molecule (dye) of Formula A, free of a metal center, and use thereof as an emitter in organic light-emitting diodes (OLEDs) and other optoelectronic components/devices.
Recently, technologies based on organic light-emitting diodes (OLEDs) have introduced and settled in the field of display technology, and the initial commercial products based on these have emerged. In addition to screen technology, OLEDs are also suitable for flat lighting technology.
These devices are generally implemented as layered structures mainly consisting of organic materials. For better understanding, an example of a simplified structure is illustrated in
Since the first report related to OLEDs (Tang et al. Appl. Phys. Lett. 1987, 51, 913), the above technology has continued to be developed, especially in the field of emitter materials. The first materials based on pure organic molecules can convert up to 25% of excitons into light according to spin statistics, but when phosphorescent compounds are used, the fundamental spin statistics problem can be avoided. Thus, theoretically, all excitons can be converted into light. However, these materials have drawbacks, particularly in terms of cost and stability of materials used.
For triplet emitters suitable for triplet harvesting, transition metal complexes in which a metal is selected from the third-row transition metals are generally used. These are mainly very expensive precious metals such as iridium, platinum, or gold. (With regard to this, see the following: Top. Curr. Chem., 2004, 241, 1, H. Yersin, and Phys. Rev. B 1999, 60, 14422, M. A. Baldo, D. F. O'Brien, M. E. Thompson, S. R. Forrest).
Surprisingly, the above-described drawbacks can be considerably improved or solved by the present disclosure which uses an organic molecule (dye, emitter molecule) of Formula A.
The organic molecule according to the present disclosure includes a central basic unit in the form of a π-system (pi system), i.e., an aromatic (e.g., a heteroaromatic or an aromatic) which is substituted with a functional group having electron donating properties (donor) and a functional group having electron withdrawing properties (acceptor). Both groups are located on adjacent atoms of the central basic unit, i.e., at ortho-position relative to each other. Due to the ortho positioning of these groups (donor and acceptor), these groups have to rotate with respect to each other and thus be orthogonal to each other, resulting in electronic separation from each other. This separation may be understood, for example, by quantum mechanical calculations of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). Therefore, these two frontier orbitals should not overlap or should exhibit only minimal overlap. The π-system of the central basic unit may be mainly part of HOMO or LUMO.
Other than these groups (donor and acceptor), no group electronically affects the π-system (central basic unit). Permitted additional substituents may be alkyl groups or other groups that, for example, have a solubility effect.
The present disclosure provides an organic molecule comprising or consisting of a structure of Formula A which can be used in optoelectronic devices.
In formula A,
(Het)Ar=a conjugated organic group selected from the group consisting of unsubstituted and substituted aromatics, unsubstituted and substituted heteroaromatics, and conjugated double bonds fixed against cis-trans isomerization,
D=a chemically bonded donor group having electron donating properties, and
A=a chemically bonded acceptor group having electron accepting properties, wherein A and D are bonded to directly adjacent atoms of the conjugated organic group (Het)Ar.
In an embodiment of the present disclosure, the organic molecule has a value ΔE(S1−T1) between the lowest excited singlet (S1) state and a triplet (T1) state therebelow of less than 5000 cm−1, less than 3000 cm−1, or less than 2000 cm−1.
In an embodiment of the present disclosure, the organic molecule has an emission lifetime of at most 50 μs, at most 30 μs, or at most 20 μs.
In another embodiment, the organic molecule has both the value ΔE(S1−T1) presented herein and the emission lifetime presented herein.
Examples of donors include aromatics and heteroaromatics that inherently exhibit electron donating properties and/or are substituted with electron donating groups, and other donors directly attached to the central π-system (aromatic or heteroaromatic) (i.e., central basic unit).
Donors may be:
—O(−), an —N(H)-alkyl group, an —N-(alkyl group)2-NH2, —OH, an —O-alkyl group, an —NH(CO)-alkyl group, an —O(CO)-alkyl group, an -alkyl group, a -phenyl group, and/or a —(CH)═C-(alkyl group)2.
Examples of acceptors include aromatics and heteroaromatics that inherently exhibit electron accepting properties and/or are substituted with electron accepting groups, and other donors directly attached to the central π-system (aromatic or heteroaromatic).
Acceptors may be:
Optionally, the organic molecule may have at least one solubilizing group, for example, at least one alkyl group. The solubilizing group increases the solubility of the organic molecule in a given solvent.
In an embodiment, the substituent for increasing solubility (solubilizing group) may be selected from the group consisting of:
In an embodiment of the present disclosure, the organic molecule has a phenyl ring (as illustrated in Formula B) as the central π-system.
In another embodiment of the present disclosure, at least one selected from among the two substituents (i.e., donor and/or acceptor) of the central basic unit includes a heteroatom X, and is bonded to the central basic unit (π-system) via the heteroatom.
The heteroatom X is independently selected from the group consisting of N, S, P, O, and Se.
In another embodiment of the present disclosure, the two substituents (i.e., donor and acceptor) may each independently be bonded to the central basic unit (π-system) via the heteroatom X independently selected from the group consisting of N, S, P, O, and Se.
In another embodiment of the present disclosure, the organic molecule has a structure of Formula C:
Also, the residues R and R1 may optionally lead to or form a fused ring system.
“Oxidized” heteroatom Z(═O)n may be an acceptor (corresponding to A of Formula A or B),
Also, the residues R may optionally lead to or form a fused ring system.
Examples of these acceptors include SO2R, SO2(OR), S(O)R, P(O)RR′, P(O)(OR)(OR′), P(O)R(OR′), SeO2R, and Se(O)R.
In another embodiment of the present disclosure, the organic molecule has a structure of Formula D:
Also, the residue R may optionally lead to or form a fused ring system.
Ar and Ar1 may also be fused with each other or linked to each other via unit E (e.g., carbazole or phenoxazine),
Also, the residue R may optionally lead to or form a fused ring system.
SO2Ar2 is an acceptor (corresponding to A of Formula A or B),
Also, the residue R may optionally lead to or form a fused ring system.
Ar2 may also be fused with other aryl and heteroaryl groups to form a larger aromatic system (e.g., phenyl, naphthyl, anthracenyl, tolyl, or the like).
In another embodiment of the present disclosure, the organic molecule has a structure of Formula E:
Also, the residues R1 to R18 may optionally and independently lead to or form a condensed ring system.
According to another aspect, the present disclosure relates to a method of preparing the above-described organic molecule. In an embodiment, the method comprises the step of substituting at least one selected from among the three groups, i.e., (Het)Ar, A, and/or D (of Formula A or B), with at least one substituent for increasing solubility, wherein the substituent may be selected from the group consisting of:
According to another aspect, the present disclosure relates to use of the organic molecule as described above as an emitter or absorber in an optoelectronic device, and the optoelectronic device may be selected from the group consisting of:
The proportion of the organic molecule as an emitter or an absorber is in a range of 1% to 99% by weight based on a total weight of 100% by weight of a function layer including the organic molecule in the optoelectronic device. In an embodiment of the present disclosure, the proportion of the organic molecule as an emitter or an absorber may be 100% by weight based on a total weight of the function layer.
In an embodiment, the proportion of the organic molecule as an emitter in an optical light-emitting device, particularly OLED, is in a range of 5% to 80% by weight based on a total weight of 100% by weight of a function layer including the organic molecule in the optical light-emitting device.
According to another aspect, the present disclosure relates to an optoelectronic device including the organic molecule as described above. In particular, the optoelectronic device may be selected from the group consisting of organic light-emitting devices, organic diodes, organic solar cells, organic transistors, organic light-emitting diodes, light-emitting electrochemical cells, organic field-effect transistors, and organic lasers.
According to another aspect, the present disclosure relates to a method of producing an optoelectronic device using the organic molecule as described above.
Part of this method may be a step of applying the organic molecule according to the present disclosure to a carrier, and the application may optionally be performed by wet-chemical, by colloidal suspension, or by sublimation.
According to another aspect, the present disclosure relates to a method of modifying the emission and/or absorption properties of an electronic device, the method including a step of introducing the organic molecule according to the present disclosure into a matrix material for conducting electrons or holes in an optoelectronic device.
According to another aspect, the present disclosure relates to use of the organic molecule as described above in an optoelectronic device, and relates to an optoelectronic device for converting (so-called down conversion) UV radiation or blue light into visible light, particularly green light, yellow light, or red light.
The drawings are as follows:
Copper(I) iodide (479 mg, 2.5 mmol) and potassium carbonate (13.8 g, 100 mmol) were placed in a 100 mL two-necked flask with a reflux condenser and evacuated for 5 minutes. Under atmosphere including nitrogen, 50 mL of 2-propanol, 1-fluoro-2-iodobenzene (12.2 g, 55 mmol), thiophenol (5.1 mL, 50 mmol), and ethylene glycol (5.6 mL, 100 mmol) were added. The mixture was stirred at 90° C. for 1 day. The reaction solution was filtered, and the residue was washed with 100 mL of water and 100 mL of EtOAc. After phase separation, the aqueous phase was extracted again with 100 mL of EtOAc. The combined organic phase was washed with a saturated NaCl solution and dried over MgSO4. The solvent was removed under reduced pressure on a rotary evaporator and the residue was filtered through a small amount of silica gel (eluent: CH2Cl2). The solvent was removed again under reduced pressure on a rotary evaporator. 9.8 g of diarylsulfide 1A was obtained as colorless oil that contained approximately 10% 1-fluoro-2-iodobenzene but could react further without further purification.
1H-NMR (500 MHz, CDCl3): δ=7.41-7.37 (m, 2H), 7.37-7.32 (m, 2H), 7.32-7.27 (m, 3H), 7.16-7.08 (m, 2H).
Diarylsulfide 1A (purity 90%, 6.81 g, 30 mmol) was dissolved in 150 mL of glacial acetic acid and treated with 15 mL of H2O2 (30% in water). The mixture was stirred at 100° C. for 2 hours, and then left at room temperature overnight. The reaction solution was poured into 800 mL of water, causing the product to precipitate as a white solid. The solid was filtered and washed with water. The resulting filtrate was dried under vacuum at 50° C. overnight. 5.8 g of diarylsulfone 1B was obtained as a white solid.
1H-NMR (500 MHz, CDCl3): δ=8.11 (td, J=7.5, 1.8 Hz, 1H), 8.05-7.98 (m, 2H), 7.65-7.55 (m, 2H), 7.53 (t, J=7.8 Hz, 2H), 7.32 (t, J=7.7 Hz, 1H), 7.14-7.07 (m, 1H).
3,6-dimethoxycarbazole (696 mg, 3 mmol) was dissolved in 10 mL of dry dimethylformamide (DMF), and NaH (60% in mineral oil, 240 mg, 6 mmol) was added thereto. After stirring for 30 minutes, diarylsulfone 1B dissolved in 10 mL of DMF was added and the mixture was stirred at 100° C. for 2 hours. The reaction solution was poured into 200 mL of ice water. After being left overnight, the solid was filtered and washed with some water. The solid was purified by column chromatography (eluent: CH2Cl2/cyclohexane). 350 mg of product 1 was obtained, which could further be purified by recrystallization from EtOH.
1H-NMR (500 MHz, CDCl3): δ=8.61 (dd, J=7.8, 1.8 Hz, 1H), 7.74 (dtd, J=18.7, 7.5, 1.6 Hz, 2H), 7.44 (d, J=2.5 Hz, 2H), 7.13 (ddt, J=5.5, 4.0, 2.2 Hz, 2H), 7.11-7.07 (m, 2H), 6.88 (t, J=7.9 Hz, 2H), 6.76 (dd, J=8.8, 2.5 Hz, 2H), 6.41 (d, J=8.8 Hz, 2H), 3.92 (s, 6H).
13C-NMR (125 MHz, CDCl3): δ=154.3, 142.7, 139.4, 138.2, 137.1, 135.3, 132.8, 132.8, 130.0, 129.7, 128.4, 127.9, 123.9, 115.0, 111.6, 102.7, 56.3.
4-iodobenzonitrile (11.5 g, 500 mmol), copper(I) iodide (957 mg, 5 mmol), and potassium carbonate (13.8 g, 100 mmol) were placed in a 250 mL two-necked flask with a reflux condenser and evacuated for 5 minutes. Under nitrogen atmosphere, 100 mL of 2-propanol (iPrOH), 1-fluoro-2-thiobenzene (6.41 g, 50 mmol), and ethylene glycol (5.6 mL, 100 mmol) were added. The mixture was stirred at 90° C. for 1 day. The reaction solution was filtered and the residue was washed with 300 mL of EtOAc. The solvent was removed under reduced pressure on a rotary evaporator, and the residue was dissolved in 100 mL of EtOAc and 100 mL of water. The organic phase was washed once more with 100 mL water, followed by washing with 50 mL of a saturated NaCl solution and dried over MgSO4. The solvent was removed under reduced pressure on a rotary evaporator, and the residue was filtered through a small amount of silica gel (eluent: CH2Cl2). The solvent was removed again under reduced pressure on a rotary evaporator. 10.5 g of diarylsulfide 2A was obtained as a white solid, which contains about 5% 4-iodobenzonitrile but can further be converted without further purification.
1H-NMR (500 MHz, CDCl3): δ=7.57-7.43 (m, 4H), 7.25-7.19 (m, 2H), 7.19-7.15 (m, 2H).
Diarylsulfide 2A (purity 95%, 5.31 g, 22 mmol) was dissolved in 150 mL of CH2Cl2. Meta-chloroperbenzoic acid (mCPBA) (70%, 16.3 g, 66 mmol) was added over approximately 10 minutes under ice cooling. Subsequently, the mixture was stirred at room temperature for 16 hours. The reaction solution was washed with 100 mL of a semi-concentrated Na2CO3 solution, and then washed with 50 mL of a saturated NaCl solution and dried over MgSO4. The solvent was removed under reduced pressure on a rotary evaporator and the residue was filtered through a small amount of silica gel (eluent: CH2Cl2). The solvent was removed again under reduced pressure on a rotary evaporator. 5.2 g of diarylsulfone 2B was obtained as a light yellow solid.
1H-NMR (500 MHz, CDCl3): δ=8.17-8.08 (m, 3H), 7.85-7.81 (m, 2H), 7.64 (tdd, J=7.4, 4.9, 1.8 Hz, 1H), 7.37 (t, J=7.7 Hz, 1H), 7.18-7.10 (m, 1H).
Carbazole (2.51 g, 15 mmol) was dissolved in 50 mL of dry DMF, and NaH (60% in mineral oil, 1.20 g, 30 mmol) was added thereto. After stirring for 15 minutes, diarylsulfone 2B dissolved in 50 mL of DMF was added and the mixture was stirred at 100° C. for 2 hours. The reaction solution was poured onto 800 mL of ice. After being left overnight, the solid was filtered and washed with water. The solid was purified by column chromatography (eluent: CH2Cl2). 3.14 g of product 2 was obtained as a white solid.
1H-NMR (500 MHz, CDCl3): δ=8.66-8.61 (m, 1H), 8.03 (d, J=7.7 Hz, 2H), 7.89-7.80 (m, 2H), 7.30-7.23 (m, 5H), 7.19 (ddd, J=8.2, 7.1, 1.2 Hz, 2H), 7.11-7.01 (m, 4H), 6.53 (d, J=8.0 Hz, 2H).
13C-NMR (125 MHz, CDCl3): δ=142.8, 141.9, 141.8, 136.1, 136.0, 133.0, 132.0, 130.3, 130.2, 128.1, 126.1, 123.3, 120.8, 120.1, 117.1, 116.2, 110.4.
| Number | Date | Country | Kind |
|---|---|---|---|
| 22158231.5 | Feb 2022 | EP | regional |
The present application is a U.S. National Phase Patent Application of International Patent Application Number PCT/KR2023/002624, filed on Feb. 23, 2023, which claims priority to and the benefit of European Patent Application Number 22158231.5, filed on Feb. 23, 2022, the entire content of each of which is incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2023/002624 | 2/23/2023 | WO |
