Thermally activated delayed fluorescent materials based on carbene-gold (I)-arylamine derivatives and preparation methods and applications thereof
By preparing carbene-gold (I)-arylamine derivative thermally activated delayed fluorescence materials, the problems of low internal quantum efficiency, high cost and long life of traditional OLEDs were solved, and high-efficiency, low-cost full-color OLED applications were realized.
Patent Information
- Application Number
- CN202310557779.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-05-17
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2043-05-17
AI Technical Summary
In existing technologies, the upper limit of the internal quantum efficiency of traditional fluorescent OLEDs is 25%. Precious metal phosphorescent complexes are expensive and cause serious environmental pollution. The lifespan of pure organic thermally activated delayed fluorescent materials is too long, resulting in device efficiency roll-off. Carbene-metal-arylamine derivative materials are difficult to synthesize and their types are limited.
Carbene-gold (I)-arylamine derivatives are used as thermally activated delayed fluorescent materials. By adjusting the electron donating ability of the donor and combining the heavy atom effect of the gold atom, the preparation method includes carrying out a nucleophilic substitution reaction under anhydrous and oxygen-free conditions, using an organic base as a catalyst, and the purification steps include recrystallization and sublimation.
It realizes efficient thermally activated delayed fluorescent materials with a lifetime of less than 1μs, reduces the efficiency roll-off of the device, can adjust the light color to achieve full-color OLED, and reduces the cost of using precious metals.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the field of organic photoelectric material preparation and electroluminescent devices. More specifically, the present invention relates to a full-color thermally activated delayed fluorescent material based on carbene-gold (I)-arylamine derivatives, and a preparation method and application thereof. Background Art
[0002] Since Dr. Qingyun Deng first applied the fluorescent metal complex 8-hydroxyquinoline aluminum to organic electroluminescence in 1987, organic light-emitting diodes (OLEDs) have garnered widespread attention from both academia and industry. However, due to limitations in their fluorescence properties, the internal quantum efficiency of conventional fluorescent OLEDs is capped at 25%. To achieve 100% internal quantum efficiency, phosphorescent complexes of heavy metals such as Ru(II), Ir(III), Os(II), and Pt(II) have emerged. In particular, Ir(III) complexes are widely used in the OLED industry due to their high luminous efficiency and stability. However, the abundance of precious metals on Earth is extremely low, and their high cost and potential environmental pollution are detrimental to sustainable development. Currently, thermally activated delayed fluorescence (TADF) materials have emerged as a promising class of materials with potential practical applications in OLEDs. Most TADF materials reported to date are organic compounds with a small SOC between the S1 and T1 states, resulting in relatively long delayed fluorescence lifetimes (typically >5μs), which severely reduces device efficiency at high brightness. So far, the types of metal complexes with TADF properties are still very limited.
[0003] Compared with the above-mentioned noble metals, gold has a relatively high abundance in the earth's crust. In addition, compared with metals such as copper and silver, the coordination bonds formed by gold have higher stability, making it an attractive candidate material for the development of OLEDs. However, Au(III) complexes have a small metal contribution and often show ligand-centered emission. Their low radiative decay rate and long lifetime lead to severe efficiency roll-off in OLEDs, and only a few devices can achieve both good EQE and low efficiency roll-off. Recently, carbene-metal-arylamine derivatives with a di-coordinated structure have attracted widespread attention due to their efficient TADF and sub-microsecond delayed lifetime, but the material synthesis is relatively difficult and the types need to be further developed. Summary of the Invention
[0004] In view of the shortcomings of the existing technology and the need to expand the types of existing carbene-metal-arylamine derivatives, the problems of long lifetime, severe device efficiency roll-off, and high cost of phosphorescent heavy metal complexes in pure organic thermally activated delayed fluorescent materials are addressed. The present invention provides a thermally activated delayed fluorescent material of a carbene-gold(I)-arylamine derivative, as well as its preparation method and application.
[0005] The technical solutions of the present invention are as follows:
[0006] The present invention provides a thermally activated delayed fluorescence material based on a carbene-gold (I)-arylamine derivative, the general structural formula of which is shown in Formulas A and B:
[0007]
[0008] Wherein R is a protecting group which can be selected from but not limited to one of the following structures:
[0009]
[0010] The number of R1-R8 is at least one, or a combination of different numbers, R1-R8 are the same or different, and are independently selected from hydrogen, halogen, trifluoromethyl, cyano, C1-C4 alkyl, C1-C6 alkoxy, substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted C3-C 30 heteroaryl;
[0011] Or adjacent two of R1-R8 are connected to each other to form C6-C 30 Aryl, C5-C 30 of heteroaryl.
[0012] The substituted C6-C 30 Aryl, substituted C5-C 30 The heteroaryl group contains 1-8 substituents, and the substituents are independently selected from hydrogen, halogen, cyano, C1-C4 alkyl, C6-C 30 Aryl, C5-C 30 any one of a heteroaryl group, a substituted or unsubstituted diarylamino group.
[0013] By adjusting the electron-donating ability of the donor, emission from blue to red light can be achieved.
[0014] The above compound has the following specific structure:
[0015]
[0016]
[0017]
[0018]
[0019]
[0020]
[0021] The present invention provides a method for preparing a thermally activated delayed fluorescent material based on a carbene-gold (I)-arylamine derivative. The synthetic route is as follows:
[0022]
[0023] The preparation method comprises the steps of:
[0024] Under anhydrous and oxygen-free conditions, a carbene complex intermediate, an aromatic amine derivative, and a base are added to an aprotic organic solvent for reaction. After purification, a thermally activated delayed fluorescent material based on a carbene-gold (I)-arylamine derivative is obtained.
[0025] The base used is an organic base or an inorganic base such as sodium hydride, potassium hydride, sodium tert-butoxide, potassium tert-butoxide, potassium carbonate, cesium carbonate, etc.
[0026] Preferably:
[0027] The base used was sodium hydride.
[0028] The nucleophilic substitution reaction is carried out at room temperature, and the reaction time is 0.5-48 hours.
[0029] Preferably:
[0030] The reaction time is 2h.
[0031] The nucleophilic substitution reaction is carried out in tetrahydrofuran, 1,4-dioxane, acetone or other polar aprotic solvents.
[0032] Preferably:
[0033] The selected solvents are tetrahydrofuran and acetone.
[0034] The purification steps selected include recrystallization and sublimation.
[0035] The present invention also provides an application of an organic thermally activated delayed fluorescent material based on a carbene-gold (I)-arylamine derivative in the preparation of an organic electroluminescent device.
[0036] Preferably:
[0037] Used as a luminescent material in electroluminescent devices.
[0038] The present invention also provides an organic electroluminescent device, wherein the light-emitting layer of the organic electroluminescent device comprises the above-mentioned thermally activated delayed fluorescent material based on carbene-gold (I)-arylamine derivatives.
[0039] The present invention has the following advantages:
[0040] (1) Aromatic amine derivatives with strong electron-donating properties are used as electron donors, and carbenes with π-electron-withdrawing properties are used as electron acceptors. The excited state of the complex has significant LLCT characteristics, which makes it easy to obtain high-efficiency TADF.
[0041] (2) The light color can be adjusted by using aromatic amine derivatives with different electron-donating abilities, thereby achieving high-efficiency OLEDs with a full color range.
[0042] (3) The heavy atom effect provided by gold atoms can significantly increase the reverse intersystem crossing rate, making the lifetime of the complex less than 1μs, which is beneficial to reducing the accumulation of triplet excitons. When applied to devices, it can reduce the device efficiency roll-off. BRIEF DESCRIPTION OF THE DRAWINGS
[0043] Figure 1 This is the UV-visible absorption spectrum of the TADF fluorescent material 27 of the present invention in toluene solution.
[0044] Figure 2 This is the fluorescence spectrum of the TADF fluorescent material 27 of the present invention in toluene solution.
[0045] Figure 3 This is a fluorescence spectrum diagram of the TADF fluorescent material 27 of the present invention doped with 10% in the host material mCP.
[0046] Figure 4 This is a transient photoinduced spectrum decay curve of the TADF fluorescent material 27 of the present invention in a toluene solution.
[0047] Figure 5 This is a transient photoinduced spectrum decay curve of the TADF fluorescent material 27 of the present invention doped with 10% in the host material mCP.
[0048] Figure 6 It is a schematic structural diagram of the spin-coated organic electroluminescent device of the present invention. DETAILED DESCRIPTION
[0049] The present invention provides a thermally activated delayed fluorescent material based on a carbene-gold(I)-arylamine derivative, a preparation method thereof, and its application in an electroluminescent device. To clarify and define the objectives, technical solutions, and effects of the present invention, the following examples further illustrate the technical solutions of the present invention. It should be understood that the specific examples described herein are merely illustrative of the present invention and are not intended to limit the present invention.
[0050] The raw materials and reagents used in the present invention can all be obtained from commercial sources.
[0051] The following is a detailed description through specific embodiments.
[0052] Example 1: Preparation of several important intermediates
[0053] Preparation of intermediate 1
[0054] The synthetic route is:
[0055]
[0056] Dissolve 9-anthracenecarboxaldehyde (20 mmol, 4.1 g) and 2-methyl-3-butyn-2-amine (30 mmol, 2.5 g) in 100 mL of toluene and reflux for 24 hours. Cool to room temperature, remove toluene by vacuum distillation, and purify by column chromatography to obtain 2.6 g of a light yellow solid (48% yield).
[0057] Preparation of intermediate 2
[0058] The synthetic route is:
[0059]
[0060] Intermediate 1 (5.4 g, 20 mmol), 1-bromoadamantane (4.7 g, 22 mmol), 2,6-di-tert-butyl-4-methylpyridine (0.4 g, 2 mmol), and silver trifluoromethanesulfonate (6.2 g, 24 mmol) were placed in a 250 mL round-bottom flask. 100 mL of n-hexane was added and the mixture was allowed to react at room temperature in the dark for 24 h. Upon completion of the reaction, the n-hexane was removed by vortexing, and the product was dissolved in dichloromethane. The filtrate was vortexed to a minimum and recrystallized from n-hexane. The product precipitated, filtered, and dried to obtain 4.0 g of a white solid in a 37% yield.
[0061] Preparation of intermediate 3
[0062] The synthetic route is:
[0063]
[0064] Intermediate 2 (2.2 g, 4 mmol) and (dimethyl sulfide) gold (I) chloride (1.18 g, 4 mmol) were dissolved in 20 mL of ultra-dry tetrahydrofuran and cooled at 0°C for 5 minutes. Potassium bis(trimethylsilyl)amide (1 mol / L in THF, 8 mL) was then added and the mixture was reacted at 0°C overnight. The mixture was recrystallized from tetrahydrofuran / n-hexane to give 382 mg of a light yellow-green solid with a yield of 15%.
[0065] Preparation of intermediate 4
[0066] The synthetic route is:
[0067]
[0068] Intermediate 1 (2.7 g, 10 mmol) was placed in a 100 mL pressure tube and dissolved in 30 mL of acetonitrile. 2-Bromopropane (6.2 g, 50 mmol) was then added and reacted at 90°C for 48 hours. After the reaction was complete, the mixture was cooled to room temperature, the solvent was vortexed to a minimum, and ether was added to precipitate the product. The product was filtered and dried to obtain 2.4 g of a white solid with a yield of 62%.
[0069] Preparation of intermediate 5
[0070] The synthetic route is:
[0071]
[0072] Intermediate 4 (1.977 g, 5 mmol) and (dimethyl sulfide)gold(I) chloride (1.48 g, 5 mmol) were dissolved in 20 mL of ultra-dry tetrahydrofuran and cooled at 0°C for 5 minutes. Potassium bis(trimethylsilyl)amide (1 mol / L in THF, 10 mL) was then added and the mixture was reacted at 0°C overnight. The mixture was recrystallized from tetrahydrofuran / n-hexane to give 464 mg of a light yellow-green solid with a yield of 17%.
[0073] Preparation of intermediate 6
[0074] The synthetic route is:
[0075]
[0076] 3-Bromocarbazole (1.2 g, 5 mmol) and cuprous cyanide (448 mg, 5 mmol) were dissolved in 10 mL of N-methylpyrrolidone under argon protection and reacted at 170°C overnight. After the reaction was completed, the mixture was cooled to room temperature and iron (III) chloride hydrochloric acid solution was added to the system to dispose of the remaining cuprous cyanide. The mixture was washed with water, extracted with chloroform, and purified by column chromatography to obtain 0.7 g of a white solid with a yield of 72%.
[0077] Example 2:
[0078] Synthesis of compound 2
[0079] The synthetic route is:
[0080]
[0081] Intermediate 6 (192 mg, 1 mmol) synthesized in Example 1 was dissolved in 5 mL of ultra-dry tetrahydrofuran (sodium cyanide (60% dispersion in mineral oil, 60 mg, 1.5 mmol)) and reacted at room temperature for 5 minutes. Separately, intermediate 3 (638 mg, 1 mmol) synthesized in Example 1 was dissolved in 5 mL of ultra-dry tetrahydrofuran and reacted at room temperature for 2 hours. After the reaction, the mixture was filtered through celite and recrystallized from dichloromethane / n-hexane to obtain 492 mg of the product with a yield of 62%. HRMS (ESI) m / z calculated for C 43 H 39 AuN3 + (M) + 794.28040,found 794.28011.
[0082] Example 3:
[0083] Synthesis of compound 1
[0084] The synthetic route is:
[0085]
[0086] Carbazole (167 mg, 1 mmol) and sodium cyanide (60% dispersion in mineral oil, 60 mg, 1.5 mmol) were dissolved in 5 mL of ultra-dry tetrahydrofuran and reacted at room temperature for 5 minutes. Intermediate 3 (638 mg, 1 mmol) synthesized in Example 1 was dissolved in 5 mL of ultra-dry tetrahydrofuran and reacted at room temperature for 5 hours. After the reaction, the mixture was filtered through celite and recrystallized from dichloromethane / n-hexane to obtain 422 mg of the product with a yield of 55%. HRMS (ESI) m / z calculated for C 43 H 39 AuN3 + (M) + 769.28525, found 769.28502.
[0087] Example 4:
[0088] Synthesis of compound 27
[0089] The synthetic route is:
[0090]
[0091] 3,6-di-tert-butylcarbazole (279 mg, 1 mmol) and sodium cyanide (60% dispersion in mineral oil, 60 mg, 1.5 mmol) were dissolved in 5 mL of ultra-dry tetrahydrofuran and reacted at room temperature for 5 minutes. Separately, intermediate 3 (638 mg, 1 mmol) synthesized in Example 1 was dissolved in 5 mL of ultra-dry tetrahydrofuran and reacted at room temperature for 5 hours. After the reaction, the mixture was filtered through celite and recrystallized from dichloromethane / n-hexane to obtain 616 mg of the product with a yield of 70%. HRMS (ESI) m / z calculated for C 43 H 39 AuN3 + (M) + 881.41035, found 881.41022.
[0092] Example 5:
[0093] Synthesis of compound 35
[0094] The synthetic route is:
[0095]
[0096] Carbazole (167 mg, 1 mmol) and sodium cyanide (60 mg, 1.5 mmol, 60% dispersion in mineral oil) were dissolved in 5 mL of ultra-dry tetrahydrofuran and reacted at room temperature for 5 minutes. Intermediate 5 (545 mg, 1 mmol) synthesized in Example 1 was dissolved in 5 mL of ultra-dry tetrahydrofuran and reacted at room temperature for 5 hours. After the reaction, the mixture was filtered through celite and recrystallized from dichloromethane / n-hexane to obtain 291 mg of the product with a yield of 43%. HRMS (ESI) m / z calculated for C 43 H 39 AuN3 + (M) + 677.22255, found 677.22213.
[0097] Example 6:
[0098] Synthesis of compound 61
[0099] The synthetic route is:
[0100]
[0101] 3,6-di-tert-butylcarbazole (279 mg, 1 mmol) and sodium cyanide (60% dispersion in mineral oil, 60 mg, 1.5 mmol) were dissolved in 5 mL of ultra-dry tetrahydrofuran and reacted at room temperature for 5 minutes. Intermediate 3 (545 mg, 1 mmol) synthesized in Example 1 was dissolved in 5 mL of ultra-dry tetrahydrofuran and reacted at room temperature for 5 hours. After the reaction, the mixture was filtered through celite and recrystallized from dichloromethane / n-hexane to obtain 457 mg of the product with a yield of 58%. HRMS (ESI) m / z calculated for C 43 H 39 AuN3 + (M) + 789.34775, found 789.34742.
[0102] Test Example 1:
[0103] UV-visible absorption spectrum of test compound 27 in solution.
[0104] Preparation of compound 27 -5 The UV-visible absorption spectrum of 5 mL of M toluene solution was tested at room temperature. The test results are as follows: Figure 1 As shown, it can be seen that the absorption of the complex in the long wavelength region of 380-500nm is the charge transition from the carbazole ligand to the carbene ligand.
[0105] Test Example 2:
[0106] Fluorescence spectrum of test compound 27 in solution.
[0107] Preparation of compound 27 -4 The fluorescence spectrum of 5 mL of toluene solution of M was measured at room temperature with an excitation wavelength of 400 nm. The test results are as follows: Figure 2 As shown, the compound exhibits obvious charge transfer broad-peak emission properties in toluene solution, with an emission peak at 585 nm.
[0108] Test Example 3:
[0109] Fluorescence spectrum of test compound 27 in doped film.
[0110] Compound 27 was doped into the host material mCP at 10%, and the fluorescence spectrum was measured at room temperature with an excitation wavelength of 330 nm. The test results are as follows: Figure 3 As shown, it can be seen that the main material mCP of the compound exhibits obvious charge transfer state broad peak emission properties, and its emission peak is 520nm.
[0111] Test Example 4:
[0112] The transient photoinduced spectral decay curve of the test compound 27 in solution.
[0113] Preparation of compound 27 -4 The transient photoinduced spectral decay curve of 5 mL of M toluene solution was tested at room temperature with an excitation wavelength of 373.2 nm. The test results are as follows: Figure 4 As shown, the compound exhibits an extremely short delayed fluorescence lifetime in deoxygenated toluene solution, indicating that triplet excitons are involved in its luminescence process, and its lifetime is 101ns.
[0114] Test Example 5:
[0115] Transient photoinduced spectral decay curve of test compound 27 in doped film.
[0116] Compound 27 was doped into the host material mCP at 10%, and the transient photoinduced spectral decay curve was tested at room temperature with an excitation wavelength of 373.2 nm. The test results are shown in Figure 2. Figure 5 As shown, the compound exhibits an extremely short delayed fluorescence lifetime in the host material mCP, indicating that triplet excitons are involved in its luminescence process, and its lifetime is 532ns.
[0117] The above test results show that the metal complex based on carbene-gold(I)-arylamine derivative described in the present invention has significant thermally activated delayed fluorescence properties, and has a shorter delayed fluorescence lifetime and a faster reverse intersystem crossing process compared to traditional pure organic thermally activated delayed fluorescence materials.
[0118] In summary, the present invention provides a thermally activated delayed fluorescence material based on carbene-gold(I)-arylamine derivatives. The heavy atom effect of gold atoms significantly increases the orbital-spin coupling between singlet and triplet states in the excited state, greatly improving the reverse intersystem crossing rate of triplet excitons and shortening the delayed fluorescence lifetime, thereby reducing the quenching of triplet excitons at high brightness, which is beneficial to reducing the device efficiency roll-off. Furthermore, the light color can be easily adjusted by using donors with different electron-donating abilities, thereby realizing a full-color OLED.
[0119] It should be understood that the above examples are not limitations of the embodiments of the present invention. For ordinary technicians in this field, different forms of changes can be made based on the above description, and it is impossible to enumerate them all here. All related improvements and changes should fall within the scope of protection of the claims attached to the present invention.
Claims
1. A thermally activated delayed fluorescent material based on carbene-gold(I)-arylamine derivatives, characterized in that: The general structural formula of the thermally activated delayed fluorescent material is shown in Formula A or Formula B: Wherein R is a protecting group, R1-R8 are the same or different and are independently selected from hydrogen, halogen, trifluoromethyl, cyano, C1-C4 alkyl, C1-C6 alkoxy, substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted C5-C 30 heteroaryl; Or adjacent two of R1-R8 are connected to each other to form C6-C 30 Aryl, C5-C 30 heteroaryl; The substituted C6-C 30 Aryl, substituted C5-C 30 The heteroaryl group contains 1-8 substituents, and the substituents are independently selected from hydrogen, halogen, cyano, C1-C4 alkyl, C6-C 30 Aryl, C5-C 30 Any one of heteroaryl, substituted or unsubstituted diarylamino; The protecting group is one of the following structures:
2. A thermally activated delayed fluorescent material based on a carbene-gold(I)-arylamine derivative according to claim 1, characterized in that: It has the following specific structure:
3. The method for preparing a thermally activated delayed fluorescent material based on a carbene-gold (I)-arylamine derivative according to any one of claims 1 to 2, characterized in that: The synthetic route is as follows: The preparation method comprises the following steps: A carbene intermediate and an aromatic amine derivative are added to an organic solvent, and a nucleophilic substitution reaction is carried out under base catalysis to obtain a thermally activated delayed fluorescent material.
4. The method for preparing a thermally activated delayed fluorescent material based on a carbene-gold (I)-arylamine derivative according to claim 3, characterized in that: The bases used are sodium hydride, potassium hydride, sodium tert-butoxide, potassium tert-butoxide, potassium carbonate, and cesium carbonate.
5. The method for preparing a thermally activated delayed fluorescent material based on a carbene-gold (I)-arylamine derivative according to claim 3, characterized in that: The nucleophilic substitution reaction is carried out at room temperature, and the reaction time is 0.5-48 hours.
6. The method for preparing a thermally activated delayed fluorescent material based on a carbene-gold (I)-arylamine derivative according to claim 3, characterized in that: The nucleophilic substitution reaction is carried out in tetrahydrofuran, 1,4-dioxane and acetone.
7. The method for preparing a thermally activated delayed fluorescent material based on a carbene-gold (I)-arylamine derivative according to claim 3, further comprising a purification step of the synthesized thermally activated delayed fluorescent material by recrystallization and sublimation.
8. Use of a thermally activated delayed fluorescent material based on a carbene-gold (I)-arylamine derivative according to any one of claims 1-2, characterized in that , used as luminescent material in electroluminescent devices.
9. An organic electroluminescent device, characterized in that: The light-emitting layer of the organic electroluminescent device comprises the thermally activated delayed fluorescent material based on a carbene-gold (I)-arylamine derivative as claimed in claim 8.