Boron-containing fused ring carbene iridium and platinum complex as well as preparation method and application thereof

Abstract

The invention discloses a boron-containing fused ring carbene iridium and platinum complex, a preparation method thereof, and an application of the complex in preparation of organic electronic devices, especially in organic light emitting diodes. The invention also relates to an organic electronic device containing the boron-containing fused ring carbene iridium and platinum complex, in particular to an organic light-emitting diode, and application of the organic electronic device in display and illumination technologies. By optimizing the structure of the device and changing the concentration of the boron-containing fused ring carbene iridium and platinum complex in a matrix, the optimal device performance can be achieved, an OLED device with high efficiency, high brightness and high stability can be conveniently realized, and a better material option is provided for full-color display and illumination application.

Description

Technical Field

[0001] The invention belongs to the technical field of new materials, and specifically relates to a boron-containing fused-ring carbene iridium and platinum complex, a preparation method and application thereof, and especially relates to application in organic light-emitting diodes. Background Art

[0002] Organic light-emitting diodes (OLEDs) have great potential in the application of optoelectronic devices (such as flat panel displays and lighting) due to the diversity of organic semiconductor materials in synthesis, relatively low manufacturing costs, and excellent optical and electrical properties. In order to improve the luminous efficiency of organic light-emitting diodes, various fluorescent and phosphorescent luminescent material systems have been developed. Organic light-emitting diodes using fluorescent materials have the characteristics of high reliability, but their internal electroluminescence quantum efficiency is limited to 25% under electric field excitation, because the probability ratio of excitons to singlet excited states and triplet excited states is 1:3. In 1999, Professor Thomson of the University of Southern California and Professor Forrest of Princeton University doped tris(2-phenylpyridine)iridium Ir(ppy)3 into N,N-dicarbazole biphenyl (CBP) and successfully prepared green electrophosphorescent devices, which aroused people's strong interest in complex phosphorescent materials. Due to the introduction of heavy metals, the molecular spin-orbit coupling is improved, the phosphorescence lifetime is shortened, and the intersystem crossing of molecules is enhanced, so that phosphorescence can be emitted smoothly. To date, the internal quantum efficiency of phosphorescent OLEDs has been close to 100%.

[0003] Nevertheless, most phosphorescent iridium and platinum complex materials still have too wide emission peak half-width, and some phosphorescent iridium and platinum complexes are also accompanied by low luminous efficiency and poor stability, which to a certain extent affect the luminescent properties of the complex. At present, carbene ligands with strong field effect can solve the problems of stability and luminous efficiency of phosphorescent complexes to a certain extent. At the same time, rigid boron-containing fused ring units can also reduce the emission half-width of phosphorescent complexes to a certain extent. Therefore, in order to further improve the luminescent properties of phosphorescent iridium and platinum complexes and broaden the selection range of such materials, materials based on boron-containing fused ring carbene iridium and platinum complexes are urgently needed to be developed. Summary of the invention

[0004] Purpose of the invention: In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a new type of boron-containing fused-ring carbene iridium and platinum complexes with high stability and strong luminescence efficiency.

[0005] The technical problem that the present invention needs to solve is to provide a method for preparing the boron-containing fused-ring carbene iridium and platinum complex.

[0006] The technical problem that the present invention needs to solve is to provide an application of boron-containing fused-ring carbene iridium and platinum complexes in the preparation of organic electronic devices.

[0007] The final technical problem to be solved by the present invention is to provide an OLED device with high efficiency, high brightness and high stability.

[0008] Technical solution: In order to solve the above technical problems, the present invention provides a boron-containing fused ring carbene iridium and platinum complex, the general formula of which is shown in the structure (AH):

[0009]

[0010] Wherein, X is an O atom or an S atom, and R is a H atom or a tert-butyl group.

[0011] Among them, the boron-containing fused-ring carbene iridium and platinum complexes M1-M40:

[0012]

[0013]

[0014]

[0015]

[0016] The present invention also includes a method for preparing the boron-containing fused-ring carbene iridium and platinum complex, comprising the following steps:

[0017] 1) First, 2,5-dibromo-1,3-difluorobenzene is used as a raw material to undergo a fluorine substitution reaction with phenol and its derivatives or thiophenol and its derivatives in an alkaline high temperature environment to obtain the first step precursor (1a-4a), and then the first step precursor (1b-8b) is obtained by Ullmann reaction with imidazole or benzimidazole in the presence of alkali and cuprous iodide;

[0018] 2) The precursor (1b-8b) prepared in step 1) is further subjected to the anhydrous, oxygen-free and low-temperature conditions to remove the bromine atom in a dry m-xylene solution using n-butyl lithium n-BuLi, and then boron tribromide is added for stirring reaction. Finally, in an alkaline environment of N,N-diisopropylethylamine, by controlling the reaction temperature and time, a series of boron-containing fused ring intermediate compounds (1c-8c) can be obtained, and then methyl iodide is used for methylation reaction to form a series of novel boron-containing fused ring imidazole salts or benzimidazole salt ligands (1d-8d);

[0019] 3) Finally, the boron-containing fused-ring imidazole salt or benzimidazole salt ligand (1d-8d) prepared in step 2) is used to carry out coordination reaction with metal iridium and platinum respectively to obtain a series of boron-containing fused-ring carbene iridium and platinum complexes.

[0020] The present invention also includes the use of the boron-containing fused-ring carbene iridium and platinum complex in the preparation of organic electronic devices.

[0021] Among them, the organic electronic devices are organic light emitting diodes (OLEDs), organic photovoltaic cells (OPVs), organic light emitting cells (OLEECs), organic field effect transistors (OFETs), organic light emitting field effect transistors, organic lasers, organic spin electronic devices, organic sensors and organic plasmon emitting diodes (Organic Plasmon Emitting Diodes).

[0022] The mass concentration of the boron-containing fused-ring carbene iridium and platinum complex in the matrix is ​​1-15wt%.

[0023] The present invention also includes an organic electronic device, which comprises the boron-containing fused-ring carbene iridium and platinum complex.

[0024] Wherein, the mass concentration of the boron-containing fused-ring carbene iridium and platinum complex is 1-15wt%.

[0025] Beneficial effects: Compared with the prior art, the present invention has the following advantages: the ligands contained in the novel phosphorescent iridium and platinum complexes prepared by the present invention have, on the one hand, a carbene coordination unit with a strong field effect, thereby effectively improving the stability and luminescence efficiency of the compound, and on the other hand, a rigid boron-containing fused ring unit, which can further reduce the emission half-peak width of the complex, thereby improving the luminescence performance and the performance of the corresponding device. The present invention also relates to organic electronic devices, especially organic light-emitting diodes, comprising the boron-containing fused ring carbene iridium and platinum complexes according to the present invention, and their applications in display and lighting technology. By optimizing the device structure and changing the concentration of the boron-containing fused ring carbene iridium and platinum complexes in the matrix, the best device performance can be achieved, which facilitates the realization of high-efficiency, high-brightness, and high-stability OLED devices, and provides better material options for full-color display and lighting applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 X-ray single crystal structure of boron-containing fused-ring carbene iridium complex M5;

[0027] Figure 2 X-ray single crystal structure of boron-containing fused-ring carbene iridium complex M9;

[0028] Figure 3 X-ray single crystal structure of boron-containing fused-ring carbene iridium complex M13;

[0029] Figure 4 X-ray single crystal structure of boron-containing fused-ring carbene iridium complex M17;

[0030] Figure 5X-ray single crystal structure of boron-containing fused-ring carbene iridium complex M21. DETAILED DESCRIPTION

[0031] Example 1 Synthesis of Boron-Containing Condensed Ring Carbene Iridium Complex M1

[0032] Synthesis route of boron-containing fused-ring carbene iridium complex M1:

[0033]

[0034] 1. Synthesis of intermediate 1a:

[0035] Place phenol (10.39 g, 110.53 mmol), 2,5-dibromo-1,3-difluorobenzene (9.97 g, 36.80 mmol) and potassium carbonate (15.30 g, 110.70 mmol) in a dry two-necked bottle, evacuate and fill with nitrogen for three cycles, and add N-methylpyrrolidone (NMP) (55 mL) under nitrogen flow. Stir the reaction at 170°C for 24 hours. After cooling to room temperature, remove the NMP solvent by rotary evaporation, add a large amount of water, and extract with ethyl acetate three times. Combine the organic phases and concentrate, and purify them on a silica gel column with dichloromethane: petroleum ether = 1:10 to obtain 13.22 g of white solid, which is intermediate 1a, with a yield of 86%. MALDI-TOF-MS (m / z) 421.1 ([M+1] + ).

[0036] 2. Synthesis of intermediate 1b:

[0037] Place intermediate 1a (5.0 g, 11.9 mmol), imidazole (1.44 g, 21.2 mmol), CuI (1.0 g, 5.25 mmol), potassium carbonate (3.0 g, 21.7 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 70 mL of dry DMF under nitrogen flow, and stir at 150 ° C for 12 hours. Cool to room temperature, evaporate DMF under reduced pressure, then add a large amount of water, extract with dichloromethane three times, combine the organic phases, concentrate, and then pass through a silica gel column with ethyl acetate: petroleum ether = 1:1 to obtain 2.42 g of a white solid, which is intermediate 1b, with a yield of 50%. MALDI-TOF-MS (m / z): 408.3 ([M+1] + ).

[0038] 3. Synthesis of intermediate 1c:

[0039] Intermediate 1b (1.19 g, 2.92 mmol) was added to a dry 100 mL Schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and it was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, the mixture was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, followed by addition of a large amount of water and dichloromethane solution, and then extracted three times. The combined organic phase was concentrated by rotary evaporation and dried to obtain about 0.83 g of a light yellow solid, which was intermediate 1c, with a yield of 85%. MALDI-TOF-MS (m / z): 337.2 ([M+1] + ).

[0040] 4. Synthesis of intermediate 1d:

[0041] Place intermediate 1c (0.67 g, 2 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 20 mL of dry tetrahydrofuran under nitrogen flow, stir at room temperature for ten minutes, then add iodomethane (0.50 mL, 8 mmol), heat to 65 ° C and stir for three days. After the reaction is completed, cool to room temperature, filter and take the filter cake, rinse the filter cake with tetrahydrofuran, and obtain 0.38 g of white solid, which is intermediate 1d, with a yield of 40%. ESI-MS (m / z): 351.3 ([MI] + ).

[0042] 5. Synthesis of boron-containing fused-ring carbene iridium complex M1:

[0043] Place intermediate 1d (0.136 g, 0.285 mmol), Ag2O (0.066 g, 0.285 mmol), [Ir(COD)Cl]2 (0.039 g, 0.057 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add triethylamine (0.04 mL, 0.285 mmol) and chlorobenzene (20 mL) under nitrogen flow, and stir at 120°C for 24 hours. Cool to room temperature, evaporate the solvent under reduced pressure, and then pass through a silica gel column with dichloromethane: petroleum ether = 1:1 to obtain 42 mg of yellow solid, which is the boron-containing fused ring carbene iridium complex M1, with a yield of 30%. MALDI-TOF-MS (m / z): 1239.5 ([M] + ).

[0044] Example 2 Synthesis of Boron-Containing Condensed Ring Carbene Iridium Complex M2

[0045] Synthesis route of boron-containing fused-ring carbene iridium complex M2:

[0046]

[0047] 1. Synthesis of intermediate 2a:

[0048] Place p-tert-butylphenol (16.58 g, 110.53 mmol), 2,5-dibromo-1,3-difluorobenzene (9.97 g, 36.80 mmol) and potassium carbonate (15.30 g, 110.70 mmol) in a dry two-necked bottle, evacuate and fill with nitrogen for three cycles, and add N-methylpyrrolidone (NMP) (55 mL) under nitrogen flow. Stir the reaction at 170°C for 24 hours. After cooling to room temperature, remove the NMP solvent by rotary evaporation, add a large amount of water, and extract with ethyl acetate three times. Combine the organic phases and concentrate, and purify them on a silica gel column with dichloromethane: petroleum ether = 1:10 to obtain 15.66 g of white solid, which is intermediate 2a, with a yield of 80%. MALDI-TOF-MS (m / z): 532.4 ([M] + ).

[0049] 2. Synthesis of intermediate 2b:

[0050] Place intermediate 2a (6.3 g, 11.9 mmol), imidazole (1.44 g, 21.2 mmol), CuI (1.0 g, 5.25 mmol), potassium carbonate (3.0 g, 21.7 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 70 mL of dry DMF under nitrogen flow, and stir at 150 ° C for 12 hours. Cool to room temperature, evaporate DMF under reduced pressure, then add a large amount of water, extract with dichloromethane three times, combine the organic phases, concentrate, and then pass through a silica gel column with ethyl acetate: petroleum ether = 1:1 to obtain 2.78 g of white solid, which is intermediate 2b, with a yield of 45%. MALDI-TOF-MS (m / z): 520.3 ([M+1] + ).

[0051] 3. Synthesis of intermediate 2c:

[0052] Intermediate 2b (1.52 g, 2.92 mmol) was added to a dry 100 mL Schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and the temperature was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, it was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, and then extracted several times with water and dichloromethane. The combined organic phase was concentrated by rotary evaporation and dried to obtain about 1.05 g of a light yellow solid, which was intermediate 2c, with a yield of 80%. MALDI-TOF-MS (m / z): 449.2 ([M+1] + ).

[0053] 4. Synthesis of intermediate 2d:

[0054] Place intermediate 2c (0.90 g, 2 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 20 mL of dry tetrahydrofuran under nitrogen flow, stir at room temperature for ten minutes, then add iodomethane (0.50 mL, 8 mmol), heat to 65 ° C and stir for three days. After the reaction is completed, cool to room temperature, filter and take the filter cake, rinse the filter cake with tetrahydrofuran, and obtain 0.49 g of white solid, which is intermediate 2d, with a yield of 42%. ESI-MS (m / z): 463.2 ([MI] + ).

[0055] 5. Synthesis of boron-containing fused-ring carbene iridium complex M2:

[0056] Place 2d (0.168 g, 0.285 mmol), Ag2O (0.066 g, 0.285 mmol), [Ir(COD)Cl]2 (0.039 g, 0.057 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add triethylamine (0.04 mL, 0.285 mmol) and chlorobenzene (20 mL) under nitrogen flow, and stir at 120 ° C for 24 hours. Cool to room temperature, evaporate the solvent under reduced pressure, and then pass through a silica gel column with dichloromethane: petroleum ether = 1:1 to obtain 45 mg of yellow solid, which is the boron-containing fused ring carbene iridium complex M2, with a yield of 25%. MALDI-TOF-MS (m / z): 1576.5 ([M] + ).

[0057] Example 3 Synthesis of Boron-Containing Condensed Ring Carbene Iridium Complex M3

[0058] Synthesis route of boron-containing fused-ring carbene iridium complex M3:

[0059]

[0060] 1. Synthesis of intermediate 3a:

[0061] Sodium thiophenolate (14.59 g, 110.53 mmol) and 2,5-dibromo-1,3-difluorobenzene (9.97 g, 36.80 mmol) were placed in a dry two-necked bottle, and the vacuum was evacuated and nitrogen was filled for three cycles. N-methylpyrrolidone (NMP) (55 mL) was added under nitrogen flow. The reaction was stirred at 170°C for 24 hours. After cooling to room temperature, the NMP solvent was removed by rotary evaporation, a large amount of water was added, and the mixture was extracted with ethyl acetate three times. The organic phases were combined and concentrated, and purified by silica gel column with dichloromethane: petroleum ether = 1:10 to obtain 13.81 g of white solid, which was intermediate 3a, with a yield of 83%. MALDI-TOF-MS (m / z): 452.2 ([M] + ).

[0062] 2. Synthesis of intermediate 3b:

[0063] Place intermediate 3a (5.38 g, 11.9 mmol), imidazole (1.44 g, 21.2 mmol), CuI (1.0 g, 5.25 mmol), potassium carbonate (3.0 g, 21.7 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 70 mL of dry DMF under nitrogen flow, and stir at 150 ° C for 12 hours. Cool to room temperature, evaporate DMF under reduced pressure, then add a large amount of water, extract with dichloromethane three times, combine the organic phases, concentrate, and then pass through a silica gel column with ethyl acetate: petroleum ether = 1:1 to obtain 2.19 g of yellow solid, which is intermediate 3b, with a yield of 42%. MALDI-TOF-MS (m / z): 440.1 ([M+1] + ).

[0064] 3. Synthesis of intermediate 3c:

[0065] Intermediate 3b (1.28 g, 2.92 mmol) was added to a dry 100 mL Schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and the temperature was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, it was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, and then extracted several times with water and dichloromethane. The combined organic phase was concentrated by rotary evaporation and dried to obtain about 0.91 g of yellow solid, which was intermediate 3c, with a yield of 85%. MALDI-TOF-MS (m / z): 369.3 ([M+1] + ).

[0066] 4. Synthesis of intermediate 3d:

[0067] Place intermediate 3c (0.74 g, 2 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 20 mL of dry tetrahydrofuran under nitrogen flow, stir at room temperature for ten minutes, then add iodomethane (0.50 mL, 8 mmol), heat to 65 ° C and stir for three days. After the reaction is completed, cool to room temperature, filter the filter cake, and rinse the filter cake with tetrahydrofuran to obtain 0.46 g of yellow solid, which is intermediate 3d, with a yield of 45%. ESI-MS (m / z): 383.3 ([MI] + ).

[0068] 5. Synthesis of boron-containing fused-ring carbene iridium complex M3:

[0069] Place intermediate 3d (0.145 g, 0.285 mmol), Ag2O (0.066 g, 0.285 mmol), [Ir(COD)Cl]2 (0.039 g, 0.057 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add triethylamine (0.04 mL, 0.285 mmol) and chlorobenzene (20 mL) under nitrogen flow, and stir at 120 ° C for 24 hours. Cool to room temperature, evaporate the solvent under reduced pressure, and then pass through a silica gel column with dichloromethane: petroleum ether = 1:1 to obtain 35 mg of yellow solid, which is the boron-containing fused ring carbene iridium complex M3, with a yield of 23%. MALDI-TOF-MS (m / z): 1336.3 ([M] + ).

[0070] Example 4 Synthesis of Boron-Containing Condensed Ring Carbene Iridium Complex M4

[0071] Synthesis route of boron-containing fused-ring carbene iridium complex M4:

[0072]

[0073] 1. Synthesis of intermediate 4a:

[0074] Place p-tert-butylthiophenol (18.35 g, 110.53 mmol), 2,5-dibromo-1,3-difluorobenzene (9.97 g, 36.80 mmol) and potassium carbonate (15.30 g, 110.70 mmol) in a dry two-necked bottle, evacuate and fill with nitrogen for three cycles, and add N-methylpyrrolidone (NMP) (55 mL) under nitrogen flow. Stir the reaction at 170°C for 24 hours. After cooling to room temperature, remove the NMP solvent by rotary evaporation, add a large amount of water, and extract with ethyl acetate three times. Combine the organic phases and concentrate, and purify with dichloromethane: petroleum ether = 1:10 on a silica gel column to obtain 17.23 g of a yellow solid, which is intermediate 4a, with a yield of 83%. MALDI-TOF-MS (m / z): 564.6 ([M]+ ).

[0075] 2. Synthesis of intermediate 4b:

[0076] Place intermediate 4a (6.71 g, 11.9 mmol), imidazole (1.44 g, 21.2 mmol), CuI (1.0 g, 5.25 mmol), potassium carbonate (3.0 g, 21.7 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 70 mL of dry DMF under nitrogen flow, and stir at 150 ° C for 12 hours. Cool to room temperature, evaporate DMF under reduced pressure, then add a large amount of water, extract with dichloromethane three times, combine the organic phases, concentrate, and then pass through a silica gel column with ethyl acetate: petroleum ether = 1:1 to obtain 2.62 g of yellow solid, which is intermediate 4b, with a yield of 40%. MALDI-TOF-MS (m / z): 552.7 ([M+1] + ).

[0077] 3. Synthesis of intermediate 4c:

[0078] Intermediate 4b (1.61 g, 2.92 mmol) was added to a dry 100 mL schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and it was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, followed by extraction with water and dichloromethane for several times. The combined organic phase was concentrated by rotary evaporation and dried to obtain about 1.05 g of a yellow solid, which was intermediate 4c, with a yield of 75%. MALDI-TOF-MS (m / z): 481.3 ([M+1] + ).

[0079] 4. Synthesis of intermediate 4d:

[0080] Place intermediate 4c (0.96 g, 2 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 20 mL of dry tetrahydrofuran under nitrogen flow, stir at room temperature for ten minutes, then add iodomethane (0.50 mL, 8 mmol), heat to 65 ° C and stir for three days. After the reaction is completed, cool to room temperature, filter and take the filter cake, rinse the filter cake with tetrahydrofuran, and obtain 0.62 g of yellow solid, which is intermediate 4d, with a yield of 50%. ESI-MS (m / z): 495.4 ([MI] + ).

[0081] 5. Synthesis of boron-containing fused-ring carbene iridium complex M4:

[0082] Place intermediate 4d (0.177 g, 0.285 mmol), Ag2O (0.066 g, 0.285 mmol), [Ir(COD)Cl]2 (0.039 g, 0.057 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add triethylamine (0.04 mL, 0.285 mmol) and chlorobenzene (20 mL) under nitrogen flow, and stir at 120 ° C for 24 hours. Cool to room temperature, evaporate the solvent under reduced pressure, and then pass through a silica gel column with dichloromethane: petroleum ether = 1:1 to obtain 57 mg of yellow solid, which is the boron-containing fused ring carbene iridium complex M4, with a yield of 30%. MALDI-TOF-MS (m / z): 1672.8 ([M] + ).

[0083] Example 5 Synthesis of Boron-Containing Condensed Ring Carbene Iridium Complex M5

[0084] Synthesis route of boron-containing fused-ring carbene iridium complex M5:

[0085]

[0086] 1. Synthesis of intermediate 5b:

[0087] Place intermediate 1a (5.0 g, 11.9 mmol), benzimidazole (2.50 g, 21.2 mmol), CuI (1.0 g, 5.25 mmol), potassium carbonate (3.0 g, 21.7 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 70 mL of dry DMF under nitrogen flow, and stir at 150 ° C for 12 hours. Cool to room temperature, evaporate DMF under reduced pressure, then add a large amount of water, extract with dichloromethane three times, combine the organic phases, concentrate, and then pass through a column with ethyl acetate: petroleum ether = 1:1 to obtain 3.26 g of white solid, which is intermediate 5b, with a yield of 60%. MALDI-TOF-MS (m / z): 458.2 ([M+1]+ ).

[0088] 2. Synthesis of intermediate 5c:

[0089] Intermediate 5b (1.33 g, 2.92 mmol) was added to a dry 100 mL schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and it was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, followed by extraction with water and dichloromethane for several times. The combined organic phase was concentrated by rotary evaporation and dried to obtain about 1.01 g of a light yellow solid, which was intermediate 5c, with a yield of 90%. MALDI-TOF-MS (m / z): 387.3 ([M+1] + ).

[0090] 3. Synthesis of intermediate 5d:

[0091] Place intermediate 5c (0.77 g, 2 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 20 mL of dry tetrahydrofuran under nitrogen flow, stir at room temperature for ten minutes, then add iodomethane (0.50 mL, 8 mmol), heat to 65 ° C and stir for three days. After the reaction is completed, cool to room temperature, filter and take the filter cake, rinse the filter cake with tetrahydrofuran, and obtain 0.48 g of white solid, which is intermediate 5d, with a yield of 45%. ESI-MS (m / z): 401.3 ([MI] + ).

[0092] 4. Synthesis of boron-containing fused-ring carbene iridium complex M5:

[0093] Place intermediate 5d (0.15 g, 0.285 mmol), Ag2O (0.066 g, 0.285 mmol), [Ir(COD)Cl]2 (0.039 g, 0.057 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add triethylamine (0.04 mL, 0.285 mmol) and chlorobenzene (20 mL) under nitrogen flow, and stir at 120 ° C for 24 hours. Cool to room temperature, evaporate the solvent under reduced pressure, and then pass through a silica gel column with dichloromethane: petroleum ether = 1:1 to obtain 55 mg of a yellow solid with a yield of 35%. MALDI-TOF-MS (m / z): 1389.7 ([M] + ). The X-ray single crystal structure of M5 is shown in Figure 1 .

[0094] Example 6 Synthesis of Boron-Containing Condensed Ring Carbene Iridium Complex M6

[0095] Synthesis route of boron-containing fused ring carbene iridium complex M6:

[0096]

[0097] 1. Synthesis of intermediate 6b:

[0098] Place intermediate 2a (6.3 g, 11.9 mmol), benzimidazole (2.50 g, 21.2 mmol), CuI (1.0 g, 5.25 mmol), potassium carbonate (3.0 g, 21.7 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 70 mL of dry DMF under nitrogen flow, and stir at 150 ° C for 12 hours. Cool to room temperature, evaporate DMF under reduced pressure, then add a large amount of water, extract with dichloromethane three times, combine the organic phases, concentrate, and then pass through a silica gel column with ethyl acetate: petroleum ether = 1:1 to obtain 3.72 g of white solid, which is intermediate 6b, with a yield of 55%. MALDI-TOF-MS (m / z): 569.3 ([M] + ).

[0099] 2. Synthesis of intermediate 6c:

[0100] Intermediate 6b (1.66 g, 2.92 mmol) was added to a dry 100 mL Schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and the temperature was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, it was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, and then extracted several times with water and dichloromethane. The combined organic phase was concentrated by rotary evaporation and dried to obtain about 1.25 g of a light yellow solid, which was intermediate 6c, with a yield of 86%. MALDI-TOF-MS (m / z): 499.4 ([M+1] + ).

[0101] 3. Synthesis of intermediate 6d:

[0102] Place intermediate 6c (0.99 g, 2 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 20 mL of dry tetrahydrofuran under nitrogen flow, stir at room temperature for ten minutes, then add iodomethane (0.50 mL, 8 mmol), heat to 65 ° C and stir for three days. After the reaction is completed, cool to room temperature, filter and take the filter cake, rinse the filter cake with tetrahydrofuran, and obtain intermediate 6d, 0.59 g of white solid, yield 46%. ESI-MS (m / z): 513.5 ([MI] + ).

[0103] 4. Synthesis of boron-containing fused-ring carbene iridium complex M6:

[0104] Place intermediate 6d (0.182 g, 0.285 mmol), Ag2O (0.066 g, 0.285 mmol), [Ir(COD)Cl]2 (0.039 g, 0.057 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add triethylamine (0.04 mL, 0.285 mmol) and chlorobenzene (20 mL) under nitrogen flow, and stir at 120 ° C for 24 hours. Cool to room temperature, evaporate the solvent under reduced pressure, and then pass through a silica gel column with dichloromethane: petroleum ether = 1:1 to obtain 55 mg of a yellow solid, which is the boron-containing fused ring carbene iridium complex M6, with a yield of 28%. MALDI-TOF-MS (m / z): 1727.5 ([M+1] + ).

[0105] Example 7 Synthesis of Boron-Containing Condensed Ring Carbene Iridium Complex M7

[0106] Synthesis route of boron-containing fused-ring carbene iridium complex M7:

[0107]

[0108] 1. Synthesis of intermediate 7b:

[0109] Place intermediate 3a (5.38 g, 11.9 mmol), benzimidazole (2.50 g, 21.2 mmol), CuI (1.0 g, 5.25 mmol), potassium carbonate (3.0 g, 21.7 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 70 mL of dry DMF under nitrogen flow, and stir at 150 ° C for 12 hours. Cool to room temperature, evaporate DMF under reduced pressure, then add a large amount of water, extract with dichloromethane three times, combine the organic phases, concentrate, and then pass through a silica gel column with ethyl acetate: petroleum ether = 1:1 to obtain 3.03 g of yellow solid, which is intermediate 7b, with a yield of 52%. MALDI-TOF-MS (m / z): 490.5 ([M+1] + ).

[0110] 2. Synthesis of intermediate 7c:

[0111] Intermediate 7b (1.43 g, 2.92 mmol) was added to a dry 100 mL Schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25 mL) was added under a nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and the temperature was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, it was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, and then extracted several times with water and dichloromethane. The combined organic phase was concentrated by rotary evaporation and dried to obtain about 1.05 g of yellow solid, which was intermediate 7c, with a yield of 86%. MALDI-TOF-MS (m / z): 419.3 ([M+1] + ).

[0112] 3. Synthesis of intermediate 7d:

[0113] Place intermediate 7c (0.84 g, 2 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 20 mL of dry tetrahydrofuran under nitrogen flow, stir at room temperature for ten minutes, then add iodomethane (0.50 mL, 8 mmol), heat to 65 ° C and stir for three days. After the reaction is completed, cool to room temperature, filter and take the filter cake, rinse the filter cake with tetrahydrofuran, and obtain 0.56 g of yellow solid, which is intermediate 7d, with a yield of 50%. ESI-MS (m / z): 433.4 ([MI] + ).

[0114] 4. Synthesis of boron-containing fused-ring carbene iridium complex M7:

[0115] Place intermediate 7d (0.159 g, 0.285 mmol), Ag2O (0.066 g, 0.285 mmol), [Ir(COD)Cl]2 (0.039 g, 0.057 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add triethylamine (0.04 mL, 0.285 mmol) and chlorobenzene (20 mL) under nitrogen flow, and stir at 120 ° C for 24 hours. Cool to room temperature, evaporate the solvent under reduced pressure, and then pass through a silica gel column with dichloromethane: petroleum ether = 1:1 to obtain 36 mg of yellow solid, which is the boron-containing fused ring carbene iridium complex M7, with a yield of 21%. MALDI-TOF-MS (m / z): 1486.3 ([M] + ).

[0116] Example 8 Synthesis of Boron-Containing Condensed Ring Carbene Iridium Complex M8

[0117] Synthesis route of boron-containing fused-ring carbene iridium complex M8:

[0118]

[0119] 1. Synthesis of intermediate 8b:

[0120] Place intermediate 4a (6.71 g, 11.9 mmol), benzimidazole (2.50 g, 21.2 mmol), CuI (1.0 g, 5.25 mmol), potassium carbonate (3.0 g, 21.7 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 70 mL of dry DMF under nitrogen flow, and stir at 150 ° C for 12 hours. Cool to room temperature, evaporate DMF under reduced pressure, then add a large amount of water, extract with dichloromethane three times, combine the organic phases, concentrate, and then pass through a silica gel column with ethyl acetate: petroleum ether = 1:1 to obtain 3.72 g of yellow solid, which is intermediate 8b, with a yield of 52%. MALDI-TOF-MS (m / z): 602.6 ([M+1] + ).

[0121] 2. Synthesis of intermediate 8c:

[0122] Intermediate 8b (1.75 g, 2.92 mmol) was added to a dry 100 mL schlenck tube, vacuumed and nitrogen filled for 3 cycles, and then dry m-xylene (25 mL) was added under nitrogen atmosphere. n-Butyl lithium (1.30 mL, 3.21 mmol) was added at 0°C, and the reaction was stirred at 0°C for 20 minutes. Then it was transferred to room temperature and stirred for 1 hour. Then the temperature was lowered to 0°C, boron tribromide (0.50 mL, 5.25 mmol) was added, and it was stirred at 0°C for 20 minutes, and then the mixture was transferred to room temperature and stirred for 30 minutes. After that, the mixture was heated to 45°C and stirred for 50 minutes. Then the temperature was lowered to 0°C again, N,N-diisopropylethylamine (1.00 mL, 5.84 mmol) was added, and finally the mixture was heated to 140°C and stirred for 12 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and the resulting solution was washed with a saturated sodium acetate solution, followed by extraction with water and dichloromethane for several times. The combined organic phase was concentrated by rotary evaporation and dried to obtain about 1.21 g of a yellow solid, which was intermediate 8c, with a yield of 78%. MALDI-TOF-MS (m / z): 531.7 ([M+1] + ).

[0123] 3. Synthesis of intermediate 8d:

[0124] Place intermediate 8c (1.06 g, 2 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 20 mL of dry tetrahydrofuran under nitrogen flow, stir at room temperature for ten minutes, then add iodomethane (0.50 mL, 8 mmol), heat to 65 ° C and stir for three days. After the reaction is completed, cool to room temperature, filter and take the filter cake, rinse the filter cake with tetrahydrofuran, and obtain 0.74 g of yellow solid, which is intermediate 8d, with a yield of 55%. ESI-MS (m / z): 545.5 ([MI] + ).

[0125] 4. Synthesis of boron-containing fused-ring carbene iridium complex M8:

[0126] Place intermediate 8d (0.191 g, 0.285 mmol), Ag2O (0.066 g, 0.285 mmol), [Ir(COD)Cl]2 (0.039 g, 0.057 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add triethylamine (0.04 mL, 0.285 mmol) and chlorobenzene (20 mL) under nitrogen flow, and stir at 120 ° C for 24 hours. Cool to room temperature, evaporate the solvent under reduced pressure, and then pass through a silica gel column with dichloromethane: petroleum ether = 1:1 to obtain 58 mg of yellow solid, which is the boron-containing fused ring carbene iridium complex M8, with a yield of 28%. MALDI-TOF-MS (m / z): 1822.9 ([M] + ).

[0127] Example 9 Synthesis of Boron-Containing Condensed Ring Carbene Iridium Complex M9

[0128] Synthesis route of boron-containing fused-ring carbene iridium complex M9:

[0129]

[0130] 1. Synthesis of intermediate 9a:

[0131] Place 1,5-cyclooctadiene iridium chloride dimer (0.44 g, 0.66 mmol) and biphenylene (0.2 g, 1.31 mmol) in a dry two-necked bottle, evacuate and fill with nitrogen for three cycles, then add 5 mL of dry dichloromethane, stir and react at 90°C for 2 hours, cool to room temperature, filter, and wash the filter cake with dichloromethane to obtain 0.57 g of yellow solid, which is intermediate 9a, with a yield of 85%. MALDI-TOF-MS (m / z): 976.2 ([M] + ).

[0132] 2. Synthesis of intermediate 9b:

[0133] Place intermediate 9a (0.10 g, 0.1 mmol), 2,2'-bipyridine (0.03 g, 0.2 mmol), silver trifluoromethanesulfonate (0.06 g, 0.22 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 25 mL of dry dichloromethane under nitrogen flow, stir at room temperature for 2 hours, filter, concentrate the filtrate to 1 mL, then add a large amount of petroleum ether to precipitate solid, filter, and dry to obtain 0.11 g of yellow solid, which is intermediate 9b, with a yield of 75%. ESI-MS (m / z): 608.7 ([M-OTf] + ).

[0134] 3. Synthesis of boron-containing fused-ring carbene iridium complex M9:

[0135] In a dry two-necked bottle, intermediate 9b (0.076 g, 0.1 mmol), 1d (0.057 g, 0.12 mmol), Na2CO3 (0.03 g, 0.24 mmol) were placed, vacuumed and nitrogen filled for three cycles, then 20 mL of ethylene glycol monoethyl ether was added under nitrogen flow, stirred and refluxed at 130°C for 24 hours, cooled to room temperature, the organic phase was concentrated, then water was added, extracted with dichloromethane, concentrated, and passed through a silica gel column with dichloromethane: petroleum ether = 5:1 to obtain 38 mg of a red solid, which was the boron-containing fused ring carbene iridium complex M9, with a yield of 45%. MALDI-TOF-MS (m / z): 849.5 ([M] + ). The X-ray single crystal structure of M9 is shown in Figure 2 .

[0136] Example 10 Synthesis of Boron-Containing Condensed Ring Carbene Iridium Complex M13

[0137] Synthesis route of boron-containing fused-ring carbene iridium complex M13:

[0138]

[0139] 1. Synthesis of boron-containing fused-ring carbene iridium complex M13:

[0140] In a dry two-necked bottle, intermediate 9b (0.076 g, 0.1 mmol), 5d (0.063 g, 0.12 mmol), Na2CO3 (0.03 g, 0.24 mmol) were placed, vacuumed and nitrogen filled for three cycles, then 20 mL of ethylene glycol monoethyl ether was added under nitrogen flow, stirred and refluxed at 130°C for 24 hours, cooled to room temperature, the organic phase was concentrated, then water was added, extracted with dichloromethane, concentrated, and passed through a silica gel column with dichloromethane: petroleum ether = 5:1 to obtain 43 mg of a red solid, which was the boron-containing fused ring carbene iridium complex M13, with a yield of 48%. MALDI-TOF-MS (m / z): 900.3 ([M+1] + ). The X-ray single crystal structure of M13 is shown in Figure 3 .

[0141] Example 11 Synthesis of Boron-Containing Condensed Ring Carbene Iridium Complex M17

[0142] Synthesis route of boron-containing fused-ring carbene iridium complex M17:

[0143]

[0144] 1. Synthesis of intermediate 10b:

[0145] Place intermediate 1a (0.10 g, 0.1 mmol), 1,10-phenanthroline (0.04 g, 0.2 mmol), silver trifluoromethanesulfonate (0.06 g, 0.22 mmol) in a dry Schlenck bottle, evacuate and fill with nitrogen for three cycles, then add 25 mL of dry dichloromethane under nitrogen flow, stir at room temperature for 2 hours, filter, concentrate the filtrate to 1 mL, then add a large amount of petroleum ether to precipitate solids, filter, and dry to obtain 0.12 g of yellow solid, which is intermediate 10b, with a yield of 75%. ESI-MS (m / z): 632.8 ([M-OTf] + ).

[0146] 2. Synthesis of boron-containing fused-ring carbene iridium complex M17:

[0147] In a dry two-necked bottle, intermediate 10b (0.078 g, 0.1 mmol), 1d (0.057 g, 0.12 mmol), Na2CO3 (0.03 g, 0.24 mmol) were placed, vacuumed and nitrogen filled for three cycles, then 20 mL of ethylene glycol monoethyl ether was added under nitrogen flow, stirred and refluxed at 130°C for 24 hours, cooled to room temperature, the organic phase was concentrated, then water was added, extracted with dichloromethane, concentrated, and passed through a silica gel column with dichloromethane: petroleum ether = 5:1 to obtain 46 mg of a red solid, which was the boron-containing fused ring carbene iridium complex M17, with a yield of 53%. MALDI-TOF-MS (m / z): 873.8 ([M] + ). The X-ray single crystal structure of M17 is shown in Figure 4 .

[0148] Example 12 Synthesis of Boron-Containing Condensed Ring Carbene Iridium Complex M18

[0149] Synthesis route of boron-containing fused-ring carbene iridium complex M18:

[0150]

[0151] 1. Synthesis of boron-containing fused-ring carbene iridium complex M18:

[0152] In a dry two-necked bottle, intermediate 10b (0.078 g, 0.1 mmol), 2d (0.071 g, 0.12 mmol), Na2CO3 (0.03 g, 0.24 mmol) were placed, vacuumed and nitrogen filled for three cycles, then 20 mL of ethylene glycol monoethyl ether was added under nitrogen flow, stirred and refluxed at 130°C for 24 hours, cooled to room temperature, the organic phase was concentrated, then water was added, extracted with dichloromethane, concentrated, and passed through a silica gel column with dichloromethane: petroleum ether = 5:1 to obtain 49 mg of a red solid, which was the boron-containing fused ring carbene iridium complex M18, with a yield of 50%. MALDI-TOF-MS (m / z): 987.1 ([M+1] + ).

[0153] Example 13 Synthesis of Boron-Containing Condensed Ring Carbene Iridium Complex M20

[0154] Synthesis route of boron-containing fused-ring carbene iridium complex M20:

[0155]

[0156] 1. Synthesis of boron-containing fused-ring carbene iridium complex M20:

[0157] Place intermediate 10b (0.078 g, 0.1 mmol), 4d (0.075 g, 0.12 mmol), Na2CO3 (0.03 g, 0.24 mmol) in a dry two-necked bottle, evacuate and fill with nitrogen for three cycles, then add 20 mL of ethylene glycol monoethyl ether under nitrogen flow, stir and reflux at 130°C for 24 hours, cool to room temperature, concentrate the organic phase, then add water, extract with dichloromethane, concentrate, and pass through a silica gel column with dichloromethane: petroleum ether = 5:1 to obtain 44 mg of a red solid, which is the boron-containing fused ring carbene iridium complex M20, with a yield of 43%. MALDI-TOF-MS (m / z): 1018.3 ([M] + ).

[0158] Example 14 Synthesis of Boron-Containing Condensed Ring Carbene Iridium Complex M21

[0159] Synthesis route of boron-containing fused-ring carbene iridium complex M21:

[0160]

[0161] 1. Synthesis of boron-containing fused-ring carbene iridium complex M21:

[0162] In a dry two-necked bottle, intermediate 10b (0.078 g, 0.1 mmol), 5d (0.063 g, 0.12 mmol), Na2CO3 (0.03 g, 0.24 mmol) were placed, vacuumed and nitrogen filled for three cycles, then 20 mL of ethylene glycol monoethyl ether was added under nitrogen flow, stirred and refluxed at 130°C for 24 hours, cooled to room temperature, the organic phase was concentrated, then water was added, extracted with dichloromethane, concentrated, and passed through a silica gel column with dichloromethane: petroleum ether = 5:1 to obtain 48 mg of a red solid, which was the boron-containing fused ring carbene iridium complex M21, with a yield of 52%. MALDI-TOF-MS (m / z): 924.9 ([M] + ). The X-ray single crystal structure of M21 is shown in Figure 5 .

[0163] Example 15 Synthesis of Boron-Containing Condensed Ring Carbene Iridium Complex M22

[0164] Synthesis route of boron-containing fused-ring carbene iridium complex M22:

[0165]

[0166] 1. Synthesis of boron-containing fused-ring carbene iridium complex M22:

[0167] In a dry two-necked bottle, intermediate 10b (0.078 g, 0.1 mmol), 6d (0.076 g, 0.12 mmol), Na2CO3 (0.03 g, 0.24 mmol) were placed, vacuumed and nitrogen filled for three cycles, then 20 mL of ethylene glycol monoethyl ether was added under nitrogen flow, stirred and refluxed at 130°C for 24 hours, cooled to room temperature, the organic phase was concentrated, then water was added, extracted with dichloromethane, concentrated, and passed through a silica gel column with dichloromethane: petroleum ether = 5:1 to obtain 55 mg of a red solid, which was the boron-containing fused ring carbene iridium complex M22, with a yield of 53%. MALDI-TOF-MS (m / z): 1036.1 ([M] + ).

[0168] Example 16 Synthesis of Boron-Containing Condensed Ring Carbene Iridium Complex M24

[0169] Synthesis route of boron-containing fused-ring carbene iridium complex M24:

[0170]

[0171] 1. Synthesis of boron-containing fused-ring carbene iridium complex M24:

[0172] In a dry two-necked bottle, intermediate 10b (0.078 g, 0.1 mmol), 8d (0.081 g, 0.12 mmol), Na2CO3 (0.03 g, 0.24 mmol) were placed, vacuumed and nitrogen filled for three cycles, then 20 mL of ethylene glycol monoethyl ether was added under nitrogen flow, stirred and refluxed at 130°C for 24 hours, cooled to room temperature, the organic phase was concentrated, then water was added, extracted with dichloromethane, concentrated, and passed through a silica gel column with dichloromethane: petroleum ether = 5:1 to obtain 52 mg of a red solid, which was the boron-containing fused ring carbene iridium complex M24, with a yield of 49%. MALDI-TOF-MS (m / z): 1069.3 ([M+1] + ).

[0173] Example 17 Synthesis of Boron-Containing Condensed Ring Carbene Platinum Complex M28

[0174] Synthesis route of boron-containing fused ring carbene platinum complex M28:

[0175]

[0176] 1. Synthesis of boron-containing fused-ring carbene platinum complex M35:

[0177] In a dry Schlenck bottle, intermediate 2d (0.472 g, 0.8 mmol) and Ag2O (0.092 g, 0.4 mmol) were placed, and the vacuum was evacuated and nitrogen was filled for three cycles. Then, 1,4-dioxane (20 mL) was added under a nitrogen flow, and the mixture was stirred at room temperature for 16 hours. Then, butanone (10 mL) and 1,5-cyclooctadiene dichloroplatinum (0.299 g, 0.8 mmol) were added under nitrogen, and then heated and stirred under reflux for 16 hours. After cooling to room temperature, the solvent was evaporated under reduced pressure, and then DMF (20 mL) was added to dissolve it, followed by the addition of 2,2,6,6-tetramethyl-3,5-heptanedione (0.67 mL, 3.2 mmol) and potassium tert-butoxide (0.359 g, 3.2 mmol), stirred at room temperature for 16 hours under nitrogen, and then stirred at 100°C for 6 hours, cooled to room temperature, the solvent was evaporated under reduced pressure, and then passed through a silica gel column with dichloromethane to obtain 0.268 g of an orange solid, which was the boron-containing fused ring carbene platinum complex M28, with a yield of 40%. MALDI-TOF-MS (m / z): 840.8 ([M+1] + ).

[0178] Example 18 Synthesis of Boron-Containing Condensed Ring Carbene Platinum Complex M36

[0179] Synthesis route of boron-containing fused ring carbene platinum complex M36:

[0180]

[0181] 1. Synthesis of boron-containing fused-ring carbene platinum complex M36:

[0182] In a dry Schlenck bottle, intermediate 6d (0.512 g, 0.8 mmol) and Ag2O (0.092 g, 0.4 mmol) were placed, vacuumed and filled with nitrogen for three cycles, then 1,4-dioxane (20 mL) was added under a nitrogen flow, stirred at room temperature for 16 hours, then butanone (10 mL) and 1,5-cyclooctadiene dichloroplatinum (0.299 g, 0.8 mmol) were added under nitrogen, and then heated and stirred under reflux for 16 hours. After cooling to room temperature, the solvent was evaporated under reduced pressure, and then DMF (20 mL) was added to dissolve it, followed by the addition of 2,2,6,6-tetramethyl-3,5-heptanedione (0.67 mL, 3.2 mmol) and potassium tert-butoxide (0.359 g, 3.2 mmol), stirred at room temperature for 16 hours under nitrogen, and then stirred at 100°C for 6 hours, cooled to room temperature, the solvent was evaporated under reduced pressure, and then passed through a silica gel column with dichloromethane to obtain 0.249 g of an orange solid, which was the boron-containing fused ring carbene platinum complex M36, with a yield of 35%. MALDI-TOF-MS (m / z): 889.8 ([M] + ).

[0183] Example 19 Preparation and Characterization of OLED Devices

[0184] The preparation steps of OLED devices with ITO / PEDOT:PSS(50nm) / M1-M36(1wt%):mCP and m-MTDATA(40nm) / DPEPO(10nm) / TmPyPB(50nm) / Liq(1nm) / Al(100nm) are as follows:

[0185] (i) using an aqueous solution of 5% Decon90 cleaning solution for ultrasonic treatment for 30 minutes, followed by ultrasonic cleaning with deionized water for several times, and then ultrasonic cleaning with isopropanol, followed by drying with nitrogen; treating with oxygen plasma for 5 minutes to clean the ITO surface and improve the work function of the ITO electrode;

[0186] (ii) Spin coating a PEDOT:PSS solution on an ITO glass substrate treated with oxygen plasma to obtain a 50 nm film, which was then annealed in air at 150°C for 20 minutes. PEDOT:PSS is an aqueous solution of a high molecular polymer, which is composed of two substances, PEDOT and PSS. PEDOT is a polymer of 3,4-ethylenedioxythiophene monomers, and PSS is polystyrene sulfonate.

[0187] (iii) mCP, m-MTDATA, and complexes (M1 to M36) were first dissolved in toluene according to a certain mass ratio, wherein complexes M1 to M36 were doped as guest materials in a weight ratio of 1 wt% in the mixed host materials mCP and m-MTDATA, and the solution was spin-coated in a nitrogen glove box to obtain a 40 nm film, which was then annealed at 120° C. for 10 minutes. mCP is the abbreviation of 1,3-dicarbazole-9-ylbenzene, and m-MTDATA is the abbreviation of 4,4',4"-tri(N-3-methylphenyl-N-phenylamino)triphenylamine.

[0188] (iv) Place the spin-coated device into a vacuum evaporation chamber, and sequentially evaporate 10nm DPEPO, 50nm TmPyPB, 1nm Liq and 100nm aluminum to obtain an OLED light-emitting device. DPEPO is the abbreviation of di[2-((oxy)diphenylphosphino)phenyl]ether, TmPyPB is the abbreviation of 1,3,5-tri(3-pyridyl-3-phenyl)benzene, and Liq is the abbreviation of 8-hydroxyquinoline lithium. The current-voltage-luminance (JVL) characteristics of the OLED device are characterized by characterization equipment, and important parameters such as efficiency and external quantum efficiency are recorded at the same time. After testing, the maximum external quantum efficiency (EQE) of OLED is 23%. The details are as follows:

[0189] Complex M1 M2 M3 M4 M5 M6 M7 M8 M9 EQE 19.5％ 20.5％ 18.7％ 19.3％ 22.5％ 23％ 19.4％ 20.5％ 16.2％ Complex M13 M17 M18 M20 M21 M22 M24 M35 M36 EQE 16.5％ 17.2％ 17.5％ 16.3％ 18.2％ 18.7％ 13.2％ 19.5％ 20.3％

[0190] Further optimization, such as optimization of device structure, combination optimization of hole transport material (HTM), electron transport material (ETM) and host material, will further improve the performance of the device, especially efficiency, driving voltage and lifespan.

Claims

1. A boron-containing fused-ring carbene iridium and platinum complex, the general formula of which is shown in the structure (AH): in, X is an O atom or an S atom, and R is a H atom or a tert-butyl group.

2. The boron-containing fused-ring carbene iridium and platinum complex according to claim 1, characterized in that: The boron-containing fused-ring carbene iridium and platinum complex is selected from the following compounds M1-M40:

3. The method for preparing the boron-containing fused-ring carbene iridium and platinum complex according to claim 1 or 2, characterized in that: The following steps are involved: 1) First, 2,5-dibromo-1,3-difluorobenzene is used as a raw material, and phenol and its derivatives or thiophenol and its derivatives are subjected to fluorine substitution reaction in an alkaline high temperature environment to obtain a first-step precursor, and then the precursor is subjected to Ullmann reaction with imidazole or benzimidazole in the presence of a base and cuprous iodide to obtain a corresponding second-step precursor; 2) The second-step precursor prepared in step 1) is further subjected to anhydrous, oxygen-free and low-temperature conditions, using n-butyl lithium n-BuLi to remove bromine atoms in a dry m-xylene solution, and then adding boron tribromide to react with stirring, and finally in an alkaline environment of N,N-diisopropylethylamine, by controlling the reaction temperature and time, a boron-containing fused ring intermediate compound can be obtained, and then methyl iodide is used to perform a methylation reaction to form a boron-containing fused ring imidazole salt or benzimidazole salt ligand; 3) Finally, the boron-containing fused ring imidazole salt or benzimidazole salt ligand prepared in step 2) is used to carry out coordination reaction with metal iridium and platinum respectively to obtain boron-containing fused ring carbene iridium and platinum complexes.

4. The method for preparing the boron-containing fused-ring carbene iridium and platinum complex according to claim 3, characterized in that: In step 1), the reaction temperature is 150-170° C. and the reaction time is 12-24 hours.

5. The method for preparing the boron-containing fused-ring carbene iridium and platinum complex according to claim 3, characterized in that: In step 2), the low temperature condition is 0°C to 45°C, and the reaction time is 20 to 120 minutes.

6. The method for preparing the boron-containing fused-ring carbene iridium and platinum complex according to claim 3, characterized in that: In step 3), the reaction temperature is 100-130° C. and the reaction time is 6-24 h.

7. Use of the boron-containing fused-ring carbene iridium and platinum complex according to claim 1 or 2 in the preparation of organic electronic devices.

8. The use according to claim 7, characterized in that: The organic electronic device includes one or more of an organic light emitting diode, an organic photovoltaic cell, an organic light emitting cell, an organic field effect transistor, an organic laser, an organic spin electronic device, an organic sensor or an organic plasmon emission diode.

9. The use according to claim 7, characterized in that: The mass concentration of the boron-containing fused-ring carbene iridium and platinum complex in the matrix is ​​1-15wt%.

10. An organic electronic device, characterized in that: The organic electronic device comprises the boron-containing fused-ring carbene iridium and platinum complex according to claim 1 or 2.

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