Neutral iridium dinuclear complex, method for producing the same, and uses

Abstract

This invention discloses a neutral iridium dinuclear complex, a method for producing the same, and its applications in the manufacture of organic electronic devices. The invention further relates to organic electronic devices containing the neutral iridium dinuclear complex according to the present invention, particularly organic light-emitting diodes, and their applications in display and lighting technologies. Through optimization of the device structure, the concentration of this neutral iridium dinuclear complex in the matrix can be varied to achieve optimal device performance, making it easier to realize highly efficient, high-brightness, and highly stable OLED devices, and providing a relatively good material option for full-color display and lighting applications.

Description

[Technical Field]

[0001] This invention belongs to the field of novel materials technology, and more specifically relates to neutral iridium dinuclear complexes, methods for producing the same, and applications, and in particular to applications in organic light-emitting diodes. [Background technology]

[0002] Organic semiconductor materials offer great versatility in synthesis, low manufacturing costs, and excellent optical and electrical properties, making organic light-emitting diodes (OLEDs) highly promising for use in photoelectric devices (e.g., flat panel displays and lighting). To improve the luminescence efficiency of OLEDs, various luminescent material systems based on fluorescence and phosphorescence have been developed. While OLEDs using fluorescent materials are characterized by their high reliability, their internal electroluminescence quantum efficiency under electric field excitation is limited to 25%. This is because the ratio of the probability of an exciton generating a single excitation state to the probability of it generating a triple excitation state is 1:3.

[0003] In 1999, Professor Thomson of the University of Southern California and Professor Forrest of Princeton University successfully fabricated a green phosphorescent electroluminescent device by doping N,N-dicarbazolylbiphenyl (CBP) with tris(2-phenylpyridinato)iridium(III)Ir(ppy)3, which sparked interest in complex phosphorescent materials. The introduction of heavy metals improves molecular spin-orbit coupling, shortens the phosphorescence lifetime, strengthens intersystem crossing between molecules, and allows for smooth phosphorescence emission. To date, the internal quantum efficiency of phosphorescent OLEDs has reached nearly 100%.

[0004] However, because dinuclear metallic iridium complexes have two metallic iridium centers, their coordination patterns are richer than those of mononuclear metallic iridium complexes, which is advantageous for controlling and improving the overall luminescence performance of the complex. Nevertheless, there is currently limited selection of bridging ligands that connect the two metallic centers, making it difficult to improve the luminescence performance of the complex. Therefore, selecting an appropriate bridging ligand is crucial for improving and tuning the optical performance of the complex. Furthermore, designing biphenyl ligands with strong ligand field effects for dinuclear neutral metallic iridium complexes is a significant challenge. [Overview of the project] [Problems that the invention aims to solve]

[0005] Objective of the Invention: In view of the shortcomings of the prior art described above, the technical problem that the present invention aims to solve is to provide a novel neutral iridium dinuclear complex with strong stability and luminescence performance. [Means for solving the problem]

[0006] A further technical problem that this invention aims to solve is to provide a method for producing a neutral iridium dinuclear complex.

[0007] A further technical problem that this invention aims to solve is to provide applications for neutral iridium dinuclear complexes in the manufacture of organic electronic devices.

[0008] The final technical problem that this invention aims to solve is to provide an organic electronic device containing the neutral iridium dinuclear complex.

[0009] Technical proposal: The present invention relates to a neutral iridium dinuclear complex, the general formula of which is shown in structure (I) or (II), [ka] The formula described in Formula I or II [ka] is a bidentate ligand, and both of the two coordinating atoms are A, which may be selected from a nitrogen atom or a phosphorus atom, and X described in Formula I or II is an oxygen or sulfur atom, providing a neutral dinuclear iridium complex.

[0010] The neutral dinuclear iridium complex is selected from the following complexes IrIr1 - IrIr20.

Chemical formula

[0011] The summary of the present invention is a method for producing the neutral dinuclear iridium complex, comprising: First, chloro(1,5-cyclooctadiene)iridium(I) (dimer) and biphenylene are used as raw materials respectively, and under anhydrous and oxygen-free conditions, oxidative addition reaction is carried out to achieve the coordination of the dianionic ligand biphenyl and metal iridium, finally forming the precursor 1-a of the first step. Then, a chlorine atom is removed under the action of silver trifluoromethanesulfonate, and a neutral ligand

Chemical formula

[0012] The sulfur-containing ligand in step 2) includes one or more of 2-mercaptobenzothiazole, 2-mercaptobenzothiazole or 2-mercaptooxazole.

[0013] The preferred temperature in step 2) is 70 °C.

[0014] The outline of the present invention further includes applications of the neutral iridium dinuclear complex in the manufacture of organic electronic devices.

[0015] The aforementioned organic electronic devices include organic light-emitting diodes (OLEDs), organic solar cells (OPVs), organic light-emitting cells (OLEECs), organic field-effect transistors (OFETs), organic lasers, organic spin-electron devices, organic sensors, and organic plasmon-emitting diodes.

[0016] The mass concentration of the neutral iridium dinuclear complex in the matrix is ​​3-10 wt%.

[0017] The outline of the present invention further includes the organic electronic device comprising the neutral iridium dinuclear complex.

[0018] The mass concentration of the neutral iridium dinuclear complex is 3 to 10 wt%.

[0019] Preferably, the mass concentration of the neutral iridium dinuclear complex is 5 wt%. [Effects of the Invention]

[0020] Beneficial Effects: Compared to prior art, the present invention offers the following advantages. The novel neutral iridium dinuclear complex prepared in the present invention not only possesses a biphenyl ligand with a strong field effect, but also a sulfur-containing ligand with strong rigidity and electronic effect, thereby enhancing the stability of the compound, its luminescence performance, and the performance of the corresponding device. The present invention further relates to organic electronic devices, particularly organic light-emitting diodes, and their applications in display and lighting technologies, containing the dinuclear neutral metallic iridium complex according to the present invention. By optimizing the device structure, the concentration of this dinuclear neutral metallic iridium complex in the matrix can be varied to achieve optimal device performance, making it easier to realize highly efficient, high-brightness, and highly stable OLED devices, and providing a relatively good material option for full-color display and lighting applications. [Brief explanation of the drawing]

[0021] [Figure 1] This is the X-ray single crystal structure of the neutral iridium dinuclear complex IrIr1. [Figure 2] This is the X-ray single crystal structure of the neutral iridium dinuclear complex IrIr2. [Modes for carrying out the invention]

[0022] Example 1: Synthesis of neutral iridium dinuclear complex IrIr1 Synthetic route of the neutral iridium dinuclear complex IrIr1: [ka]

[0023] 1. Synthesis of intermediate 1-a: Chloro(1,5-cyclooctadiene)iridium(I) (dimer) (0.44 g, 0.66 mmol) and biphenylene (0.2 g, 1.31 mmol) were placed in a dry Schlenk tube, and the tube was vacuumed and filled with nitrogen gas three times. Then 5 mL of dry dichloromethane was added, and the mixture was stirred at 90°C for 2 hours. After cooling to room temperature, the mixture was filtered by suction, and the filter cake was washed with dichloromethane to obtain 0.57 g of a yellow solid intermediate 1-a in 85% yield. MALDI-TOF-MS (m / z): 976.1 ([M] + ).

[0024] 2. Synthesis of intermediate 1-b: In a dry Schlenk tube, intermediate 1-a (0.10 g, 0.1 mmol), bipyridine (0.03 g, 0.2 mmol), and silver trifluoromethanesulfonate (0.06 g, 0.22 mmol) were placed, and the tube was vacuumed and filled with nitrogen gas, repeating this process three times. Then, 25 mL of dry dichloromethane was added using a nitrogen gas flow, the mixture was stirred at room temperature for 2 hours, and the mixture was filtered by suction. The filtrate was concentrated to 1 mL, and a large amount of petroleum ether was added to precipitate the solid. The mixture was filtered by suction and dried to obtain 0.06 g of yellow solid intermediate 1-b in 75% yield. ESI-MS (m / z): 609.2 ([M-OTf] + ).

[0025] 3. Neutral iridium dinuclear complex IrIr1: In a dry Schlenk tube, intermediate 1-b (0.04 g, 0.05 mmol), 2-mercaptobenzthiazole (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed, and the tube was vacuumed and filled with nitrogen gas three times. Then, 10 mL of ethylene glycol ether was added using a nitrogen gas flow, and the reaction was stirred at 70°C for 24 hours. After cooling to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane, concentrated, and passed through a column with dichloromethane:petroleum ether in a 5:1 ratio to obtain 20 mg of the orange solid neutral iridium dinuclear complex IrIr1 in 30% yield. MALDI-TOF-MS (m / z): 1302.2 ([M] + ).

[0026] A single crystal of the neutral iridium dinuclear complex IrIr1 was obtained by gradually diffusing it into a dichloromethane solution using ethanol, and its structure is shown in Figure 1.

[0027] Example 2 Synthesis of neutral iridium dinuclear complex IrIr2 Synthetic route of the neutral iridium dinuclear complex IrIr2: [ka]

[0028] 1. Synthesis of intermediate 1-c: In a dry Schlenk tube, intermediate 1-a (0.10 g, 0.1 mmol), 1,10-O-phenanthroline (0.04 g, 0.2 mmol), and silver trifluoromethanesulfonate (0.06 g, 0.22 mmol) were placed, and the tube was vacuumed and filled with nitrogen gas three times. Then, 25 mL of dry dichloromethane was added using a nitrogen gas flow, the mixture was stirred at room temperature for 2 hours, and the mixture was filtered by suction. The filtrate was concentrated to 1 mL, and a large amount of petroleum ether was added to precipitate the solid. The mixture was filtered by suction and dried to obtain 0.06 g of the yellow solid intermediate 1-c in 75% yield. ESI-MS (m / z): 633.1 ([M-OTf] + ).

[0029] 2. Neutral iridium dinuclear complex IrIr2: In a dry Schlenk tube, intermediate 1-c (0.04 g, 0.05 mmol), 2-mercaptobenzthiazole (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed, and the tube was vacuumed and filled with nitrogen gas, and 10 mL of ethylene glycol ether was added using a nitrogen gas flow. The reaction was stirred at 70°C for 24 hours, cooled to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane, concentrated, and passed through a column with dichloromethane:petroleum ether in a 5:1 ratio to obtain 27 mg of orange solid neutral iridium dinuclear complex IrIr2 in 40% yield. MALDI-TOF-MS (m / z): 1350.2 ([M] + ).

[0030] A single crystal of the neutral iridium dinuclear complex IrIr2 was obtained by gradually diffusing it into a dichloromethane solution using ethanol, and its structure is shown in Figure 2.

[0031] Example 3 Synthesis of neutral iridium dinuclear complex IrIr3 Synthetic route of neutral iridium dinuclear complex IrIr3: [ka]

[0032] 1. Synthesis of intermediate 1-d: In a dry Schlenk tube, intermediate 1-a (0.10 g, 0.1 mmol), pyrazino[2,3-f][1,10]phenanthroline (CAS No. 217-90-3, 0.05 g, 0.2 mmol), and silver trifluoromethanesulfonate (0.06 g, 0.22 mmol) were placed, and the mixture was vacuumed and filled with nitrogen gas three times. Then, 25 mL of dry dichloromethane was added using a nitrogen gas flow, the mixture was stirred at room temperature for 2 hours, filtered by suction, the filtrate was concentrated to 1 mL, and a large amount of petroleum ether was added to precipitate the solid. The mixture was filtered by suction and dried to obtain 0.07 g of yellow solid intermediate 1-d in 80% yield. ESI-MS (m / z): 684.8 ([M-OTf] + ).

[0033] 2. Neutral iridium dinuclear complex IrIr3: In a dry Schlenk tube, 1-d (0.04 g, 0.05 mmol), 2-mercaptobenzthiazole (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed, and the tube was vacuumed and filled with nitrogen gas, and 10 mL of ethylene glycol ether was added using a nitrogen gas flow. The mixture was stirred at 70°C for 24 hours, cooled to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane, concentrated, and passed through a column with dichloromethane:petroleum ether in a 5:1 ratio to obtain 25 mg of orange solid neutral iridium dinuclear complex IrIr3 in 35% yield. MALDI-TOF-MS (m / z): 1454.3 ([M] + ).

[0034] Example 4 Synthesis of neutral iridium dinuclear complex IrIr4 Synthetic route of the neutral iridium dinuclear complex IrIr4: [ka]

[0035] 1. Synthesis of intermediate 1-e: Into a dried Schlenk tube, 1-a (0.10 g, 0.1 mmol), 1,2-bis(diphenylphosphino)benzene (0.09 g, 0.2 mmol), and silver trifluoromethanesulfonate (0.06 g, 0.22 mmol) were added. The tube was evacuated and filled with nitrogen gas three times, and then 25 mL of dried dichloromethane was added under a nitrogen gas flow. The mixture was stirred at room temperature for 2 hours, filtered by suction, the filtrate was concentrated to 1 mL, and a large amount of petroleum ether was added to precipitate a solid. The solid was filtered by suction and dried to obtain 0.08 g of yellow solid intermediate 1-e in a yield of 80%. ESI-MS (m / z): 899.2 ([M-OTf] + ).

[0036] 2. Neutral iridium dinuclear complex IrIr4: Into a dried Schlenk tube, 1-e (0.05 g, 0.05 mmol), 2-mercaptobenzothiazole (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were added. The tube was evacuated and filled with nitrogen gas three times, and then 10 mL of ethylene glycol ether was added under a nitrogen gas flow. The mixture was stirred and reacted at 70 °C for 24 hours, cooled to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane, concentrated, and passed through a column with dichloromethane:petroleum ether at 5:1 to obtain 38 mg of yellow solid neutral iridium dinuclear complex IrIr4 in a yield of 40%. MALDI-TOF-MS (m / z): 1882.3 ([M] + ).

[0037] Example 5 Synthesis of neutral iridium dinuclear complex IrIr5 Synthesis route of neutral iridium dinuclear complex IrIr5:

Chemical formula

[0038] Synthesis of intermediate 1-f: In a dry Schlenk tube, 1-a (0.10 g, 0.1 mmol), 1,2-bis(diphenylphosphin)ethane (0.08 g, 0.2 mmol), and silver trifluoromethanesulfonate (0.06 g, 0.22 mmol) were placed, and the tube was vacuumed and filled with nitrogen gas, repeating this process three times. Then, 25 mL of dry dichloromethane was added using a nitrogen gas flow, the mixture was stirred at room temperature for 2 hours, and the mixture was filtered by suction. The filtrate was concentrated to 1 mL, and a large amount of petroleum ether was added to precipitate the solid. The mixture was filtered by suction and dried to obtain 0.08 g of a yellow solid intermediate 1-f in 80% yield. ESI-MS (m / z): 851.3 ([M-OTf] + ).

[0039] Neutral iridium dinuclear complex IrIr5: In a dry Schlenk tube, intermediate 1-f (0.05 g, 0.05 mmol), 2-mercaptobenzthiazole (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed, and the tube was vacuumed and filled with nitrogen gas, and 10 mL of ethylene glycol ether was added using a nitrogen gas flow. The reaction was stirred at 70°C for 24 hours, cooled to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane, concentrated, and passed through a column with dichloromethane:petroleum ether in a 5:1 ratio to obtain 38 mg of the yellow solid neutral iridium dinuclear complex IrIr5 in 40% yield. MALDI-TOF-MS (m / z): 1786.3 ([M] + ).

[0040] Example 6: Synthesis of the neutral iridium dinuclear complex IrIr6 Synthetic route of the neutral iridium dinuclear complex IrIr6: [ka]

[0041] Neutral iridium dinuclear complex IrIr6: In a dry Schlenk tube, intermediate 1-b (0.04 g, 0.05 mmol), 2-mercaptobenzothiazole (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed, and the tube was vacuumed and filled with nitrogen gas, and 10 mL of ethylene glycol ether was added using a nitrogen gas flow. The reaction was stirred at 70°C for 24 hours, cooled to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane, concentrated, and passed through a column with dichloromethane:petroleum ether in a 5:1 ratio to obtain 30 mg of orange solid neutral iridium dinuclear complex IrIr6 in 45% yield. MALDI-TOF-MS (m / z): 1334.3 ([M] + ).

[0042] Example 7 Synthesis of neutral iridium dinuclear complex IrIr7 Synthetic route of the neutral iridium dinuclear complex IrIr7: [ka]

[0043] Neutral iridium dinuclear complex IrIr7: In a dry Schlenk tube, intermediate 1-c (0.04 g, 0.05 mmol), 2-mercaptobenzothiazole (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed, and the mixture was evacuated and filled with nitrogen gas three times. Then, 10 mL of ethylene glycol ether was added using a nitrogen gas flow, and the mixture was stirred at 70°C for 24 hours. After cooling to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane. The mixture was concentrated, and dichloromethane:petroleum ether was passed through a column in a 5:1 ratio to obtain 28 mg of the orange solid neutral iridium dinuclear complex IrIr7 in 40% yield. MALDI-TOF-MS (m / z): 1383.1 ([M+1] + ).

[0044] Example 8 Synthesis of neutral iridium dinuclear complex IrIr8 Synthetic route of the neutral iridium dinuclear complex IrIr8: [ka]

[0045] Neutral iridium dinuclear complex IrIr8: In a dry Schlenk tube, intermediate 1-d (0.04 g, 0.05 mmol), 2-mercaptobenzothiazole (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed, and the process was repeated three times under vacuum and filled with nitrogen gas. Then, 10 mL of ethylene glycol ether was added using a nitrogen gas flow, and the reaction was stirred at 70°C for 24 hours. After cooling to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane, concentrated, and passed through a column with dichloromethane:petroleum ether in a 5:1 ratio to obtain 22 mg of the orange solid neutral iridium dinuclear complex IrIr8 in 30% yield. MALDI-TOF-MS (m / z): 1486.2 ([M] + ).

[0046] Example 9 Synthesis of neutral iridium dinuclear complex IrIr9 Synthetic route of the neutral iridium dinuclear complex IrIr9: [ka]

[0047] Neutral iridium dinuclear complex IrIr9: In a dry Schlenk tube, intermediate 1-e (0.05 g, 0.05 mmol), 2-mercaptobenzothiazole (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed, and the mixture was evacuated and filled with nitrogen gas three times. Then, 10 mL of ethylene glycol ether was added using a nitrogen gas flow, and the mixture was stirred at 70°C for 24 hours. After cooling to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane. The mixture was concentrated, and dichloromethane:petroleum ether was passed through the column in a 5:1 ratio to obtain 38 mg of the yellow solid neutral iridium dinuclear complex IrIr9 in 40% yield. MALDI-TOF-MS (m / z): 1914.3 ([M] + ).

[0048] Example 10 Synthesis of neutral iridium dinuclear complex IrIr10 Synthetic route of the neutral iridium dinuclear complex IrIr10: [ka]

[0049] Neutral iridium dinuclear complex IrIr10: In a dry Schlenk tube, intermediate 1-f (0.05 g, 0.05 mmol), 2-mercaptobenzothiazole (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed, and the process was repeated three times under vacuum and filled with nitrogen gas. Then, 10 mL of ethylene glycol ether was added using a nitrogen gas flow, and the reaction was stirred at 70°C for 24 hours. After cooling to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane. The mixture was concentrated, and dichloromethane:petroleum ether was passed through the column in a 5:1 ratio to obtain 32 mg of the yellow solid neutral iridium dinuclear complex IrIr10 in 35% yield. MALDI-TOF-MS (m / z): 1818.3 ([M] + ).

[0050] Example 11: Synthesis of neutral iridium dinuclear complex IrIr11 Synthetic route of neutral iridium dinuclear complex IrIr11: [ka]

[0051] Neutral iridium dinuclear complex IrIr11: Intermediate 1-b (0.04 g, 0.05 mmol), 2-mercaptoxazolyl (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed in a dry Schlenk tube, and the tube was vacuumed and filled with nitrogen gas, and 10 mL of ethylene glycol ether was added using a nitrogen gas flow. The reaction was stirred at 70°C for 24 hours, cooled to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane, concentrated, and passed through a column with dichloromethane:petroleum ether in a 5:1 ratio to obtain 18 mg of orange solid neutral iridium dinuclear complex IrIr11 in 30% yield. MALDI-TOF-MS (m / z): 1202.2 ([M] + ).

[0052] Example 12 Synthesis of neutral iridium dinuclear complex IrIr12 Synthetic route of the neutral iridium dinuclear complex IrIr12: [ka]

[0053] Neutral iridium dinuclear complex IrIr12: In a dry Schlenk tube, intermediates 1-c (0.04 g, 0.05 mmol), 2-mercaptoxazolyl (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed, and the mixture was evacuated and filled with nitrogen gas three times. Then, 10 mL of ethylene glycol ether was added using a nitrogen gas flow, and the mixture was stirred at 70°C for 24 hours. After cooling to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane. The mixture was concentrated, and dichloromethane:petroleum ether was passed through a column in a 5:1 ratio to obtain 26 mg of the orange solid neutral iridium dinuclear complex IrIr12 in 42% yield. MALDI-TOF-MS (m / z): 1250.1 ([M] + ).

[0054] Example 13 Synthesis of neutral iridium dinuclear complex IrIr13 Synthetic route of the neutral iridium dinuclear complex IrIr13: [ka]

[0055] Neutral iridium dinuclear complex IrIr13: In a dry Schlenk tube, intermediate 1-d (0.04 g, 0.05 mmol), 2-mercaptoxazolyl (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed, and the process was repeated three times under vacuum and filled with nitrogen gas. Then, 10 mL of ethylene glycol ether was added using a nitrogen gas flow, and the reaction was stirred at 70°C for 24 hours. After cooling to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane. The mixture was concentrated, and dichloromethane:petroleum ether was passed through a column in a 5:1 ratio to obtain 26 mg of the orange solid neutral iridium dinuclear complex IrIr13 in 38% yield. MALDI-TOF-MS (m / z): 1354.1 ([M] + ).

[0056] Example 14 Synthesis of neutral iridium dinuclear complex IrIr14 Synthetic route of the neutral iridium dinuclear complex IrIr14: [ka]

[0057] Neutral iridium dinuclear complex IrIr14: In a dry Schlenk tube, intermediates 1-e (0.05 g, 0.05 mmol), 2-mercaptoxazolyl (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed, and the process was repeated three times under vacuum and filled with nitrogen gas. Then, 10 mL of ethylene glycol ether was added using a nitrogen gas flow, and the reaction was stirred at 70°C for 24 hours. After cooling to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane. The mixture was concentrated, and dichloromethane:petroleum ether was passed through the column in a 5:1 ratio to obtain 37 mg of the yellow solid neutral iridium dinuclear complex IrIr14 in 42% yield. MALDI-TOF-MS (m / z): 1782.3 ([M] + ).

[0058] Example 15 Synthesis of neutral iridium dinuclear complex IrIr15 Synthetic route of the neutral iridium dinuclear complex IrIr15: [ka]

[0059] Neutral iridium dinuclear complex IrIr15: In a dry Schlenk tube, intermediates 1-f (0.05 g, 0.05 mmol), 2-mercaptoxazolyl (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed, and the process was repeated three times under vacuum and filled with nitrogen gas. Then, 10 mL of ethylene glycol ether was added using a nitrogen gas flow, and the reaction was stirred at 70°C for 24 hours. After cooling to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane. The mixture was concentrated, and dichloromethane:petroleum ether was passed through the column in a 5:1 ratio to obtain 34 mg of the yellow solid neutral iridium dinuclear complex IrIr15 in 40% yield. MALDI-TOF-MS (m / z): 1686.3 ([M] + ).

[0060] Example 16: Synthesis of the neutral iridium dinuclear complex IrIr16 Synthetic route of the neutral iridium dinuclear complex IrIr16: [ka]

[0061] Neutral iridium dinuclear complex IrIr16: Intermediate 1-b (0.04 g, 0.05 mmol), 2-mercaptothiazole (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed in a dry Schlenk tube, and the tube was vacuumed and filled with nitrogen gas three times. Then 10 mL of ethylene glycol ether was added using a nitrogen gas flow, and the reaction was stirred at 70°C for 24 hours. After cooling to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane, concentrated, and passed through a column with dichloromethane:petroleum ether in a 5:1 ratio to obtain 22 mg of the orange solid neutral iridium dinuclear complex IrIr16 in 35% yield. MALDI-TOF-MS (m / z): 1234.1 ([M] + ).

[0062] Example 17 Synthesis of neutral iridium dinuclear complex IrIr17 Synthetic route of the neutral iridium dinuclear complex IrIr17: [ka]

[0063] Neutral iridium dinuclear complex IrIr17: Intermediate 1-c (0.04 g, 0.05 mmol), 2-mercaptothiazole (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed in a dry Schlenk tube, and the tube was vacuumed and filled with nitrogen gas three times. Then 10 mL of ethylene glycol ether was added using a nitrogen gas flow, and the reaction was stirred at 70°C for 24 hours. After cooling to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane. The mixture was concentrated, and dichloromethane:petroleum ether was passed through the column in a 5:1 ratio to obtain 26 mg of orange solid neutral iridium dinuclear complex IrIr17 in 40% yield. MALDI-TOF-MS (m / z): 1282.1 ([M] + ).

[0064] Example 18 Synthesis of neutral iridium dinuclear complex IrIr18 Synthetic route of the neutral iridium dinuclear complex IrIr18: [ka]

[0065] Neutral iridium dinuclear complex IrIr18: In a dry Schlenk tube, intermediate 1-d (0.04 g, 0.05 mmol), 2-mercaptothiazole (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed, and the mixture was evacuated and filled with nitrogen gas three times. Then, 10 mL of ethylene glycol ether was added using a nitrogen gas flow, and the mixture was stirred at 70°C for 24 hours. After cooling to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane. The mixture was concentrated, and dichloromethane:petroleum ether was passed through the column in a 5:1 ratio to obtain 26 mg of the orange solid neutral iridium dinuclear complex IrIr18 in 38% yield. MALDI-TOF-MS (m / z): 386.1 ([M] + ).

[0066] Example 19 Synthesis of neutral iridium dinuclear complex IrIr19 Synthetic route of the neutral iridium dinuclear complex IrIr19: [ka]

[0067] Neutral iridium dinuclear complex IrIr19: In a dry Schlenk tube, intermediate 1-e (0.05 g, 0.05 mmol), 2-mercaptothiazole (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed, and the mixture was evacuated and filled with nitrogen gas three times. Then, 10 mL of ethylene glycol ether was added using a nitrogen gas flow, and the mixture was stirred at 70°C for 24 hours. After cooling to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane. The mixture was concentrated, and dichloromethane:petroleum ether was passed through the column in a 5:1 ratio to obtain 36 mg of the yellow solid neutral iridium dinuclear complex IrIr19 in 40% yield. MALDI-TOF-MS (m / z): 1814.2 ([M] + ).

[0068] Example 20 Synthesis of neutral iridium dinuclear complex IrIr20 Synthetic route of the neutral iridium dinuclear complex IrIr20: [ka]

[0069] Neutral iridium dinuclear complex IrIr20: In a dry Schlenk tube, intermediate 1-f (0.05 g, 0.05 mmol), 2-mercaptothiazole (0.01 g, 0.06 mmol), and Na2CO3 (0.013 g, 0.11 mmol) were placed, and the tube was vacuumed and filled with nitrogen gas three times. Then, 10 mL of ethylene glycol ether was added using a nitrogen gas flow, and the reaction was stirred at 70°C for 24 hours. After cooling to room temperature, the organic phase was concentrated, water was added, and the mixture was extracted with dichloromethane, concentrated, and passed through a column with dichloromethane:petroleum ether in a 5:1 ratio to obtain 39 mg of the yellow solid neutral iridium dinuclear complex IrIr20 in 45% yield. MALDI-TOF-MS (m / z): 1718.2 ([M] + ).

[0070] Example 21: Manufacturing and Characterization of OLED Devices The manufacturing steps for an OLED device having ITO / PEDOT:PSS (40nm) / EML (80nm) / TPBi (30nm) / LiF (1nm) / Al (120nm) / cathode are as follows.

[0071] (i) The ITO surface was sonicated for 30 minutes using a 5% aqueous solution of Decon90 cleaning solution, then ultrasonically cleaned several times with deionized water, then ultrasonically cleaned with isopropanol, dried with nitrogen gas, and treated with oxygen gas plasma for 5 minutes to improve the work function of the ITO electrode.

[0072] (ii) A PEDOT:PSS solution was spin-coated onto an oxygen gas plasma-treated ITO glass substrate to obtain a 40 nm thin film. After spin-coating was complete, the film was annealed in air at 150°C for 20 minutes. PEDOT:PSS is an aqueous solution of a polymer, composed of two substances, PEDOT and PSS, where PEDOT is a polymer of 3,4-ethylenedioxythiophene monomer and PSS is polystyrene sulfonate.

[0073] (iii) First, PVK, PBD, and complexes (IrIr1 to IrIr20) were dissolved in toluene in a mass ratio of 65:30:5. This solution was spin-coated in a nitrogen gas glove box to obtain a thin film of 80 nm, and then annealed at 120°C for 10 minutes. PVK is an abbreviation for polyethylenecarbazol, and PBD is an abbreviation for (2-phenyl-5-(4-biphenylyl)-1,3,4-oxadiazole).

[0074] (iv) The spin-coated device was placed in a vacuum deposition chamber, and a light-emitting device was fabricated by sequentially depositing 30 nm TPBi, 1 nm LiF, and 100 nm aluminum. TPBi is an abbreviation for 1,3,5-tris(1-phenyl-1H-benzimidazole-2-yl)benzene. The current-voltage-luminance (JVL) characteristics of this OLED device were evaluated using an evaluation device, and important parameters such as efficiency and external quantum efficiency were recorded simultaneously. The maximum external quantum efficiency (EQE) of the OLED was detected to be 16%. Specifically, it was as follows:

[0075] Further optimizations, such as optimizing the device structure and the combination of hole transport material (HTM), electron transport material (ETM), and host material, have further enhanced the device's performance, particularly its efficiency, drive voltage, and lifespan.

Claims

1. A neutral iridium dinuclear complex, the general formula of which is shown in structure (I) or (II), 【Chemistry 25】 The formula described in Formula I or II 【Chemistry 26】 A is a bidentate ligand, and both coordinating atoms are A, wherein A is selected from a nitrogen atom or a phosphorus atom, and X as described in formula I or II is an oxygen atom or a sulfur atom, a neutral iridium dinuclear complex.

2. The neutral iridium dinuclear complex according to claim 1, characterized in that the neutral iridium dinuclear complex is selected from the following complexes IrIr1-IrIr10. 【Chemistry 27】 【change】

3. First, chloro(1,5-cyclooctadiene)iridium(I) (dimer) and biphenylene are used as starting materials, respectively. Under anhydrous and oxygen-free conditions, coordination between the dianionic ligand biphenyl and metallic iridium is achieved by oxidative addition, ultimately forming the precursor 1-a of the first step. Subsequently, the chlorine atom is removed under the action of silver trifluoromethanesulfonate, and then the neutral ligand is formed. 【Chemistry 28】 Step 1) involves a reciprocal reaction under mild conditions to obtain second-step complex precursors 1-b to 1-f, A method for producing a neutral iridium dinuclear complex according to claim 1 or 2, characterized by comprising step 2) reacting the complex precursor 1-b to 1-f prepared in step 1) with a sulfur-containing ligand under conditions of 60 to 90°C to ultimately obtain neutral iridium dinuclear complexes IrIr1 to IrIr20.

4. The method for producing a neutral iridium dinuclear complex according to claim 3, characterized in that the sulfur-containing ligand in step 2) includes one or more of 2-mercaptobenzthiazole, 2-mercaptobenzothiazole, or 2-mercaptoxazolyl.

5. Applications of the neutral iridium dinuclear complex according to claim 1 or 2 in the manufacture of organic electronic devices.

6. The application according to claim 5, characterized in that the organic electronic device is one or more of the following: organic light-emitting diode, organic solar cell, organic light-emitting cell, organic field-effect transistor, organic laser, organic spin-electron device, organic sensor, and organic plasmon light-emitting diode.

7. The application according to claim 5, characterized in that the mass concentration of the neutral iridium dinuclear complex in the matrix is ​​3 to 10 wt%.

8. An organic electronic device characterized by comprising the neutral iridium dinuclear complex described in claim 1 or 2.

9. The organic electronic device according to claim 8, characterized in that the mass concentration of the neutral iridium dinuclear complex is 310 wt%.

10. The organic electronic device according to claim 8, characterized in that the mass concentration of the neutral iridium dinuclear complex is 5 wt%.

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