Thermally Activated Delayed Fluorescence Materials Based on Amide Derivatives, Preparation Methods Thereof, and Applications Thereof

Abstract

The present invention relates to a planar amide derivative thermally activated delayed fluorescence material represented by formula (1), and its preparation method and application. The compound has a highly twisted molecular structure, and such molecules have high molecular rigidity, which is beneficial to inhibiting intra-molecular and inter-molecular vibrational and rotational relaxations, achieving high light efficiency. In addition, it also has a small singlet-triplet energy gap (<0.2 eV), enabling the planar amide derivative of the present invention to possess thermally activated delayed fluorescence properties. Compared with the commercial iridium complex Flrpic, the electroluminescent device prepared using the planar amide derivative thermally activated delayed fluorescence material of the present invention has a higher external quantum efficiency.

Description

Technical Field

[0001] The present invention specifically relates to an amide derivative thermally activated delayed fluorescence material, a preparation method thereof, and an application thereof, belonging to the technical field of application of organic optoelectronic materials. Background Art

[0002] Organic light-emitting materials have the advantages of controllable structure, low cost, environmental friendliness, etc. When applied to the field of light-emitting diodes (LEDs), they can achieve characteristics such as flexibility, self-luminescence, low driving voltage, fast response speed, wide viewing angle range, and rich colors, and have many irreplaceable advantages compared with traditional inorganic LEDs. In the past thirty years, organic electroluminescent devices have attracted extensive attention in the academic and industrial fields and have become a new generation of lighting and display technologies that are competitively developed internationally.

[0003] In order to improve the performance of organic electroluminescent devices and promote their industrialization process, various types of light-emitting materials have been extensively developed, mainly including three categories: fluorescent, noble metal phosphorescent, and thermally activated delayed fluorescence (TADF) materials. Among them, TADF materials have a small lowest singlet-triplet excitation state energy gap ΔE ST , and triplet excitons can be converted into singlet excitons through reverse intersystem crossing to emit light, and the internal quantum efficiency of the device can reach 100%, which is a type of low-cost and highly efficient organic electroluminescent material. At present, green and red light materials based on noble metal phosphorescence have been successfully commercialized, but the cost is high. After more than ten years of rapid development, the performance of green and red light devices of TADF materials has also been comparable to that of noble metal phosphorescence. However, due to the poor stability of phosphorescent and TADF materials in the blue light band. Therefore, in view of the excellent stability of fluorescent materials, the currently commercialized blue light materials are still the first-generation fluorescent materials.

[0004] Factors such as the thermal stability and film-forming property of the material affect the stability and working life of OLED devices. High thermal stability can inhibit the decomposition of the material during the preparation of the device by vacuum evaporation, and excellent film-forming property can promote the effective energy transfer between the light-emitting layer and the adjacent functional layers, thereby improving the performance of the device. Therefore, the design and development of TADF materials with short lifetime, high quantum efficiency, high stability, and excellent film-forming property are crucial for improving the performance and working life of OLED devices. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a thermally activated delayed fluorescence material of an amide derivative represented by formula (1):

[0006]

[0007] Wherein: R1 and R2 are the same or different and are independently selected from H, halogen, cyano, and the following groups that are unsubstituted or optionally substituted by one, two, or more Ra: C1-12 Alkyl, C 1-12 Alkoxy, C 6-20 Aryl, 5-22-membered heteroaryl, -N-(C 6-20 aryl)2;

[0008] The Ra is selected from C 1-12 alkyl;

[0009] R3 are the same or different and are independently selected from the following groups which are unsubstituted or optionally substituted by one, two or more Rb: C 6-20 aryl, 5-22-membered heteroaryl, -N-(C 6-20 aryl)2, or -N-(5-20-membered heteroaryl)2; or a spiro ring formed by a 5-22-membered heteroaryl and C 6-20 aryl sharing a carbon atom;

[0010] Rb is selected from the following groups: cyano, C 1-12 alkyl, C 1-12 alkoxy, C 6-20 aryl, 5-22-membered heteroaryl, -N-(C 6-20 aryl)2 or -N-(5-22-membered heteroaryl)2;

[0011] The Rb is further optionally substituted by one, two or more of the following groups: C 6-20 aryl;

[0012] n is the number of substituents R3 and is 1, 2, 3 or 4.

[0013] According to an embodiment of the present invention, the R1, R2 are the same or different and are independently selected from CN, C 1-6 alkyl, C 1-6 alkoxy, C 6-14 aryl, 5-14-membered heteroaryl, C 1-6 alkyl-substituted 5-14-membered heteroaryl, -N-(5-14-membered heteroaryl)2, -N-(C 1-6 alkyl-substituted C 6-14 aryl)2 or C 6-14 aryl-substituted 5-14-membered heteroaryl;

[0014] R3 are the same or different and are independently selected from the following groups which are unsubstituted or optionally substituted by one, two or more Rb: C 6-14 aryl, 5-14-membered heteroaryl, -N-(C 6-14 aryl)2, or -N-(5-14-membered heteroaryl)2; or a spiro ring formed by a 5-14-membered heteroaryl and C 6-14 aryl sharing a carbon atom;

[0015] Rb are the same or different and each independently selected from cyano, C 1-6 alkyl, C 1-6 alkoxy, C 6-14 aryl, 5- to 14-membered heteroaryl, -N-(C 6-14 aryl)2 or -N-(5- to 14-membered heteroaryl)2;

[0016] The Rb are further optionally substituted by one, two or more of the following groups: C 6-14 aryl.

[0017] According to a preferred embodiment of the present invention, R1 and R2 are the same and are selected from methyl, tert-butyl, phenyl, carbazolyl, CN, 9,9-dimethylacridinyl, methoxy, -N(phenyl)2, -N(p-tert-butylphenyl)2, -N(p-methylphenyl)2, phenoxazinyl, phenothiazinyl or phenazinyl.

[0018] According to a preferred embodiment of the present invention, R3 is selected from acridinyl, 9,9-dimethylacridinyl, tert-butyl-substituted acridinyl, phenoxazinyl, phenothiazinyl, phenazinyl, 10H-phenoselenazinyl, -N(phenyl)2, -N(p-tert-butylphenyl)2, -phenyl-N(phenyl)2, 9,9-diphenylacridinyl, carbazolyl, 3,6-dimethylcarbazolyl, 1,3,6,8-tetramethylcarbazolyl, 3,6-di-tert-butyl-substituted carbazolyl, 3,6-diphenyl-substituted carbazolyl, 3,6-dimethoxy-substituted carbazolyl, 3-carbazolyl-substituted carbazolyl, 3,6-carbazolyl-substituted carbazolyl or the following group:

[0019]

[0020]

[0021] In some specific embodiments of the present invention, the amide derivative represented by formula (1) is selected from one of the following structures:

[0022]

[0023]

[0024]

[0025]

[0026] According to an embodiment of the present invention, the amide derivative represented by formula (1) is a thermally activated delayed fluorescence material. The present invention also provides a method for preparing the above amide derivative represented by formula (1), comprising the following steps:

[0027]

[0028] Compound 1a reacts with compound R3-H to obtain the compound shown in formula (I);

[0029] Among them, R1, R2, R3, and n are defined as described above; L is a leaving group, such as a halogen.

[0030] The present invention also provides the use of the amide derivative shown in the above formula (1) as a thermally activated delayed fluorescence material in the preparation of organic electronic devices, preferably in the preparation of organic electroluminescent devices.

[0031] According to the embodiments of the present invention, the amide derivative has photoluminescence or electroluminescence properties and can emit ultraviolet light, visible light or infrared light. Preferably, the planar amide derivative is a thermally activated delayed fluorescence material.

[0032] The present invention also provides an organic electroluminescent device, which includes two electrodes and an organic layer located between the electrodes, and the organic layer includes the amide derivative shown in the above formula (1).

[0033] Preferably, the organic layer is one, two or more of an injection layer, a transport layer, a light-emitting layer, and a blocking layer.

[0034] Preferably, the amide derivative shown in the formula (1) is located in the light-emitting layer.

[0035] The present invention also provides a method for preparing the organic electroluminescent device, including the following steps: sequentially disposing an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode on a substrate.

[0036] Preferably, the anode, the hole injection layer, the hole transport layer, the electron blocking layer, the light-emitting layer, the hole blocking layer, the electron transport layer, the electron injection layer, and the cathode are disposed by evaporation, spin coating or inkjet, for example, by evaporation.

[0037] More preferably, the evaporation is carried out under a vacuum condition, for example, under a condition where the vacuum degree is lower than 2×10 -5 Pa, and further preferably, the evaporation speed is 0.2 nm / s.

[0038] Beneficial effects

[0039] 1. The present invention provides a class of thermally activated delayed fluorescence materials, which use rigid and planar amide derivatives as the structural center and can be applied to the field of electroluminescence and can emit ultraviolet light, visible light or infrared light.

[0040] 2. Using the compound provided by the present invention as the light-emitting layer in the organic electroluminescent device, the obtained organic electroluminescent device has good device performance, and the specific advantages are as follows:

[0041] (1) By introducing a locked amide backbone and using planar amide derivatives as the electron acceptor center, the molecules involved in the present invention have a highly twisted molecular structure. Such molecules have high molecular rigidity, which is beneficial to suppressing intra- and intermolecular vibrational and rotational relaxations, thereby improving the luminescence efficiency. In addition, they also have a small singlet-triplet energy gap (<0.2 eV), enabling the planar amide derivatives of the present invention to possess thermally activated delayed fluorescence properties. From the perspective of molecular structure, the planar configuration can ensure the thermal stability of the molecules, effectively suppress the deformation of the molecules in the excited state while suppressing non-radiative inactivation, thereby improving the photoluminescence quantum yield (PLQY) of the material and the efficiency and stability of its electroluminescent device. In addition, the horizontal orientation of the material depends on the anisotropy of the molecular structure. Among them, linear, planar, and disc-shaped molecules have a more horizontal molecular orientation in the thin film, which is beneficial to the light extraction efficiency of the device and is suitable for use as an electroluminescent material in the preparation of OLEDs.

[0042] (2) Compared with the commercial iridium complex Flrpic, the electroluminescent device prepared using the thermally activated delayed fluorescence material of the planar amide derivative of the present invention has excellent performance (stable emission color, high luminescence efficiency, and small device efficiency roll-off, that is, good stability).

[0043] (3) The preparation process of the thermally activated delayed fluorescence material of the planar amide derivative of the present invention is simple, and the raw materials used in the synthesis are cheap and easily available. Such materials have good application effects in electroluminescent devices and have prospects for industrialization and commercialization.

[0044] Term Definition and Explanation

[0045] The term "halogen" refers to F, Cl, Br, and I. In other words, F, Cl, Br, and I can be described as "halogen" in this specification.

[0046] The term "C 1-12 alkyl" should be understood to represent a straight-chain or branched-chain saturated monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably C 1-10 alkyl. "C 1-10"Alkyl" should be understood to mean a straight-chain or branched-chain saturated monovalent hydrocarbon group having 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms. The alkyl groups are, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl or 1,2-dimethylbutyl, etc. or their isomers. In particular, the group has 1, 2, 3, 4, 5, 6 carbon atoms ("C 1-6 alkyl"), such as methyl, ethyl, propyl, butyl, isopropyl, isobutyl, sec-butyl, tert-butyl, and more particularly, the group has 1, 2 or 3 carbon atoms ("C 1-3 alkyl"), such as methyl, ethyl, n-propyl or isopropyl.

[0047] The term "C 6-20 aryl" should be understood to mean a monocyclic, bicyclic or tricyclic hydrocarbon ring having 6 to 60 carbon atoms that is monovalent, aromatic or partially aromatic, preferably "C 6-14 aryl". The term "C 6-14 aryl" should be understood to mean a monocyclic, bicyclic or tricyclic hydrocarbon ring having 6, 7, 8, 9, 10, 11, 12, 13 or 14 carbon atoms that is monovalent, aromatic or partially aromatic ("C 6-14 aryl"), especially a ring having 6 carbon atoms ("C6 aryl"), such as phenyl; or biphenyl, or a ring having 9 carbon atoms ("C9 aryl"), such as indanyl or indenyl, or a ring having 10 carbon atoms ("C 10 aryl"), such as tetrahydronaphthyl, dihydronaphthyl or naphthyl, or a ring having 13 carbon atoms ("C 13 aryl"), such as fluorenyl, or a ring having 14 carbon atoms ("C 14 aryl"), such as anthryl.

[0048] The term "5-22 membered heteroaryl" is to be understood as including monocyclic, bicyclic or tricyclic aromatic ring systems that are monovalent, having 5 to 22 ring atoms and containing 1 to 5 heteroatoms independently selected from N, O and S, such as "5-14 membered heteroaryl". The term "5-14 membered heteroaryl" is to be understood as including monocyclic, bicyclic or tricyclic aromatic ring systems that are monovalent, having 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 ring atoms, especially 5 or 6 or 9 or 10 carbon atoms, and containing 1 to 5, preferably 1 to 3 heteroatoms independently selected from N, O and S and, additionally in each case, may be benzo-fused. In particular, heteroaryl is selected from thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, thia-4H-pyrazolyl, etc. and their benzo derivatives, such as benzofuryl, benzothienyl, benzoxazolyl, benzisoxazolyl, benzimidazolyl, benzotriazolyl, indazolyl, indolyl, isoindolyl, etc.; or pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, etc. and their benzo derivatives, such as quinolinyl, quinazolinyl, isoquinolinyl, etc.; or azocinyl, indolizinyl, purinyl, etc. and their benzo derivatives; or cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, naphthyridinyl, pteridinyl, carbazolyl, acridinyl, phenazinyl, phenothiazinyl, phenoxazinyl, etc.

[0049] Unless otherwise stated, heterocyclic group, heteroaryl or heteroarylene includes all their possible isomeric forms, such as their positional isomers. Thus, for some illustrative non-limiting examples, pyridyl or pyridinylene includes pyridin-2-yl, pyridin-2-ylidene, pyridin-3-yl, pyridin-3-ylidene, pyridin-4-yl and pyridin-4-ylidene; thienyl or thienylene includes thien-2-yl, thien-2-ylidene, thien-3-yl and thien-3-ylidene.

[0050] The above definition of the term "C 1-20 alkyl" also applies to other terms containing "C 1-20 alkyl", such as the term "C 1-20 alkoxy", "halo C 1-20 alkyl", etc. Description of the Drawings

[0051] Figure 1 Steady-state photoluminescence spectra of Compounds 1-3 of Example 5 of the present invention as guest luminescent materials, doped 20 wt% in the host material mCP film and Compounds 1-13, 1-17 of Examples 7 and 11 as guest luminescent materials, doped 20 wt% in the host material BCPO film.

[0052] Figure 2Transient decay spectra (at room temperature) of Compound 1-3 of Example 5 of the present invention as the guest luminescent material doped at 20 wt% in the host material mCP film.

[0053] Figure 3 Transient decay spectra (at room temperature) of Compound 1-13 of Example 7 of the present invention as the guest luminescent material doped at 20 wt% in the host material BCPO film.

[0054] Figure 4 Transient decay spectra (at room temperature) of Compound 1-17 of Example 11 of the present invention as the guest luminescent material doped at 20 wt% in the host material BCPO film.

[0055] Figure 5 Thermogravimetric analysis (TGA) curves of Compounds 1-3, 1-13, and 1-17 corresponding to Examples 5, 7, and 11 of the present invention respectively. The thermal decomposition temperatures of Compounds 1-3, 1-13, and 1-17 are 363 °C, 476 °C, and 380 °C respectively, indicating good thermal stability of the compounds.

[0056] Figure 6 External quantum efficiency, power efficiency, and current efficiency - brightness curves of the organic light-emitting devices of Examples 5, 7, and 11 of the present invention. It can be known from the curve analysis that the light-emitting efficiencies of the organic light-emitting devices corresponding to the compounds prepared in Examples 5, 7, and 11 are all relatively high.

[0057] Figure 7 Structural diagram of the organic light-emitting device fabricated using the compound of the present invention.

[0058] Among them, 1 - transparent glass substrate, 2 - anode, 3 - hole injection layer, 4 - hole transport layer, 5 - electron blocking layer, 6 - light-emitting layer, 7 - hole blocking layer, 8 - electron transport layer, 9 - electron injection layer, 10 - cathode. Detailed implementation manners

[0059] The technical solutions of the present invention will be further described in detail below with reference to specific examples. It should be understood that the following examples are only for illustrative and explanatory purposes of the present invention, and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0060] Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available products, or can be prepared by known methods.

[0061] Example 1 Synthesis of Compound 1-1

[0062] [Synthesis of Compound P1]

[0063]

[0064] A mixture of aluminum chloride (0.16 g, 1.2 mmol), carbazole (0.17 g, 1 mmol) and dichloromethane (10 ml) was placed under vacuum, backfilled with argon three times, and then stirred at 0°C for 15 minutes before adding 4-chloro-2-bromobenzoyl chloride (0.24 g, 1.1 mmol). After reacting at 40°C for 4 hours, dilute hydrochloric acid was slowly added to the flask to terminate the reaction. Extracted with CH2Cl2 (3×50 ml), the organic phase was collected, dried with anhydrous sodium sulfate, and the solvent was removed to obtain a crude product. A mixed solvent of petroleum ether and dichloromethane was used as an eluent, separated and purified by a silica gel column, and dried in vacuo to obtain a white solid (0.25 g, yield: 65%).

[0065] [Synthesis of Compound P2]

[0066] A mixture of P1 (0.25 g, 0.65 mmol), 4,7-bis(4-methoxyphenyl)benzo[C][1,2,5]thiadiazole (CAS: 503862-08-6) (24 mg, 0.07 mmol), N,N-diisopropylethylamine (243 μL, 1.4 mmol) and 1,2-dichloroethane (10 mL) was placed under vacuum at room temperature and backfilled with argon three times. After irradiation at 450-460 nm (45 W blue light) for 24 hours, the mixture was filtered, washed three times with n-hexane, and dried in vacuum to obtain a white solid P2 (0.14 g, yield: 71%).

[0067] [Synthesis of Compound 1-1]

[0068] The synthetic route of compound 1-1 is as follows:

[0069]

[0070] [Synthesis of Compound 1-1]

[0071] A mixture of P2 (0.31 g, 1.0 mmol), 9,9-dimethyl-9,10-dihydroacridine (0.29 g, 1.4 mmol), tri-tert-butylphosphine tetrafluoroborate (52 mg, 0.18 mmol), sodium tert-butoxide (0.29 g, 3 mmol), palladium acetate (20 mg, 0.09 mmol) and dry toluene (20 mL) was placed in a vacuum and backfilled with argon three times. After reflux at 110°C for 24 hours, it was cooled to room temperature and the solvent was removed under vacuum. It was extracted with CH2Cl2 (3×50 mL), the organic phase was collected, dried over anhydrous sodium sulfate, and the solvent was removed to obtain a crude product. It was separated and purified by silica gel column using a mixed solvent of petroleum ether and dichloromethane as the eluent, and finally a light yellow solid (0.43 g, yield: 91%) was obtained after vacuum drying. 11H NMR (500 MHz, CDCl3) δ 8.92 (dd, J = 39.3, 8.2 Hz, 2H), 8.44–7.93 (m, 4H), 7.84–7.40 (m, 6H), 7.06–6.91 (m, 4H), 6.45–6.31 (m, 2H), 1.77 (s, 6H).

[0072] MS (EI): m / z 476.19 [M + ; Combustion elemental analysis: C 34 H 24 N2O (%) Calculated: C 85.69; H 5.08; N 5.88; O 3.36; Found: C 85.87, H 5.10, N 5.85, O 3.30.

[0073] Synthesis of Compound 1-25 in Example 2

[0074] The synthetic route of Compound 1-25 is as follows:

[0075]

[0076] Except for using 10H-spiro[acridine-9,9'-fluorene] (0.46 g, 1.4 mmol) to replace 9,9-dimethyl-9,10-dihydroacridine, the remaining steps were the same as those in the synthesis of Compound 1-1, and finally a pale yellow solid (0.66 g, yield: 88%) was obtained.

[0077] MS (EI): m / z 598.20 [M + ; Combustion elemental analysis: C 44 H 26 N2O (%) Calculated: C 88.27; H 4.38; N 4.68; O 2.67; Found: C 88.37, H 4.59, N 4.71, O 2.70.

[0078] Synthesis of Compound 1-20 in Example 3

[0079] The synthetic route of Compound 1-20 is as follows:

[0080]

[0081] [Synthesis of Compound P3]

[0082] Except for using 3,6-diphenylcarbazole (0.32 g, 1 mmol) to replace carbazole, the remaining steps were the same as those in the synthesis of Compound P1, and finally a white solid (0.25 g, yield: 65%) was obtained.

[0083] [Synthesis of Compound P4]

[0084] Except for using P3 (0.25 g, 0.65 mmol) to replace carbazole, the remaining steps were the same as those in the synthesis of compound P2, and finally a white solid (0.14 g, yield: 71%) was obtained.

[0085] [Synthesis of Compounds 1-20]

[0086] Referring to the preparation process of compound 1-1, using compound P4 and 10,10-diphenyl-5,10-dihydrodibenzo[b,e][1,4]azasilinane (0.49 g, 1.4 mmol) as raw materials for reaction, and finally a pale yellow solid (0.66 g, yield: 88%) was obtained.

[0087] MS(EI): m / z 768.26 [M + ; Combustion elemental analysis: C 55 H 36 N2OSi (%) Calculated: C 85.91; H 4.72; N 3.64; O 2.08; Si 3.65; Found: C 85.96, H 4.69, N 3.58, O 2.11, Si 3.64.

[0088] Synthesis of Compound 1-23 in Example 4

[0089] The synthesis route of compound 1-23 is as follows:

[0090]

[0091] [Synthesis of Compound P5]

[0092] Except for using 3,6-di-tert-butylcarbazole (0.17 g, 1 mmol) to replace carbazole, the remaining steps were the same as those in the synthesis of compound P1, and finally a white solid (0.26 g, yield: 65%) was obtained.

[0093] [Synthesis of Compound P6]

[0094] Except for using P5 (0.25 g, 0.65 mmol) to replace carbazole, the remaining steps were the same as those in the synthesis of compound P2, and finally a white solid (0.14 g, yield: 75%) was obtained.

[0095] [Synthesis of Compound 1-23]

[0096] Referring to the preparation process of compound 1-1, using triphenylamine (0.35 g, 1.4 mmol) and compound P6 as raw materials, and finally a pale yellow solid (0.66 g, yield: 88%) was obtained.

[0097] MS(EI): m / z 624.31 [M + ; Combustion elemental analysis: C 45 H 40 N2O(%) Calculated: C 86.50; H 6.45; N 4.48; O 2.56; Found: C 86.55, H 6.44, N 4.51, O 2.59.

[0098] Example 5 Synthesis of Compound 1-3

[0099] The synthetic route of Compound 1-3 is as follows:

[0100]

[0101] Except for using P6 (0.42 g, 1 mmol) to replace P2, the remaining steps are the same as those in the synthesis of Compound 1-1. Finally, a pale yellow solid (0.52 g, yield: 88%) was obtained.

[0102] MS(EI): m / z 588.31 [M + ; Combustion elemental analysis: C 42 H 40 N2O(%) Calculated: C 85.68; H 6.85; N 4.76; O 2.72; Found: C 85.65, H 6.84, N 4.71, O 2.79.

[0103] Example 6 Synthesis of Compound 1-45

[0104] The synthetic route of Compound 1-45 is as follows:

[0105]

[0106] Except for using 5H-indolo[3,2-b]acridine (CAS No.: 2055831-73-5) (0.49 g, 1.3 mmol) to replace 9,9-dimethyl-9,10-dihydroacridine, the remaining steps are the same as those in the synthesis of Compound 1-3. Finally, a pale yellow solid (0.53 g, yield: 70%) was obtained.

[0107] MS(EI): m / z 753.37 [M + ; Combustion elemental analysis: C 54 H 47 N3O(%) Calculated: C 86.02; H 6.28; N 5.57; O 2.12; Found: C 86.05, H 6.24, N 5.51, O 2.10.

[0108] Example 7 Synthesis of Compound 1-13

[0109] The synthetic routes of Compounds 1-13 are shown as follows:

[0110]

[0111] Except for using phenoxazine (260 mg, 1.4 mmol) to replace 9,9-dimethyl-9,10-dihydroacridine, the remaining steps are the same as those in the synthesis of Compounds 1-3, and finally a pale yellow solid (0.6 g, yield: 85%) is obtained.

[0112] MS(EI): m / z 562.26 [M + ; Elemental analysis by combustion method: C 39 H 34 N2O2 (%) Calculated: C 83.24; H 6.09; N 4.98; O 5.69; Found: C 83.25, H 6.04, N 4.91, O 5.71.

[0113] Example 8 Synthesis of Compound 1-18

[0114] The synthetic route of Compound 1-18 is shown as follows:

[0115]

[0116] Except for using phenothiazine (0.40 g, 1.2 mmol) to replace 10,10-diphenyl-5,10-dihydrodibenzo[b,e][1,4]azasilinane, the remaining steps are the same as those in the synthesis of Compound 1-20, and finally a pale yellow solid (0.35 g, yield: 70%) is obtained.

[0117] MS(EI): m / z 618.18 [M + ; Elemental analysis by combustion method: C 43 H 26 N2OS (%) Calculated: C 83.47; H 4.24; N 4.53; O 2.59; S 5.18; Found: C 83.45, H 4.24, N 4.51, O 2.55; S 5.20.

[0118] Example 9 Synthesis of Compound 1-34

[0119] The synthetic route of Compound 1-34 is shown as follows:

[0120]

[0121] Except for using 3,6-dimethoxy-9H-carbazole (0.27 g, 1.2 mmol) to replace 9,9-dimethyl-9,10-dihydroacridine, the remaining steps were the same as those for the synthesis of Compound 1-1, and finally a pale yellow solid (0.25 g, yield: 70%) was obtained.

[0122] MS(EI): m / z 494.16[M + ; Combustion elemental analysis: C 33 H 22 N2O3(%) Calculated: C 80.15; H 4.48; N 5.66; O 9.71; Found: C 80.15, H 4.44, N 5.61, O 9.75.

[0123] Example 10 Synthesis of Compound 1-50

[0124] The synthetic route of Compound 1-50 is as follows:

[0125]

[0126] [Synthesis of Compound P7]

[0127] Except for using 2-bromo-3,5-difluorobenzoyl chloride (0.7 g, 2.75 mmol) to replace 4-chloro-2-bromobenzoyl chloride, the remaining steps were the same as those in the synthesis of P1, and finally a white solid (0.68 g, yield: 72%) was obtained.

[0128] [Synthesis of Compound P8]

[0129] The synthetic procedure referred to P2, and finally a white solid (0.41 g, yield: 69%) was obtained.

[0130] [Synthesis of Compound 1-50]

[0131] Dissolve 3,6-di-tert-butylcarbazole (0.45 g, 1.4 mmol) in 10 mL of dry THF and purged with argon three times. After 10 minutes, add NaH (57-63% oily, 6.7 mmol), stir at room temperature for 1 hour, dissolve P8 (1 mmol) in 5 mL of dry THF, add it slowly, stir the mixture at room temperature for 5 hours, quench the reactant with ice water, and remove the organic solvent. Add 200 mL of water, sonicate for 30 min, filter to obtain the crude product, purify it by recrystallization from acetone and flash column chromatography (DCM), and finally obtain the corresponding product after vacuum drying, a pale yellow solid (0.88 g, yield: 90%).

[0132] MS(EI): m / z 975.51[M + ; Combustion elemental analysis: C 71 H65 Calculated values for N3O(%): C 87.35; H 6.71; N 4.30; O 1.64; Measured values: C 87.36, H 6.74, N 4.31, O 1.65.

[0133] Synthesis of Compound 1-17 in Example 11

[0134] The synthetic route of Compound 1-17 is as follows:

[0135]

[0136] Except for using phenoxazine (0.22 g, 1.2 mmol) to replace 10,10-diphenyl-5,10-dihydrodibenz[b,e][1,4]azasilinane, the remaining steps are the same as those for the synthesis of Compound 1-20, and finally a pale yellow solid (0.35 g, yield: 70%) is obtained.

[0137] MS(EI): m / z 602.20[M + ; Combustion elemental analysis: C 43 H 26 Calculated values for C H N2O2(%): C 85.69; H 4.35; N 4.65; O 5.31; Measured values: C 85.65, H 4.64, N 5.33, O 5.35.

[0138] Preparation of Organic Electroluminescent Device 1 (OLED-1) in Example 12

[0139] In this example, Compound 1-1 prepared in Example 1 is used as the doped luminescent material, indium tin oxide (ITO) as the anode, commercial compound mCP as the host material, HAT-CN as the hole injection material, TAPC as the hole transport material, TCTA as the electron blocking material, DPEPO as the hole blocking material, TmPyPB as the electron transport material, Liq as the electron injection material, and metal aluminum Al as the cathode material. The device structure is: ITO / HAT-CN / TAPC / TCTA / mCP:Compound 1-1(20wt%) / DPEPO / TmPyPB / Liq / Al. Where 20wt% is the weight percentage of Compound 1-1 in the host material.

[0140] Specifically, the device fabrication process is as follows: The transparent conductive glass substrate with an anode ITO is cleaned multiple times using a cleaner, rinsed thoroughly with deionized water, and then successively placed in deionized water, acetone, and isopropyl alcohol solvents for ultrasonic treatment for more than 15 minutes each. After cleaning, it is placed in an environment of high-purity argon to dry the solvent on the surface of the glass substrate, and then placed in an ultraviolet ozone machine for 15 minutes. Carefully place the cleaned and processed ITO in the chamber of the vacuum evaporation device, evacuate to below 2×10 -5 Pa and then start evaporating each functional layer: First, evaporate HAT-CN onto the glass substrate at a rate of 0.2 nm / s to 10 nm as the hole injection layer; subsequently, evaporate TAPC at an evaporation rate of 0.2 nm / s to 60 nm as the hole transport layer; subsequently, evaporate TCTA at an evaporation rate of 0.2 nm / s to 10 nm as the electron blocking layer; subsequently, co-evaporate the host material mCP and compound 1-1 from two sources at an evaporation rate of 0.2 nm / s to 30 nm as the light-emitting layer; subsequently, evaporate DPEPO at an evaporation rate of 0.2 nm / s to 10 nm as the hole blocking layer; subsequently, evaporate TmPyPB at an evaporation rate of 0.2 nm / s to 40 nm as the electron transport layer; subsequently, evaporate Liq at an evaporation rate of 0.02 nm / s to 1 nm as the electron injection layer; finally, evaporate Al at an evaporation rate of 0.5 nm / s to 100 nm as the cathode. The structure of the organic electroluminescent device is as Figure 7 shown.

[0141] Preparation of Organic Electroluminescent Device 2 (OLED-2) in Example 13

[0142] Except for using compound 1-25 as the light-emitting layer material instead of compound 1-1, OLED-2 is prepared under the same production conditions as OLED-1.

[0143] Preparation of Organic Electroluminescent Device 3 (OLED-3) in Example 14

[0144] In this example, compound 1-20 prepared in Example 3 is used as the doped light-emitting material, indium tin oxide (ITO) is used as the anode, a commercial compound BCPO is used as the host material, HAT-CN is used as the hole injection material, TAPC is used as the hole transport material, mCP is used as the electron blocking material, DPEPO is used as the hole blocking material, TmPyPB is used as the electron transport material, LiF is used as the electron injection material, and metallic aluminum (Al) is used as the cathode material. The device structure is: ITO / HAT-CN / TAPC / mCP / BCPO: compound 1-20 (20 wt%) / DPEPO / TmPyPB / LiF / Al. The structure of the organic electroluminescent device is as Figure 7 shown.

[0145] Specifically, the device preparation process is as follows: The transparent conductive glass substrate with an anode ITO is cleaned multiple times with a cleaner, rinsed thoroughly with deionized water, and then successively placed in deionized water, acetone, and isopropanol solvents for ultrasonic treatment for more than 15 minutes each. After cleaning, it is placed in an environment of high-purity argon to dry the solvent on the surface of the glass substrate, and then placed in an ultraviolet ozone machine for 15 minutes. Carefully place the cleaned and treated ITO in the chamber of the vacuum evaporation device, evacuate to below 2×10 -5 Pa and then start evaporating each functional layer: First, evaporate HAT-CN at a rate of 0.2 nm / s on the glass substrate to 10 nm as the hole injection layer; subsequently, evaporate TAPC at an evaporation rate of 0.2 nm / s to 50 nm as the hole transport layer; subsequently, evaporate TCTA at an evaporation rate of 0.2 nm / s to 10 nm as the electron blocking layer; subsequently, co-evaporate the host material BCPO and compound 1-20 at a rate of 0.2 nm / s for 20 nm as the light-emitting layer; subsequently, evaporate DPEPO at an evaporation rate of 0.2 nm / s to 10 nm as the hole blocking layer; subsequently, evaporate TmPyPB at an evaporation rate of 0.2 nm / s to 30 nm as the electron transport layer; subsequently, evaporate LiF at an evaporation rate of 0.02 nm / s to 1 nm as the electron injection layer; finally, evaporate Al at an evaporation rate of 0.5 nm / s to 100 nm as the cathode.

[0146] Preparation of Organic Electroluminescent Device 4 (OLED-4) in Example 15

[0147] OLED-4 was prepared under the same production conditions as OLED-3, except that compound 1-23 was used as the light-emitting layer material instead of compound 1-20.

[0148] Preparation of Organic Electroluminescent Device 5 (OLED-5) in Example 16

[0149] OLED-5 was prepared under the same production conditions as OLED-3, except that compound 1-3 was used as the light-emitting layer material instead of compound 1-20.

[0150] Preparation of Organic Electroluminescent Device 6 (OLED-6) in Example 17

[0151] OLED-6 was prepared under the same production conditions as OLED-3, except that compound 1-45 was used as the light-emitting layer material instead of compound 1-20.

[0152] Preparation of Organic Electroluminescent Device 7 (OLED-7) in Example 18

[0153] OLED-7 was prepared under the same production conditions as OLED-3, except that Compound 1-13 was used as the light-emitting layer material instead of Compound 1-20.

[0154] Example 19 Preparation of Organic Electroluminescent Device 8 (OLED-8)

[0155] OLED-8 was prepared under the same production conditions as OLED-3, except that Compound 1-18 was used as the light-emitting layer material instead of Compound 1-20.

[0156] Example 20 Preparation of Organic Electroluminescent Device 9 (OLED-9)

[0157] OLED-9 was prepared under the same production conditions as OLED-1, except that Compound 1-34 was used as the light-emitting layer material instead of Compound 1-1.

[0158] Example 21 Preparation of Organic Electroluminescent Device 10 (OLED-10)

[0159] In this example, Compound 1-50 prepared in Example 10 was used as the doped light-emitting material, indium tin oxide (ITO) as the anode, commercial compound mCP as the host material, HAT-CN as the hole injection material, TAPC as the hole transport material, TCTA as the electron blocking material, DPEPO as the hole blocking material, B3PYMPM as the electron transport material, Liq as the electron injection material, and metallic aluminum (Al) as the cathode material. The device structure was: ITO / HAT-CN / TAPC / TCTA / mCP:Compound 1-50 (20 wt%) / DPEPO / B3PYMPM / Liq / Al. The structure of the organic electroluminescent device is as Figure 7 shown.

[0160] Specifically, the device preparation process was as follows: The transparent conductive glass substrate with the anode ITO was cleaned multiple times with a cleaner, rinsed thoroughly with deionized water, and then successively placed in deionized water, acetone, and isopropyl alcohol solvents for ultrasonic treatment for more than 15 minutes each. After cleaning, it was placed in an environment of high-purity argon to dry the solvent on the surface of the glass substrate, and then placed in an ultraviolet ozone machine for 15 minutes. The cleaned and treated ITO was carefully placed in the chamber of the vacuum evaporation device, and the vacuum was pumped to less than 2×10 -5After reaching Pa, the evaporation of each functional layer begins: First, HAT-CN is evaporated onto the glass substrate at a rate of 0.2 nm / s to a thickness of 10 nm as the hole injection layer; subsequently, TAPC is evaporated at a deposition rate of 0.2 nm / s to 50 nm as the hole transport layer; subsequently, TCTA is evaporated at a deposition rate of 0.2 nm / s to 10 nm as the electron blocking layer; subsequently, the host material mCP and compound 1-50 are co-evaporated from two sources at a deposition rate of 0.2 nm / s to 20 nm as the light-emitting layer; subsequently, DPEPO is evaporated at a deposition rate of 0.2 nm / s to 10 nm as the hole blocking layer; subsequently, B3PYMPM is evaporated at a deposition rate of 0.2 nm / s to 40 nm as the electron transport layer; subsequently, Liq is evaporated at a deposition rate of 0.02 nm / s to 1 nm as the electron injection layer; finally, Al is evaporated at a deposition rate of 0.5 nm / s to 100 nm as the cathode.

[0161] Preparation of Organic Electroluminescent Device 11 (OLED-11) in Example 22

[0162] OLED-11 was prepared under the same production conditions as OLED-3, except that compound 1-17 was used as the light-emitting layer material instead of compound 1-20. Preparation of Devices in Comparative Examples Comparative Example A (OLED-A), Comparative Example B (OLED-B), and Comparative Example C (OLED-C)

[0163] Except that the commercial iridium complex Flrpic (whose structure is shown below) was used as the light-emitting material instead of compound 1-1, 1-20, or 1-50 in the device preparation in Example 12, Example 18, and Example 21, respectively, other operations and preparation conditions were the same as those in Example 12, 18, and 21. The structure of the organic electroluminescent device is as Figure 7 shown.

[0164] The structures of the functional layer materials used in Examples 12-22 and Comparative Examples A, B, and C are as follows:

[0165]

[0166] Table 1. Comparison of OLED Device Performance in Examples 12-22 and Comparative Examples A, B, and C

[0167]

[0168]

[0169] Analysis of the device characterization test results shows that: For the OLED devices prepared with the compounds 1-3, 1-25, 1-20, 1-23, 1-3, 1-45, 1-13, 1-18, 1-34, 1-50, and 1-17 of the present invention as the light-emitting layer materials, the external quantum efficiency shows a significant improvement compared to the OLED devices prepared with the commercial iridium complex Flrpic.

[0170] From the above comparison, it can be seen that the amide compounds of the present invention can effectively improve the performance of the materials and their devices, and the preparation cost of the amide compounds is relatively low.

[0171] Test Example 1

[0172] Compound 1-3 of Example 5 of the present invention was doped as a guest light-emitting material at a concentration of 20% (20 wt%) in the host material mCP thin film; the steady-state photoluminescence spectra of Compound 1-13 of Example 7 and Compound 1-17 of Example 11 were each doped at a concentration of 20% (20 wt%) in the host material BCPO thin film as shown in Figure 1 shown. From Figure 1 it can be seen that the three compounds have efficient sky blue to green light emission in the doped thin films.

[0173] The transient decay spectrum of Compound 1-3 of Example 5 of the present invention as a guest light-emitting material doped at a concentration of 20% (20 wt%) in the host material mCP thin film is as shown in Figure 2 shown (at room temperature). From Figure 2 it can be seen that Compound 1-3 has thermally activated delayed fluorescence emission at room temperature and is a typical thermally activated delayed fluorescence material.

[0174] The transient decay spectrum of Compound 1-13 of Example 7 of the present invention as a guest light-emitting material doped at a concentration of 20% (20 wt%) in the host material BCPO thin film is as shown in Figure 3 shown (at room temperature). From Figure 3 it can be seen that Compound 1-13 has thermally activated delayed fluorescence emission at room temperature and is a typical thermally activated delayed fluorescence material. Moreover, its thermally activated delayed fluorescence lifetime is short (2.6 microseconds), which is beneficial to obtaining a small device efficiency roll-off.

[0175] The transient decay spectrum of Compound 1-17 of Example 11 of the present invention as a guest light-emitting material doped at a concentration of 20% (20 wt%) in the host material BCPO thin film is as shown in Figure 4 shown (at room temperature). From Figure 4 it can be seen that this material is a thermally activated delayed fluorescence material. Compound 1-13 has thermally activated delayed fluorescence emission at room temperature and is a typical thermally activated delayed fluorescence material. Moreover, its thermally activated delayed fluorescence lifetime is short (2.2 microseconds), which is beneficial to obtaining a small device efficiency roll-off.

[0176] The thermogravimetric analysis (TGA) curves of the compounds (Compound 1-3, 1-13, and 1-17) of Examples 5, 7, and 11 of the present invention are as Figure 5 shown. As can be Figure 5 seen, the thermal decomposition temperatures of Compound 1-3, 1-13, and 1-17 are 363 °C, 476 °C, and 380 °C, respectively, indicating that the compounds have good thermal stability.

[0177] The external quantum efficiency, power efficiency, and current efficiency-luminance curves of the organic light-emitting devices of the compounds (Compound 1-3, 1-13, and 1-17) of Examples 5, 7, and 11 of the present invention are as Figure 6 shown. From the curve analysis, it can be seen that the light-emitting efficiencies of the light-emitting devices corresponding to the compounds prepared in Examples 5, 7, and 11 are all relatively high.

[0178] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. The amide derivative shown in formula (1), Wherein: R1 and R2 are the same and are selected from H, methyl, tert-butyl, phenyl, carbazolyl, CN, 9,9-dimethylacridinyl, methoxy, -N(phenyl)2, -N(p-tert-butylphenyl)2, -N(p-methylphenyl)2, phenoxazinyl, phenothiazinyl or phenazinyl; R3 is selected from -N(phenyl)2, -N(p-tert-butylphenyl)2, -phenyl-N(phenyl)2 or the following group:

2. The amide derivative shown as follows:

3. The method for preparing the amide derivative according to claim 1, characterized in that, including the following steps: Reacting compound 1a with compound R3-H to obtain the amide derivative shown in formula (1); wherein, R1, R2, R3, n have the definitions described in claim 1; L is a leaving group.

4. The preparation method according to claim 3, wherein, L is a halogen.

5. Use of the amide derivative according to claim 1 or 2 as a thermally activated delayed fluorescence material in the preparation of an organic electronic device.

6. The use according to claim 5, wherein The organic electronic device is an organic light-emitting device.

7. An organic electroluminescent device, characterized in that, It includes two electrodes and an organic layer located between the electrodes, and the organic layer includes the amide derivative according to claim 1 or 2; The amide derivative is used as a thermally activated delayed fluorescence material.

8. The organic electroluminescent device according to claim 7, wherein, The organic layer is one, two or more of a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

9. The organic electroluminescent device according to claim 8, wherein, The amide derivative according to claim 1 or 2 is located in the light-emitting layer.

10. The method for preparing an organic electroluminescent device according to claim 8 or 9, characterized in that, including the following steps: sequentially disposing an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer and a cathode on a substrate.

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