A triptycene-fused pyrazine derivative, its preparation method and applications

Abstract

The present invention relates to a triptycene-fused pyrazine derivative represented by formula (1), a preparation method thereof, and an application thereof. The compound has a highly twisted molecular structure, and such molecules have high molecular rigidity, which is beneficial to inhibiting intramolecular and intermolecular vibrational and rotational relaxations and achieving high light efficiency. In addition, it has a small singlet-triplet energy gap (<0.2 eV), so that the triptycene-fused pyrazine derivative of the present invention has thermally activated delayed fluorescence properties. From the aspect of molecular structure packing, the 3D three-dimensional molecular configuration can effectively inhibit intermolecular close packing while ensuring the thermal stability of the molecule, which is beneficial to forming a uniform and stable amorphous film and is suitable for use as an electroluminescent material in OLED devices. Compared with the commercial iridium complex Flrpic, the electroluminescent device prepared using the triptycene-fused pyrazine derivative of the present invention has a higher external quantum efficiency.

Description

Technical Field

[0001] The present invention specifically relates to a triptycene-fused pyrazine derivative, a preparation method thereof and an application thereof, belonging to the technical field of organic optoelectronic material applications. Background Art

[0002] Organic light-emitting diode (OLED) technology has received increasing attention from academia and industry due to its many advantages such as self-luminescence, wide viewing angle, wide color gamut, fast response, light weight, thin thickness, flexibility and foldability. As a key part of OLED devices, highly efficient and stable electroluminescent materials are urgently needed to be developed.

[0003] Luminescent layer materials mainly include three categories: traditional fluorescent materials, phosphorescent materials, and thermally activated delayed fluorescence materials (TADF). Pure organic thermally activated delayed fluorescence materials have the advantages of controllable structure, low cost, and environmental friendliness, and are the third generation of electroluminescent materials after traditional fluorescent materials and phosphorescent materials. However, designing and synthesizing TADF materials with short luminescence lifetimes and high quantum efficiencies remains a technical challenge.

[0004] In addition, factors such as the thermal stability and film-forming property of the luminescent layer affect the stability and working life of OLED devices. High thermal stability can inhibit the decomposition of materials during the preparation of devices by vacuum evaporation, and excellent film-forming properties promote the effective transfer of energy between the luminescent layer and adjacent functional layers, which is beneficial to improving the performance of the devices. Therefore, designing and preparing TADF materials with short lifetimes, high quantum efficiencies, high stability, and excellent film-forming properties is 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 triptycene-fused pyrazine derivative having the structure shown in formula (1):

[0006]

[0007] Wherein: R1, R2, R3, R4 and R1’, R2’, R3’, R4’ are the same or different and are independently selected from H, halogen, cyano, and the following groups which are unsubstituted or optionally substituted by one, two or more Rs: C 1-12 alkyl, C 6-60 aryl, 5-60-membered heteroaryl, -N-(C 6-60 aryl)2;

[0008] The Rs are selected from -N-(C 6-60 aryl)2, C 6-60 aryl, C 1-12 alkyl, or -N-(5-60-membered heteroaryl)2;

[0009] The Rs is further optionally substituted by one, two or more of the following groups: C 1-12 alkyl, cyano;

[0010] A1 and A2 are the same or different and are each independently selected from the groups represented by the following formulas (2)-(6):

[0011]

[0012] wherein # represents the position of the connection point with the linking unit; in formulas (3)-(6) represents forming a ring at the position of the pyrazine ring in the skeleton of formula (1) ;

[0013] D and D' are the same or different and are each independently selected from H, unsubstituted, and the following groups optionally substituted by one, two or more Rs1: C 6-60 aryl, 5-60-membered heteroaryl, cyano, -N-(C 6-60 aryl)2, or -N-(5-60-membered heteroaryl)2, provided that D and D' in formula (6) are not both H;

[0014] Rs1 is selected from the following groups: cyano, C 1-12 alkyl, C 6-60 aryl, -N-(C 6-60 aryl)2, or -N-(5-60-membered heteroaryl)2;

[0015] The Rs1 is further optionally substituted by one, two or more of the following groups: C 1-12 alkyl, cyano.

[0016] According to an embodiment of the present invention, R1, R2, R3, R4 and R1', R2', R3', R4' are the same or different and are each independently selected from H, cyano, C 6-14 aryl, C substituted by N-(C 6-14 aryl)2 6-14 aryl, 5-14-membered heteroaryl, 5-14-membered heteroaryl substituted by C 1-6 alkyl, -N-(5-14-membered heteroaryl)2, -N-(C 6-14 aryl)2, or 5-14-membered heteroaryl substituted by C 6-14 aryl;

[0017] In formula (2), D is selected from H, cyano, C substituted by N-(C 6-14 aryl)2 6-14 aryl, -N-(C 6-14 aryl)2, 5-14-membered heteroaryl substituted by C 1-6 alkyl, 5-14-membered heteroaryl substituted by C 6-14 aryl, C 6-14Aryl, 5- to 14-membered heteroaryl;

[0018] In formula (3), D and D' are the same or different and are independently selected from H, cyano, N-(C 6-14 aryl)2-substituted C 6-14 aryl, -N-(C 6-14 aryl)2, C 1-6 alkyl-substituted 5- to 14-membered heteroaryl, C 6-14 aryl-substituted 5- to 14-membered heteroaryl, C 6-14 aryl, 5- to 14-membered heteroaryl;

[0019] In formula (4), D and D' are the same or different and are independently selected from H, cyano, C 1-6 alkyl-substituted 5- to 14-membered heteroaryl, 5- to 14-membered heteroaryl, C 6-14 aryl-substituted 5- to 14-membered heteroaryl, N-(C 6-14 aryl)2-substituted C 6-14 aryl, -N-(C 6-14 aryl)2, C 6-14 aryl;

[0020] In formula (6), D and D' are the same or different and are independently selected from cyano, N-(C 6-14 aryl)2-substituted C 6-14 aryl, -N-(C 6-14 aryl)2, C 1-6 alkyl-substituted 5- to 14-membered heteroaryl, C 6-14 aryl-substituted 5- to 14-membered heteroaryl, C 6-14 aryl, 5- to 14-membered heteroaryl.

[0021] According to a preferred embodiment of the present invention, the triptycene-fused pyrazine derivative represented by formula (1) is one of the following structures:

[0022]

[0023]

[0024]

[0025]

[0026]

[0027] According to an embodiment of the present invention, the triptycene-fused pyrazine derivative represented by formula (1) is doped in the host material BCPO or CBP at 20 wt% and made into a thin film, having a photoluminescence spectrum as shown in Figure 1 the figure.

[0028] According to an embodiment of the present invention, the triptycene-fused pyrazine derivative shown in formula (1) is doped in the host material BCPO or CBP film at 20 wt%, and has transient decay spectrograms as shown in Figure 2 and 3 shown.

[0029] According to an embodiment of the present invention, the triptycene-fused pyrazine derivative shown in formula (1) has a thermogravimetric analysis curve as shown in Figure 4 shown.

[0030] The present invention also provides a method for preparing the triptycene-fused pyrazine derivative shown in formula (1) above, which includes the following steps: a condensation reaction between a triptycene diamine derivative and an ortho-diketone derivative.

[0031] The present invention also provides the use of the above triptycene-fused pyrazine derivative in the preparation of organic electronic devices, preferably in the preparation of organic electroluminescent devices.

[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 triptycene-fused pyrazine derivative shown in formula (1) above.

[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 triptycene-fused pyrazine derivative shown in formula (1) is located in the light-emitting layer.

[0035] The present invention also provides a method for preparing the organic electroluminescent device, which includes 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 vacuum conditions, for example, under the condition that the vacuum degree is lower than 2×10 -5 Pa, and further preferably, the evaporation rate 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 three-dimensional triptycene-fused pyrazine as the structural center and can be applied to the field of electroluminescence.

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

[0041] (1) By introducing a homoconjugated triptycene skeleton and using triptycene-fused pyrazine 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, achieving high light efficiency. In addition, they have a small singlet-triplet energy gap (<0.2 eV), enabling the triptycene-fused pyrazine derivatives of the present invention to possess thermally activated delayed fluorescence properties. From the perspective of molecular structure packing, the 3D stereomolecular configuration can effectively suppress intermolecular close packing while ensuring the thermal stability of the molecules, facilitating the formation of a uniform and stable amorphous film, and being suitable for use as an electroluminescent material in OLED devices.

[0042] (2) Compared with the commercial iridium complex Flrpic, the electroluminescent device prepared using the triptycene-fused pyrazine derivative of the present invention has a higher external quantum efficiency.

[0043] (3) The preparation process of the triptycene-fused pyrazine derivative of the present invention is simple, and the raw materials used in the synthesis are easily available. Such materials have good application effects in electroluminescent devices and have prospects for industrialization and commercialization.

[0044] Term Definitions and Explanations

[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 represent 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 group is, 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 6-60 aryl" should be understood to mean a monocyclic, bicyclic or tricyclic hydrocarbon ring that is monovalent, aromatic or partially aromatic and has 6 to 60 carbon atoms, preferably "C 6-14 aryl". The term "C 6-14 aryl" should be understood to mean a monocyclic, bicyclic or tricyclic hydrocarbon ring that is monovalent, aromatic or partially aromatic and has 6, 7, 8, 9, 10, 11, 12, 13 or 14 carbon atoms ("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 "5-60 membered heteroaryl" should be understood to include monovalent monocyclic, bicyclic or tricyclic aromatic ring systems having 5 to 60 ring atoms and containing 1-5 heteroatoms independently selected from N, O and S, such as "5-14 membered heteroaryl". The term "5-14 membered heteroaryl" should be understood to include monovalent monocyclic, bicyclic or tricyclic aromatic ring systems 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 1-5, preferably 1-3 heteroatoms independently selected from N, O and S and, additionally, may be benzo-fused in each case. In particular, heteroaryl is selected from thienyl, furyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, thieno-4H-pyrazolyl, etc. and their benzo derivatives, such as benzofuryl, benzothienyl, benzoxazolyl, benzoisoxazolyl, 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 specified, a heterocyclic group, heteroaryl group or heteroarylene group includes all possible isomeric forms thereof, such as its position isomers. Thus, for some illustrative and non-limiting examples, a pyridyl group or pyridylene group includes pyridin-2-yl, pyridylene-2-yl, pyridin-3-yl, pyridylene-3-yl, pyridin-4-yl and pyridylene-4-yl; a thienyl group or thienylene group includes thien-2-yl, thienylene-2-yl, thien-3-yl and thienylene-3-yl. Description of the Drawings

[0050] Figure 1 The steady-state photoluminescence spectra of Compound 1-23 of Example 3 of the present invention as a guest luminescent material doped at 20 wt% in a host material CBP thin film and Compound 1-24 of Example 4 doped at 20 wt% in a host material BCPO thin film.

[0051] Figure 2 The transient decay spectrum (at room temperature) of Compound 1-23 of Example 3 of the present invention as a guest luminescent material doped at 20 wt% in a host material CBP thin film.

[0052] Figure 3 The transient decay spectrum (at room temperature) of Compound 1-24 of Example 4 of the present invention as a guest luminescent material doped at 20 wt% in a host material BCPO thin film.

[0053] Figure 4 The thermogravimetric analysis (TGA) curves of the compounds (Compounds 1-23 and 1-24) of Example 3 and Example 4 of the present invention. The thermal decomposition temperatures of Compounds 1-23 and 1-24 are 549 °C and 537 °C respectively, indicating good thermal stability of the compounds.

[0054] Figure 5 The external quantum efficiency, power efficiency, current efficiency - brightness curves of the organic light-emitting devices of Example 10 and Example 11 of the present invention. It can be known from the curve analysis that the light-emitting efficiency of the organic light-emitting devices corresponding to the compounds prepared in Example 3 and Example 4 is relatively high.

[0055] Figure 6 The structural diagram of an organic light-emitting device using the compound of the present invention.

[0056] Wherein, 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 Description of the Invention

[0057] The technical solution of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only for illustrative explanation 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.

[0058] 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.

[0059] Example 1 Synthesis of Compound 1-1

[0060] [Synthesis of Compound P1]

[0061]

[0062] Compound Q1 (426 mg, 1.5 mmol) and 1-(4-bromophenyl)-2-phenylethane-1,2-dione (435 mg, 1.5 mmol) were successively added to a 100 mL two-necked round-bottom flask, 25 mL of anhydrous n-butanol was added, and the mixture was heated to 120 °C and refluxed overnight under condensation. After cooling to room temperature, 100 mL of deionized water was added and extracted with dichloromethane. The recovered organic phase was washed several times with saturated brine, dried over anhydrous Na2SO4, the solvent was evaporated, and the product was separated and purified by silica gel column chromatography to obtain yellow solid compound P1 (643 mg, yield: 80%).

[0063] MS(EI): m / z 536.09[M + ; Combustion method elemental analysis: C 34 H 21 (%) Calculated value: C 75.98; H 3.94; Measured value: C 75.87, H 3.90.

[0064] [Synthesis of Compound 1-1]

[0065] The synthesis route of Compound 1-1 is shown as follows:

[0066]

[0067] Compound P1 (536 mg, 1 mmol), triphenylamine phenylboronic acid (2.02 g, 1.2 mmol), K2CO3 (347 mg, 9 mmol), and a mixture of THF / H2O (15 mL / 3 mL) were added to a 50 mL two-necked flask. Finally, Pd(PPh3)4 (46 mg, 0.05 mmol) was added, and the mixture was refluxed at 70 °C for 24 h under a N2 atmosphere. After cooling to room temperature, the mixture was extracted with brine and ethyl acetate. The collected organic phase was dried over anhydrous Na2SO4 and concentrated by rotary evaporation. The crude product was separated and purified by silica gel column chromatography to obtain the product compound 1-1 (520 mg, yield: 75%) as a pale blue solid.

[0068] MS(EI): m / z 701.28[M + ; Combustion elemental analysis: C 52 H 35 (%) Calculated: C 88.99; H 5.03; Found: C 88.85, H 4.99.

[0069] Example 2 Synthesis of Compound 1-10

[0070] [Synthesis of Compound P2]

[0071] The synthetic route of Compound P2 is as follows:

[0072]

[0073] Compound Q1 (426 mg, 1.5 mmol) and 1-(4-bromophenyl)-5,6-dibromonaphthalene-1,2-dione (600 mg, 1.5 mmol) were successively added to a 100 mL two-necked round-bottom flask, 25 mL of anhydrous n-butanol was added, and the mixture was heated to 120 °C and refluxed overnight under condensation. After cooling to room temperature, 100 mL of deionized water was added and the mixture was extracted with dichloromethane. The recovered organic phase was washed several times with saturated brine, dried over anhydrous Na2SO4, the solvent was evaporated, and the product was separated and purified by silica gel column chromatography to obtain the yellow solid compound P2 (750 mg, yield: 85%).

[0074] MS(EI): m / z 587.97[M + ; Combustion elemental analysis: C 32 H 16 (%) Calculated: C 65.33; H 2.74; Found: C 65.29, H 2.72.

[0075] [Synthesis of Compound P3]

[0076] The synthetic route of Compound P3 is as follows:

[0077]

[0078] Compound P2 (1.41 g, 2.4 mmol), 9,9-dimethyl-9,10-dihydroacridine (1.0 g, 5.0 mmol), palladium acetate (28 mg, 0.12 mmol), cesium carbonate (3.12 g, 9.6 mmol), tri-tert-butylphosphine tetrafluoroborate (88 mg, 0.3 mmol) were added to a 100 mL double-necked bottle, 40 mL of anhydrous toluene was added, and the mixture was heated to 110°C and condensed and refluxed overnight. After cooling to room temperature, 100 mL of deionized water was added and extracted with dichloromethane, and the recovered organic phase was washed with saturated brine for several times, dried over anhydrous Na2SO4, the solvent was dried, and separated and purified by silica gel column chromatography to obtain yellow solid compound P3 (824 mg, yield: 48%).

[0079] MS (EI): m / z 715.16 [M + ]; Combustion method element analysis: C 47 H 30 (%) Calculated value: C 78.77; H 4.22; Found: C 78.65, H 4.20.

[0080] [Synthesis of Compound 1-10]

[0081] The synthetic route of compound 1-10 is as follows:

[0082]

[0083] After compound P3 (717 mg, 1 mmol) was dissolved in DMF (10 mL), cuprous cyanide (110 mg, 1.2 mmol) was added, and the mixture was heated to 140°C and stirred for 24 hours. After the reaction solution was cooled to room temperature, ammonia water (25%, 20 mL) was added. After the mixture was extracted with dichloromethane several times, the organic phase was dried and purified by column chromatography to obtain white solid compound 1-10 (466 mg, yield: 65%).

[0084] MS (EI): m / z 662.25 [M + ]; Combustion method element analysis: C 48 H 30 (%) Calculated value: C 86.98; H 4.56; Found: C 86.88, H 4.51.

[0085] Example 3 Synthesis of Compound 1-23

[0086] [Synthesis of Compound P4]

[0087] The synthetic route of compound P4 is as follows:

[0088]

[0089] 3,6-dibromo-9,10-phenanthrenequinone (732 mg, 2 mmol), phenoxazine (806 mg, 4.4 mmol), cesium carbonate (2.6 g, 8 mmol), tri-tert-butylphosphine (61 mg, 0.3 mmol), palladium acetate (23 mg, 0.1 mmol) and 70 mL of anhydrous toluene were added to a 200 mL double-necked reaction bottle in sequence, and heated to 110°C for condensation and reflux overnight. After cooling to room temperature, 100 mL of deionized water was added and extracted with dichloromethane, and the recovered organic phase was washed with saturated brine for several times, dried over anhydrous Na2SO4, the solvent was dried, and separated and purified by silica gel column chromatography to obtain a black solid compound P4 (684 mg, yield: 60%).

[0090] MS(EI): m / z 57016[M + ]; Combustion method element analysis: C 38 H 22 (%) Calculated value: C 79.99; H 3.89; Found value: C 79.95, H.385.

[0091] [Synthesis of Compound 1-23]

[0092] The synthetic route of compound 1-23 is as follows:

[0093]

[0094] Compound Q1 (285 mg, 1.0 mmol) and P4 (570 mg, 1.0 mmol) were added to a 100 ml double-necked round-bottom flask in sequence, and 25 mL of anhydrous n-butanol was added, and the mixture was heated to 120°C and refluxed overnight. After cooling to room temperature, 100 mL of deionized water was added and extracted with dichloromethane. The recovered organic phase was washed with saturated brine for several times, dried over anhydrous Na2SO4, the solvent was dried, and separated and purified by silica gel column chromatography to obtain a red solid compound 1-23 (737 mg, yield: 90%).

[0095] MS (EI): m / z 818.27 [M + ]; Combustion method element analysis: C 58 H 34 (%) Calculated value: C 85.07; H 4.18; Found: C 84.99, H 4.15.

[0096] Example 4 Synthesis of Compound 1-24

[0097] [Synthesis of Compound P5]

[0098] The synthetic route of compound P5 is as follows:

[0099]

[0100] 1,2-bis(4-bromophenyl)ethane-1,2-dione (736 mg, 2 mmol), phenoxazine (806 mg, 4.4 mmol), cesium carbonate (2.6 g, 8 mmol), tri-tert-butylphosphine (61 mg, 0.3 mmol), palladium acetate (23 mg, 0.1 mmol) and 70 mL of anhydrous toluene were added to a 200 mL double-necked reaction bottle in sequence, and heated to 110°C for condensation and reflux overnight. After cooling to room temperature, 100 mL of deionized water was added and extracted with dichloromethane, and the recovered organic phase was washed with saturated brine for several times, dried over anhydrous Na2SO4, the solvent was dried, and separated and purified by silica gel column chromatography to obtain a black solid compound P5 (573 mg, yield: 50%).

[0101] MS (EI): m / z 572.17 [M + ]; Combustion method element analysis: C 38 H 24 (%) Calculated value: C 79.71; H 4.22; Found: C 79.68, H 4.19.

[0102] [Synthesis of Compound 1-24]

[0103] The synthetic route of compound 1-24 is as follows:

[0104]

[0105] Compound Q1 (285 mg, 1.0 mmol) and P5 (573 mg, 1.0 mmol) were added to a 100 ml double-necked round-bottom flask in sequence, and 25 mL of anhydrous n-butanol was added, and the mixture was heated to 120°C and refluxed overnight. After cooling to room temperature, 100 mL of deionized water was added and extracted with dichloromethane. The recovered organic phase was washed with saturated brine for several times, dried over anhydrous Na2SO4, the solvent was dried, and separated and purified by silica gel column chromatography to obtain a red solid compound 1-24 (723 mg, yield: 88%).

[0106] MS (EI): m / z 820.28 [M + ]; Combustion method element analysis: C 58 H 36 (%) Calculated value: C 84.86; H 4.42; Found: C 84.90, H 4.45.

[0107] Example 5 Synthesis of Compound 1-30

[0108] [Synthesis of Compound Q2]

[0109] The synthesis route of compound Q2 is as follows:

[0110]

[0111] Compound Q1 (1.42 g, 5 mmol) was dissolved in dry acetonitrile (25 mL) and cooled to 0 °C. At this temperature, N-iodosuccinimide (2.5 g, 11 mmol) and trifluoroacetic acid (0.3 mL) were added thereto in sequence. The mixture was stirred overnight at room temperature. After evaporation of the solvent, dichloromethane, aqueous sodium bicarbonate solution and saturated brine were added. After extraction for several times, the organic phase was dried, evaporated and purified by column chromatography (mobile phase: petroleum ether) to obtain white solid compound Q2 (2.4 g, yield: 91%).

[0112] MS (EI): m / z 535.92 [M + ; Elemental analysis by combustion method: C 20 H 14 (%) Calculated: C 44.80; H 2.63; Found: C 44.78, H 2.65.

[0113] [Synthesis of Compound P6]

[0114] The synthesis route of compound P6 is as follows:

[0115]

[0116] Compound Q2 (536 mg, 1.0 mmol) and benzil (211 mg, 1.0 mmol) were added to a 100 ml two-necked round-bottom flask in sequence. 20 mL of anhydrous n-butanol was added, and the mixture was heated to 120 °C and refluxed overnight with condensation. After cooling to room temperature, 50 mL of deionized water was added and the mixture was extracted with dichloromethane. The recovered organic phase was washed with saturated brine for several times, dried over anhydrous Na2SO4, the solvent was evaporated, and the mixture was separated and purified by silica gel column chromatography to obtain yellow solid compound P6 (625 mg, yield: 88%).

[0117] MS (EI): m / z 709.97 [M + ; Elemental analysis by combustion method: C 34 H 20 (%) Calculated: C 57.49; H 2.84; Found: C 57.46, H 2.82.

[0118] [Synthesis of Compound 1-30]

[0119] The synthesis route of compound 1-30 is as follows:

[0120]

[0121] Compound P6 (1.0 g, 1.5 mmol), copper(I) iodide (57 mg, 0.3 mmol), (1S,2S)-cyclohexane-1,2-diamine (17.2 mg, 0.15 mmol), 9,9-dimethyl-9,10-dihydroacridine (732 mg, 3.5 mmol), and sodium tert-butoxide (290 mg, 3 mmol) were successively added to a 200 mL two-necked round-bottom flask. 45 mL of anhydrous 1,4-dioxane was added, and the mixture was heated to 110 °C and refluxed overnight. After cooling to room temperature, 100 mL of deionized water was added and the mixture was extracted with dichloromethane. The recovered organic phase was washed several times with saturated brine, dried over anhydrous Na2SO4, the solvent was evaporated, and the product was purified by silica gel column chromatography to obtain the yellow solid compound 1-30 (480 mg, yield: 55%).

[0122] MS(EI): m / z 872.39 [M + ; Combustion elemental analysis: C 64 H 48 (%) Calculated: C 88.04; H 5.54; Found: C 88.06, H 5.52.

[0123] Synthesis of Compound 1-34 in Example 6

[0124] [Synthesis of Compound P7]

[0125] The synthetic route of compound P7 is as follows:

[0126]

[0127] Compound Q2 (536 mg, 1.0 mmol) and 1,10-phenanthroline-5,6-dione (210 mg, 1.0 mmol) were successively added to a 100 mL two-necked round-bottom flask. 20 mL of anhydrous n-butanol was added, and the mixture was heated to 120 °C and refluxed overnight. After cooling to room temperature, 50 mL of deionized water was added and the mixture was extracted with dichloromethane. The recovered organic phase was washed several times with saturated brine, dried over anhydrous Na2SO4, the solvent was evaporated, and the product was purified by silica gel column chromatography to obtain the yellow solid compound P7 (582 mg, yield: 82%)

[0128] MS(EI): m / z 709.95 [M + ; Combustion elemental analysis: C 32 H 16 (%) Calculated: C 54.11; H 2.27; Found: C 54.09, H 2.24.

[0129] [Synthesis of Compounds 1-34]

[0130] The synthetic route of Compounds 1-34 is as follows:

[0131]

[0132] Compound P7 (1.27 g, 1.8 mmol), copper(I) iodide (70 mg, 0.36 mmol), (1S,2S)-cyclohexane-1,2-diamine (21 mg, 0.15 mmol), phenoxazine (733 mg, 4.0 mmol), and sodium tert-butoxide (346 mg, 3.6 mmol) were successively added to a 200 mL two-necked round-bottom flask. 45 mL of anhydrous 1,4-dioxane was added, and the mixture was heated to 110 °C and refluxed overnight under condensation. After cooling to room temperature, 100 mL of deionized water was added and the mixture was extracted with dichloromethane. The recovered organic phase was washed several times with saturated brine, dried over anhydrous Na2SO4, the solvent was evaporated, and the product was separated and purified by silica gel column chromatography to obtain red solid Compound 1-34 (813 mg, yield: 55%).

[0133] MS (EI): m / z 820.26 [M + ; Combustion elemental analysis: C 56 H 32 (%) Calculated: C 81.94; H 3.93; Found: C 81.95, H 3.90.

[0134] Synthesis of Compound 1-39 in Example 7

[0135] [Synthesis of Compound Q3]

[0136] The synthetic route of Compound Q3 is as follows:

[0137]

[0138] Compound Q2 (536 mg, 1.0 mmol) and 1,2-bis(4-bromophenyl)ethane-1,2-dione (366 mg, 1.0 mmol) were successively added to a 100 mL two-necked round-bottom flask. 20 mL of anhydrous n-butanol was added, and the mixture was heated to 120 °C and refluxed overnight under condensation. After cooling to room temperature, 50 mL of deionized water was added and the mixture was extracted with dichloromethane. The recovered organic phase was washed several times with saturated brine, dried over anhydrous Na2SO4, the solvent was evaporated, and the product was separated and purified by silica gel column chromatography to obtain yellow solid Compound Q3 (736 mg, yield: 85%). MS (EI): m / z 867.79 [M + ; Combustion elemental analysis: C 34 H 18(%) Calculated values: C 47.04; H 2.09; Measured values: C 47.01, H 2.14.

[0139] [Synthesis of Compound P8]

[0140] The synthesis route of compound P8 is as follows:

[0141]

[0142] Compound Q3 (1.56 g, 1.8 mmol), copper(I) iodide (70 mg, 0.36 mmol), (1S,2S)-cyclohexane-1,2-diamine (21 mg, 0.15 mmol), 9,9-diphenyl-9,10-dihydroacridine (1.33 g, 4.0 mmol), and sodium tert-butoxide (346 mg, 3.6 mmol) were successively added to a 200 mL two-necked round-bottom flask. 45 mL of anhydrous 1,4-dioxane was added, and the mixture was heated to 110 °C and refluxed overnight under condensation. After cooling to room temperature, 100 mL of deionized water was added and the mixture was extracted with dichloromethane. The recovered organic phase was washed several times with saturated brine, dried over anhydrous Na2SO4, the solvent was evaporated, and the product was separated and purified by silica gel column chromatography to obtain red solid compound P8 (1.37 g, yield: 50%).

[0143] MS(EI): m / z 1278.27 [M + ; Combustion elemental analysis: C 84 H 54 (%) Calculated values: C 78.87; H 4.26; Measured values: C 78.92, H 4.28.

[0144] [Synthesis of Compound 1-39]

[0145] The synthesis route of compound 1-39 is as follows:

[0146]

[0147] Compound P8 (1.28 g, 1 mmol) was dissolved in DMF (10 mL), and then copper(I) cyanide (110 mg, 1.2 mmol) was added. The mixture was heated to 140 °C and stirred for 24 hours. After the reaction solution was cooled to room temperature, ammonia water (25%, 20 mL) was added. The mixture was extracted with dichloromethane several times, the organic phase was evaporated, and the product was purified by column chromatography to obtain yellow solid compound 1-39 (702 mg, yield: 60%).

[0148] MS(EI): m / z 1170.44 [M + ; Combustion elemental analysis: C 86 H 54(%) Calculated values: C 88.18; H 4.65; Measured values: C 88.22, H 4.62.

[0149] Synthesis of Compound 1-43 in Example 8

[0150] [Synthesis of Compound Q4]

[0151] The synthetic route of Compound Q4 is as follows:

[0152]

[0153] Compound Q2 (536 mg, 1.0 mmol) and 3,6-dibromo-9,10-phenanthrenequinone (366 mg, 1.0 mmol) were successively added into a 100 mL two-necked round-bottom flask, 20 mL of anhydrous n-butanol was added, and the mixture was heated to 120 °C and refluxed overnight under condensation. After cooling to room temperature, 50 mL of deionized water was added and extracted with dichloromethane. The recovered organic phase was washed several times with saturated brine, dried over anhydrous Na2SO4, the solvent was evaporated, and the product was separated and purified by silica gel column chromatography to obtain yellow solid Compound Q4 (693 mg, yield: 80%).

[0154] MS(EI): m / z 865.77[M + ; Elemental analysis by combustion method: C 34 H 16 (%) Calculated values: C 47.15; H 1.86; Measured values: C 47.12, H 1.90.

[0155] [Synthesis of Compound P9]

[0156] The synthetic route of Compound P9 is as follows:

[0157]

[0158] Compound Q4 (1.56 g, 1.8 mmol), copper(I) iodide (70 mg, 0.36 mmol), (1S,2S)-cyclohexane-1,2-diamine (21 mg, 0.15 mmol), 9,9-diphenyl-9,10-dihydroacridine (1.33 g, 4.0 mmol), and sodium tert-butoxide (346 mg, 3.6 mmol) were successively added into a 200 ml two-necked round-bottom flask, 45 mL of anhydrous 1,4-dioxane was added, and the mixture was heated to 110 °C and refluxed overnight under condensation. After cooling to room temperature, 100 mL of deionized water was added and extracted with dichloromethane. The recovered organic phase was washed several times with saturated brine, dried over anhydrous Na2SO4, the solvent was evaporated, and the product was separated and purified by silica gel column chromatography to obtain red solid Compound P9 (1.1 g, yield: 50%).

[0159] MS (EI): m / z 1276.25 [M + ]; Combustion method element analysis: C 84 H 52 (%) Calculated value: C 79.00; H 4.10; Found: C 78.98, H 4.08.

[0160] [Synthesis of Compound 1-43]

[0161] The synthetic route of compound 1-43 is as follows:

[0162]

[0163] After compound P9 (637 mg, 0.5 mmol) was dissolved in DMF (10 mL), cuprous cyanide (71 mg, 0.8 mmol) was added, and the mixture was heated to 140°C and stirred for 24 hours. After the reaction solution was cooled to room temperature, ammonia water (25%, 20 mL) was added. After the mixture was extracted with dichloromethane several times, the organic phase was dried and purified by column chromatography to obtain yellow solid compound 1-43 (380 mg, yield: 65%).

[0164] MS (EI): m / z 1168.43 [M + ]; Combustion method element analysis: C 86 H 52 (%) Calculated value: C 88.33; H 4.48; Found: C 88.30, H 4.52.

[0165] Example 9 Synthesis of Compound 1-51

[0166] [Synthesis of Compound P10]

[0167] The synthetic route of compound P10 is as follows:

[0168]

[0169] Compound Q3 (1.73 g, 2 mmol), 9,9-dimethyl-9,10-dihydroacridine (921 mg, 4.4 mmol), cesium carbonate (2.6 g, 8 mmol), tri-tert-butylphosphine (61 mg, 0.3 mmol), palladium acetate (23 mg, 0.1 mmol) and 70 mL of anhydrous toluene were added to a 200 mL double-necked reaction bottle in sequence, and heated to 110°C for condensation and reflux overnight. After cooling to room temperature, 100 mL of deionized water was added and extracted with dichloromethane, and the recovered organic phase was washed with saturated brine for several times, dried over anhydrous Na2SO4, the solvent was dried, and separated and purified by silica gel column chromatography to obtain a black solid compound P10 (1.1 g, yield: 50%).

[0170] MS (EI): m / z 1124.18 [M + ; Combustion elemental analysis: C 64 H 46 (%) Calculated values: C 68.33; H 4.12; Measured values: C 68.30, H 4.10.

[0171] [Synthesis of Compound 1-51]

[0172] The synthesis route of Compound 1-51 is as follows:

[0173]

[0174] Compound P10 (1.1 g, 1 mmol), 3-pyridineboronic acid (148 mg, 1.2 mmol), K2CO3 (347 mg, 9 mmol), and THF / H2O (15 mL / 3 mL) solvent were added to a 50 mL two-necked flask. Finally, Pd(PPh3)4 (46 mg, 0.05 mmol) was added, and the mixture was refluxed at 70 °C for 24 h under a N2 atmosphere. After cooling to room temperature, the mixture was extracted with brine and ethyl acetate. The collected organic phase was dried over anhydrous Na2SO4 and concentrated by rotary evaporation. The crude product was separated and purified by silica gel column chromatography to obtain Compound 1-51 as a pale blue solid (718 mg, yield: 70%).

[0175] MS (EI): m / z 1024.43 [M + ; Combustion elemental analysis: C 74 H 52 (%) Calculated values: C 86.69; H 5.11; Measured values: C 86.72, H 5.13.

[0176] Preparation of Organic Electroluminescent Device 1 (OLED-1) in Example 10

[0177] In this example, Compound 1-23 prepared in Example 3 was used as the doped luminescent material, indium tin oxide (ITO) as the anode, commercial compound CBP as the host material, HAT-CN as the hole injection material, TAPC as the hole transport material, TCTA as the electron 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 / CBP:Compound 1-23 (20 wt%) / B3PYMPM / Liq / Al.

[0178] 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 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 onto the glass substrate to 10 nm as the hole injection layer; subsequently, evaporate TAPC at a rate of 0.2 nm / s to 45 nm as the hole transport layer; then, evaporate TCTA at a rate of 0.2 nm / s to 5 nm as the electron blocking layer; then, co-evaporate the host material CBP and compound 1-23 from two sources at a rate of 0.2 nm / s to 20 nm as the light-emitting layer; then, evaporate B3PYMPM at a rate of 0.2 nm / s to 45 nm as the electron transport layer; then, evaporate Liq at a rate of 0.02 nm / s to 1 nm as the electron injection layer; finally, evaporate Al at a rate of 0.5 nm / s to 100 nm as the cathode. The structure of the organic electroluminescent device is as Figure 6 shown.

[0179] Preparation of Organic Electroluminescent Device 2 (OLED-2) in Example 11

[0180] In this example, compound 1-24 prepared in Example 4 is used as the doped light-emitting material, indium tin oxide (ITO) as the anode, commercial compound BCPO as the host material, HAT-CN as the hole injection material, TAPC as the hole transport material, mCP as the electron blocking material, DPEPO as the hole blocking material, TmPyPB as the electron transport material, LiF as the electron injection material, and metal aluminum (Al) as the cathode material. The device structure is: ITO / HAT-CN / TAPC / mCP / BCPO: compound 1-24 (20 wt%) / DPEPO / TmPyPB / LiF / Al. The structure of the organic electroluminescent device is as Figure 6 shown.

[0181] 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 treated ITO in the chamber of the vacuum evaporation device, evacuate to below 2×10-5 After reaching 10 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 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; then, mCP is evaporated at a deposition rate of 0.2 nm / s to 10 nm as the electron blocking layer; then, the host material BCPO and compound 1-24 are co-evaporated from two sources at a deposition rate of 0.2 nm / s to 20 nm as the light-emitting layer; then, DPEPO is evaporated at a deposition rate of 0.2 nm / s to 5 nm as the hole blocking layer; then, TmPyPB is evaporated at a deposition rate of 0.2 nm / s to 30 nm as the electron transport layer; then, LiF 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.

[0182] Preparation of Organic Light-Emitting Device 3 (OLED-3) in Example 12

[0183] OLED-3 was prepared under the same production conditions as OLED-2, except that compound 1-6 was used as the light-emitting layer material instead of compound 1-24.

[0184] Device Preparation of Comparative Example A (OLED-A) and Comparative Example B (OLED-B): Except that the commercial iridium complex Flrpic (whose structure is shown below) was used as the light-emitting material instead of compound 1-23 or 1-24 in the devices prepared in Example 10 and Example 11, respectively, other operations and preparation conditions were the same as those in Example 10 and Example 11. The structure of the organic light-emitting device is as Figure 6 shown.

[0185] The structures of the functional layer materials used in Example 10, 11, 12 and Comparative Example A, B are as follows:

[0186]

[0187] Table 1. Comparison of OLED Device Performance in Example 10 - 12 and Comparative Example A, B

[0188] OLED Device Name Host Material Emitting Layer Material External Quantum Efficiency OLED-1 (Example 10) CBP Compound 1-23 14.0％ OLED-2 (Example 11) BCPO Compound 1-24 25.1％ OLED-3 (Example 12) BCPO Compound 1-6 14.8％ OLED-A (Comparative Example A) CBP Flrpic 7.1％ OLED-B (Comparative Example B) BCPO Flrpic 13.0％

[0189] Analysis of the device characterization test results shows that: For the OLED devices prepared with the compounds 1-23, 1-24 and 1-6 of the present invention as the light-emitting layer materials, compared with the OLED devices prepared with the commercial iridium complex Flrpic, the external quantum efficiency shows a significant improvement.

[0190] Test Example 1

[0191] The steady-state photoluminescence spectra of Compound 1-23 of Example 3 of the present invention as a guest luminescent material doped at a concentration of 20% (20 wt%) in the host material CBP thin film and Compound 1-24 of Example 4 doped at a concentration of 20% (20 wt%) in the host material BCPO thin film are as follows Figure 1 shown. It can be seen from Figure 1 that both compounds have efficient green to orange-red light emission in the doped thin films.

[0192] The transient decay spectrum of Compound 1-23 of Example 3 of the present invention as a guest luminescent material doped at a concentration of 20% (20 wt%) in the host material CBP thin film is as follows Figure 2 shown (at room temperature). It can be seen from Figure 2 that Compound 1-23 is a thermally activated delayed fluorescence material.

[0193] The transient decay spectrum of Compound 1-24 of Example 4 of the present invention as a guest luminescent material doped at a concentration of 20% (20 wt%) in the host material BCPO thin film is as follows Figure 3 shown (at room temperature). It can be seen from Figure 3 that this material is a thermally activated delayed fluorescence material.

[0194] The thermogravimetric analysis (TGA) curves of the compounds (Compounds 1-23 and 1-24) of Example 3 and Example 4 of the present invention are as follows Figure 4 shown. It can be seen from Figure 4 that the thermal decomposition temperatures of Compounds 1-23 and 1-24 are 549 °C and 537 °C respectively, indicating that the compounds have good thermal stability.

[0195] The external quantum efficiency, power efficiency, and current efficiency-luminance curves of the organic electroluminescent devices of Example 10 and Example 11 of the present invention are as follows Figure 5 shown. It can be analyzed from the curves that the electroluminescent devices corresponding to the compounds prepared in Example 3 and Example 4 have higher luminous efficiency.

[0196] 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 triphenylene-fused pyrazine derivative shown in formula (1), Wherein: R1, R2, R3, R4, R1’, R2’, R3’, R4’ are selected from H; A1 and A2 are the same and are selected from the groups shown in formula (2) or formula (3) below: where # represents the position of the connection point with the connection unit; in formula (3), represents forming a ring at the position of the pyrazine ring in the backbone of formula (1); In formula (2), D is selected from C 1-6 alkyl-substituted 5- to 14-membered heteroaryl, C 6-14 aryl-substituted 5- to 14-membered heteroaryl, 5- to 14-membered heteroaryl; In formula (3), D and D' are the same and are selected from C 1-6 alkyl-substituted 5- to 14-membered heteroaryl, C 6-14 aryl-substituted 5- to 14-membered heteroaryl, 5- to 14-membered heteroaryl.

2. The triptycene-fused pyrazine derivative according to claim 1, wherein The triphenylene-fused pyrazine derivative shown in formula (1) is one of the following structures:

3. Use of the triphenylene-fused pyrazine derivative according to claim 1 or 2 in the preparation of an organic electronic device; The triphenylene-fused pyrazine derivative is used as a thermally activated delayed fluorescence material.

4. The use according to claim 3, characterized in that, The organic electronic device is an organic light-emitting device.

5. 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 triphenylene-fused pyrazine derivative according to claim 1 or 2; The triphenylene-fused pyrazine derivative is used as a thermally activated delayed fluorescence material.

6. The organic electroluminescent device according to claim 5, characterized in that, 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.

7. The organic electroluminescent device according to claim 6, characterized in that, The triphenylene-fused pyrazine derivative is located in the light-emitting layer.

8. The method for preparing an organic electroluminescent device according to claim 6 or 7, characterized in that, It includes 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.

9. The preparation method according to claim 8, characterized in that, 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 printing.

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