Binuclear neutral iridium complex as well as preparation method and application thereof

Abstract

The invention discloses a binuclear neutral iridium complex, a preparation method thereof and application of the binuclear neutral iridium complex in preparation of organic electronic devices. The invention also relates to an organic electronic device, especially an organic light-emitting diode, comprising the binuclear-containing neutral iridium complex according to the invention, and application thereof in display and illumination technologies. By optimizing the structure of the device and changing the concentration of the binuclear neutral iridium 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 binuclear neutral iridium complex and a preparation method and application thereof, and in particular to an application in an organic light emitting diode. Background Art

[0002] Organic light-emitting diodes (OLEDs) have great potential for application in 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.

[0003] In 1999, Professor Thomson of the University of Southern California and Professor Forrest of Princeton University combined tris(2-phenylpyridine)iridium Ir(ppy) 3 Doping into N,N-dicarbazole biphenyl (CBP) has successfully prepared green electrophosphorescent devices, which has aroused people's strong interest in complex phosphorescent materials. The introduction of heavy metals improves the molecular spin-orbit coupling, shortens the phosphorescence lifetime, enhances the molecular intersystem crossing, and enables the smooth emission of phosphorescence. To date, the internal quantum efficiency of phosphorescent OLEDs has been close to 100%.

[0004] It is particularly worth mentioning that binuclear metal iridium complexes have two metal iridium centers, and their coordination modes are richer than those of mononuclear metal iridium complexes, which is more conducive to regulating and improving the overall luminescence properties of the complexes. Despite this, there are relatively few choices of bridging ligands connecting the two metal centers, and it is difficult to improve the luminescence properties of the complexes. Therefore, the selection of suitable bridging ligands is crucial to improving and regulating the optical properties of the complexes. In addition, how to design biphenyl ligands with strong field coordination effects into binuclear neutral metal iridium complexes is a major challenge. Summary of the invention

[0005] 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 binuclear neutral iridium complex with strong stability and luminescence performance.

[0006] The technical problem that the present invention needs to solve is to provide a method for preparing a binuclear neutral iridium complex.

[0007] The technical problem that the present invention needs to solve is to provide an application of binuclear neutral iridium complex in the preparation of organic electronic devices.

[0008] The final technical problem to be solved by the present invention is to provide an organic electronic device containing the binuclear neutral iridium complex.

[0009] Technical solution: The present invention provides a binuclear neutral iridium complex, the general formula of which is shown in structure (I) or (II):

[0010]

[0011] Wherein, the It is a bidentate ligand, and both coordinating atoms are A, which can be selected from nitrogen atoms or phosphorus atoms. In formula I or II, X is an oxygen or sulfur atom.

[0012] Wherein, the binuclear neutral iridium complex is selected from the following complexes IrIr1-IrIr20:

[0013]

[0014]

[0015]

[0016] The present invention also includes a method for preparing the binuclear neutral iridium complex, comprising the following steps:

[0017] 1) First, 1,5-cyclooctadiene iridium chloride dimer and biphenylene were used as raw materials, and the coordination of the double anion ligand biphenyl with metal iridium was achieved by oxidative addition reaction under anhydrous and oxygen-free conditions, and finally the first step precursor 1-a was formed; then, the chlorine atom was removed under the action of silver trifluoromethanesulfonate, and then reacted with the neutral ligand Under mild conditions, they react with each other to obtain the second-step complex precursor (1-b to 1-f);

[0018] 2) Then the complex precursor prepared in step 1) is reacted with a sulfur-containing ligand at 60-90° C. to finally obtain a binuclear neutral iridium complex (IrIr1-IrIr20).

[0019] Wherein, the sulfur-containing ligand in step 2) includes one or more of 2-mercaptobenzoxazole, 2-mercaptobenzothiazole or 2-mercaptooxazole.

[0020] The preferred temperature in step 2) is 70°C.

[0021] The present invention also includes the use of the binuclear neutral iridium complex in the preparation of organic electronic devices.

[0022] 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).

[0023] Wherein, the mass concentration of the binuclear neutral iridium complex in the matrix is ​​3-10wt%.

[0024] The present invention also includes an organic electronic device, which contains the binuclear neutral iridium complex.

[0025] Wherein, the mass concentration of the binuclear neutral iridium complex is 3-10wt%.

[0026] Preferably, the binuclear neutral iridium complex has a mass concentration of 5 wt %.

[0027] Beneficial effects: Compared with the prior art, the present invention has the following advantages: the novel binuclear neutral iridium complex prepared by the present invention not only has biphenyl ligands with strong field effect, but also has sulfur-containing ligands with strong rigidity and electronic effect, so it can effectively improve the stability of the compound, the luminescent performance and the performance of the corresponding device. The present invention also relates to organic electronic devices, especially organic light-emitting diodes, comprising the binuclear neutral metal iridium complex according to the present invention, and their application in display and lighting technology. By optimizing the device structure and changing the concentration of the binuclear neutral metal iridium complex in the matrix, the best device performance can be achieved, which is convenient for realizing high-efficiency, high-brightness and high-stability OLED devices, and provides a better material option for full-color display and lighting applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Picture 1 X-ray single crystal structure of binuclear neutral iridium complex IrIr1;

[0029] Picture 2 X-ray single crystal structure of the binuclear neutral iridium complex IrIr2. DETAILED DESCRIPTION

[0030] Example 1 Synthesis of binuclear neutral iridium complex IrIr1

[0031] Synthesis route of binuclear neutral iridium complex IrIr1:

[0032]

[0033] 1. Synthesis of intermediate 1-a:

[0034] 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 intermediate 1-a, with a yield of 85%. MALDI-TOF-MS (m / z): 976.1 ([M] + ).

[0035] 2. Synthesis of intermediate 1-b:

[0036] Place intermediate 1-a (0.10 g, 0.1 mmol), 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 yellow solid intermediate 1-b 0.06 g, yield 75%. ESI-MS (m / z): 609.2 ([M-OTf] + ).

[0037] 3. Binuclear neutral iridium complex IrIr1:

[0038] In a dry two-necked bottle were placed intermediate 1-b (0.04 g, 0.05 mmol), 2-mercaptobenzoxazole (0.01 g, 0.06 mmol), Na 2 CO 3 (0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° C for 24 hours, cooled to room temperature, concentrated the organic phase, then added water, extracted with dichloromethane, concentrated, and passed through a column with dichloromethane: petroleum ether = 5:1 to obtain an orange-red solid binuclear neutral iridium complex IrIr120 mg, with a yield of 30%. MALDI-TOF-MS (m / z): 1302.2 ([M] + ).

[0039] The single crystal of binuclear neutral iridium complex IrIr1 was obtained by slowly diffusing ethanol solvent into its dichloromethane solution. Its structure is shown in Picture 1 shown.

[0040] Example 2 Synthesis of binuclear neutral iridium complex IrIr2

[0041] Synthesis route of binuclear neutral iridium complex IrIr2:

[0042]

[0043] 1. Synthesis of intermediate 1-c:

[0044] Place intermediate 1-a (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 yellow solid intermediate 1-c 0.06 g, yield 75%. ESI-MS (m / z): 633.1 ([M-OTf] + ).

[0045] 2. Binuclear neutral iridium complex IrIr2:

[0046] In a dry two-necked bottle were placed intermediate 1-c (0.04 g, 0.05 mmol), 2-mercaptobenzoxazole (0.01 g, 0.06 mmol), Na 2 CO 3 (0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° 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 column with dichloromethane: petroleum ether = 5:1 to obtain an orange-red solid binuclear neutral iridium complex IrIr227 mg, with a yield of 40%. MALDI-TOF-MS (m / z): 1350.2 ([M] + ).

[0047] The single crystal of binuclear neutral iridium complex IrIr2 was obtained by slowly diffusing ethanol solvent into its dichloromethane solution. Its structure is shown in Picture 2 shown.

[0048] Example 3 Synthesis of binuclear neutral iridium complex IrIr3

[0049] Synthesis route of binuclear neutral iridium complex IrIr3:

[0050]

[0051] 1. Synthesis of intermediate 1-d:

[0052] In a dry Schlenck bottle, place 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), silver trifluoromethanesulfonate (0.06 g, 0.22 mmol), 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 yellow solid intermediate 1-d 0.07 g, yield 80%. ESI-MS (m / z): 684.8 ([M-OTf] + ).

[0053] 2. Binuclear neutral iridium complex IrIr3:

[0054] In a dry two-necked bottle, 1-d (0.04 g, 0.05 mmol), 2-mercaptobenzoxazole (0.01 g, 0.06 mmol), Na 2 CO 3 (0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° C for 24 hours, cooled to room temperature, concentrated the organic phase, then added water, extracted with dichloromethane, concentrated, and passed through a column with dichloromethane: petroleum ether = 5:1 to obtain 25 mg of an orange-red solid binuclear neutral iridium complex IrIr3, with a yield of 35%. MALDI-TOF-MS (m / z): 1454.3 ([M] + ).

[0055] Example 4 Synthesis of binuclear neutral iridium complex IrIr4

[0056] Synthesis route of binuclear neutral iridium complex IrIr4:

[0057]

[0058] 1. Synthesis of intermediate 1-e:

[0059] Place 1-a (0.10 g, 0.1 mmol), 1,2-bis(diphenylphosphino)benzene (0.09 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 yellow solid intermediate 1-e 0.08 g, yield 80%. ESI-MS (m / z): 899.2 ([M-OTf] +).

[0060] 2. Binuclear neutral iridium complex IrIr4:

[0061] In a dry two-necked bottle, 1-e (0.05 g, 0.05 mmol), 2-mercaptobenzoxazole (0.01 g, 0.06 mmol), Na 2 CO 3 (0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° C for 24 hours, cooled to room temperature, concentrated the organic phase, then added water, extracted with dichloromethane, concentrated, and passed through a column with dichloromethane: petroleum ether = 5:1 to obtain 38 mg of a yellow solid binuclear neutral iridium complex IrIr4, with a yield of 40%. MALDI-TOF-MS (m / z): 1882.3 ([M] + ).

[0062] Example 5 Synthesis of binuclear neutral iridium complex IrIr5

[0063] Synthesis route of binuclear neutral iridium complex IrIr5:

[0064]

[0065] Synthesis of intermediate 1-f:

[0066] Place 1-a (0.10 g, 0.1 mmol), 1,2-bis(diphenylphosphine)ethane (0.08 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 yellow solid intermediate 1-f 0.08 g, yield 80%. ESI-MS (m / z): 851.3 ([M-OTf] + ).

[0067] Binuclear neutral iridium complex IrIr5:

[0068] In a dry two-necked bottle, intermediate 1-f (0.05 g, 0.05 mmol), 2-mercaptobenzoxazole (0.01 g, 0.06 mmol), Na 2 CO 3(0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° C for 24 hours, cooled to room temperature, concentrated the organic phase, then added water, extracted with dichloromethane, concentrated, and passed through a column with dichloromethane: petroleum ether = 5:1 to obtain 38 mg of a yellow solid binuclear neutral iridium complex IrIr5, with a yield of 40%. MALDI-TOF-MS (m / z): 1786.3 ([M] + ).

[0069] Example 6 Synthesis of binuclear neutral iridium complex IrIr6

[0070] Synthesis route of binuclear neutral iridium complex IrIr6:

[0071]

[0072] Binuclear neutral iridium complex IrIr6:

[0073] In a dry two-necked bottle were placed intermediate 1-b (0.04 g, 0.05 mmol), 2-mercaptobenzothiazole (0.01 g, 0.06 mmol), Na 2 CO 3 (0.013 g, 0.11 mmol), vacuum and nitrogen gas were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° C for 24 hours, cooled to room temperature, concentrated the organic phase, then added water, extracted with dichloromethane, concentrated, and passed through a column with dichloromethane: petroleum ether = 5:1 to obtain an orange-red solid binuclear neutral iridium complex IrIr630 mg, with a yield of 45%. MALDI-TOF-MS (m / z): 1334.3 ([M] + ).

[0074] Example 7 Synthesis of binuclear neutral iridium complex IrIr7

[0075] Synthesis route of binuclear neutral iridium complex IrIr7:

[0076]

[0077] Binuclear neutral iridium complex IrIr7:

[0078] In a dry two-necked bottle were placed intermediate 1-c (0.04 g, 0.05 mmol), 2-mercaptobenzothiazole (0.01 g, 0.06 mmol), Na 2 CO 3(0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° 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 column with dichloromethane: petroleum ether = 5:1 to obtain an orange-red solid binuclear neutral iridium complex IrIr728 mg, with a yield of 40%. MALDI-TOF-MS (m / z): 1383.1 ([M+1] + ).

[0079] Example 8 Synthesis of binuclear neutral iridium complex IrIr8

[0080] Synthesis route of binuclear neutral iridium complex IrIr8:

[0081]

[0082] Binuclear neutral iridium complex IrIr8:

[0083] In a dry two-necked bottle were placed intermediate 1-d (0.04 g, 0.05 mmol), 2-mercaptobenzothiazole (0.01 g, 0.06 mmol), Na 2 CO 3 (0.013 g, 0.11 mmol), vacuum and nitrogen gas were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° C for 24 hours, cooled to room temperature, concentrated the organic phase, then added water, extracted with dichloromethane, concentrated, and passed through a column with dichloromethane: petroleum ether = 5:1 to obtain an orange-red solid binuclear neutral iridium complex IrIr822 mg, with a yield of 30%. MALDI-TOF-MS (m / z): 1486.2 ([M] + ).

[0084] Example 9 Synthesis of binuclear neutral iridium complex IrIr9

[0085] Synthesis route of binuclear neutral iridium complex IrIr9:

[0086]

[0087] Binuclear neutral iridium complex IrIr9:

[0088] In a dry two-necked bottle, intermediate 1-e (0.05 g, 0.05 mmol), 2-mercaptobenzothiazole (0.01 g, 0.06 mmol), Na 2 CO 3(0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° C for 24 hours, cooled to room temperature, concentrated the organic phase, then added water, extracted with dichloromethane, concentrated, and passed through a column with dichloromethane: petroleum ether = 5:1 to obtain 38 mg of a yellow solid binuclear neutral iridium complex IrIr9, with a yield of 40%. MALDI-TOF-MS (m / z): 1914.3 ([M] + ).

[0089] Example 10 Synthesis of binuclear neutral iridium complex IrIr10

[0090] Synthesis route of binuclear neutral iridium complex IrIr10:

[0091]

[0092] Binuclear neutral iridium complex IrIr10:

[0093] In a dry two-necked bottle, intermediate 1-f (0.05 g, 0.05 mmol), 2-mercaptobenzothiazole (0.01 g, 0.06 mmol), Na 2 CO 3 (0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° C for 24 hours, cooled to room temperature, concentrated the organic phase, then added water, extracted with dichloromethane, concentrated, and passed through a column with dichloromethane: petroleum ether = 5:1 to obtain 32 mg of a yellow solid binuclear neutral iridium complex IrIr10, with a yield of 35%. MALDI-TOF-MS (m / z): 1818.3 ([M] + ).

[0094] Example 11 Synthesis of binuclear neutral iridium complex IrIr11

[0095] Synthesis route of binuclear neutral iridium complex IrIr11:

[0096]

[0097] Binuclear neutral iridium complex IrIr11:

[0098] In a dry two-necked bottle were placed intermediate 1-b (0.04 g, 0.05 mmol), 2-mercaptooxazole (0.01 g, 0.06 mmol), Na 2 CO 3(0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° C for 24 hours, cooled to room temperature, concentrated the organic phase, then added water, extracted with dichloromethane, concentrated, and passed through a column with dichloromethane: petroleum ether = 5:1 to obtain an orange-red solid binuclear neutral iridium complex IrIr11 18 mg, with a yield of 30%. MALDI-TOF-MS (m / z): 1202.2 ([M] + ).

[0099] Example 12 Synthesis of binuclear neutral iridium complex IrIr12

[0100] Synthesis route of binuclear neutral iridium complex IrIr12:

[0101]

[0102] Binuclear neutral iridium complex IrIr12:

[0103] In a dry two-necked bottle were placed intermediate 1-c (0.04 g, 0.05 mmol), 2-mercaptooxazole (0.01 g, 0.06 mmol), Na 2 CO 3 (0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° C for 24 hours, cooled to room temperature, concentrated the organic phase, then added water, extracted with dichloromethane, concentrated, and passed through a column with dichloromethane: petroleum ether = 5:1 to obtain 26 mg of an orange-red solid binuclear neutral iridium complex IrIr12, with a yield of 42%. MALDI-TOF-MS (m / z): 1250.1 ([M] + ).

[0104] Example 13 Synthesis of binuclear neutral iridium complex IrIr13

[0105] Synthesis route of binuclear neutral iridium complex IrIr13:

[0106]

[0107] Binuclear neutral iridium complex IrIr13:

[0108] In a dry two-necked bottle were placed intermediate 1-d (0.04 g, 0.05 mmol), 2-mercaptooxazole (0.01 g, 0.06 mmol), Na 2 CO 3(0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° 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 column with dichloromethane: petroleum ether = 5:1 to obtain 26 mg of an orange-red solid binuclear neutral iridium complex IrIr13, with a yield of 38%. MALDI-TOF-MS (m / z): 1354.1 ([M] + ).

[0109] Example 14 Synthesis of binuclear neutral iridium complex IrIr14

[0110] Synthesis route of binuclear neutral iridium complex IrIr14:

[0111]

[0112] Binuclear neutral iridium complex IrIr14:

[0113] In a dry two-necked bottle were placed intermediate 1-e (0.05 g, 0.05 mmol), 2-mercaptooxazole (0.01 g, 0.06 mmol), Na 2 CO 3 (0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° C for 24 hours, cooled to room temperature, concentrated the organic phase, then added water, extracted with dichloromethane, concentrated, and passed through a column with dichloromethane: petroleum ether = 5:1 to obtain 37 mg of a yellow solid binuclear neutral iridium complex IrIr14, with a yield of 42%. MALDI-TOF-MS (m / z): 1782.3 ([M] + ).

[0114] Example 15 Synthesis of binuclear neutral iridium complex IrIr15

[0115] Synthesis route of binuclear neutral iridium complex IrIr15:

[0116]

[0117] Binuclear neutral iridium complex IrIr15:

[0118] In a dry two-necked bottle, intermediate 1-f (0.05 g, 0.05 mmol), 2-mercaptooxazole (0.01 g, 0.06 mmol), Na 2 CO 3(0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° 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 column with dichloromethane: petroleum ether = 5:1 to obtain 34 mg of a yellow solid binuclear neutral iridium complex IrIr15, with a yield of 40%. MALDI-TOF-MS (m / z): 1686.3 ([M] + ).

[0119] Example 16 Synthesis of binuclear neutral iridium complex IrIr16

[0120] Synthesis route of binuclear neutral iridium complex IrIr16:

[0121]

[0122] Binuclear neutral iridium complex IrIr16:

[0123] In a dry two-necked bottle, intermediate 1-b (0.04 g, 0.05 mmol), 2-mercaptothiazole (0.01 g, 0.06 mmol), Na 2 CO 3 (0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° 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 column with dichloromethane: petroleum ether = 5:1 to obtain 22 mg of an orange-red solid binuclear neutral iridium complex IrIr16, with a yield of 35%. MALDI-TOF-MS (m / z): 1234.1 ([M] + ).

[0124] Example 17 Synthesis of binuclear neutral iridium complex IrIr17

[0125] Synthesis route of binuclear neutral iridium complex IrIr17:

[0126]

[0127] Binuclear neutral iridium complex IrIr17:

[0128] In a dry two-necked bottle were placed intermediate 1-c (0.04 g, 0.05 mmol), 2-mercaptothiazole (0.01 g, 0.06 mmol), Na 2 CO 3(0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ethyl ether was added under nitrogen flow, stirred at 70 ° C for 24 hours, cooled to room temperature, concentrated the organic phase, then added water, extracted with dichloromethane, concentrated, and passed through a column with dichloromethane: petroleum ether = 5:1 to obtain 26 mg of an orange-red solid binuclear neutral iridium complex IrIr17, with a yield of 40%. MALDI-TOF-MS (m / z): 1282.1 ([M] + ).

[0129] Example 18 Synthesis of binuclear neutral iridium complex IrIr18

[0130] Synthesis route of binuclear neutral iridium complex IrIr18:

[0131]

[0132] Binuclear neutral iridium complex IrIr18:

[0133] In a dry two-necked bottle were placed intermediate 1-d (0.04 g, 0.05 mmol), 2-mercaptothiazole (0.01 g, 0.06 mmol), Na 2 CO 3 (0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° C for 24 hours, cooled to room temperature, concentrated the organic phase, then added water, extracted with dichloromethane, concentrated, and passed through a column with dichloromethane: petroleum ether = 5:1 to obtain 26 mg of an orange-red solid binuclear neutral iridium complex IrIr18, with a yield of 38%. MALDI-TOF-MS (m / z): 1386.1 ([M] + ).

[0134] Example 19 Synthesis of binuclear neutral iridium complex IrIr19

[0135] Synthesis route of binuclear neutral iridium complex IrIr19:

[0136]

[0137] Binuclear neutral iridium complex IrIr19:

[0138] In a dry two-necked bottle, intermediate 1-e (0.05 g, 0.05 mmol), 2-mercaptothiazole (0.01 g, 0.06 mmol), Na 2 CO 3(0.013 g, 0.11 mmol), vacuum and nitrogen gas were cycled three times, then 10 mL of ethylene glycol ethyl ether was added under nitrogen flow, stirred at 70 ° C for 24 hours, cooled to room temperature, concentrated the organic phase, then added water, extracted with dichloromethane, concentrated, and passed through a column with dichloromethane: petroleum ether = 5:1 to obtain 36 mg of a yellow solid binuclear neutral iridium complex IrIr19, with a yield of 40%. MALDI-TOF-MS (m / z): 1814.2 ([M] + ).

[0139] Example 20 Synthesis of binuclear neutral iridium complex IrIr20

[0140] Synthesis route of binuclear neutral iridium complex IrIr20:

[0141]

[0142] Binuclear neutral iridium complex IrIr20:

[0143] In a dry two-necked bottle, intermediate 1-f (0.05 g, 0.05 mmol), 2-mercaptothiazole (0.01 g, 0.06 mmol), Na 2 CO 3 (0.013 g, 0.11 mmol), vacuum and nitrogen were cycled three times, then 10 mL of ethylene glycol ether was added under nitrogen flow, stirred at 70 ° C for 24 hours, cooled to room temperature, concentrated the organic phase, then added water, extracted with dichloromethane, concentrated, and passed through a column with dichloromethane: petroleum ether = 5:1 to obtain 39 mg of a yellow solid binuclear neutral iridium complex IrIr20, with a yield of 45%. MALDI-TOF-MS (m / z): 1718.2 ([M] + ).

[0144] Example 21 Preparation and Characterization of OLED Devices

[0145] The preparation steps of the OLED device with ITO / PEDOT:PSS (40nm) / EML (80nm) / TPBi (30nm) / LiF (1nm) / Al (120nm) / cathode are as follows:

[0146] (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, and drying with nitrogen; treating under oxygen plasma for 5 minutes to clean the ITO surface and improve the work function of the ITO electrode;

[0147] (ii) Spin coating a PEDOT:PSS solution on an ITO glass substrate treated with oxygen plasma to obtain a 40 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.

[0148] (iii) PVK, PBD, and complexes (IrIr1 to IrIr20) were first dissolved in toluene at a mass ratio of 65:30:5, and the solution was spin-coated in a nitrogen glove box to obtain an 80 nm film, which was then annealed at 120° C. for 10 minutes. PVK is the abbreviation of polyvinyl carbazole, and PBD is the abbreviation of 2-(4-tert-butylphenyl)-5-biphenyloxadiazole.

[0149] (iv) Place the spin-coated device into a vacuum evaporation chamber, and sequentially evaporate 30nm TPBi, 1nm LiF and 100nm aluminum to obtain a light-emitting device. TPBi is the abbreviation of 1,3,5-tri(1-phenyl-1H-benzimidazol-2-yl)benzene. The current-voltage-luminance (JVL) characteristics of the OLED device are characterized by a characterization device, 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 the OLED is 16%. The details are as follows:

[0150] Complex IrIr1 IrIr2 IrIr3 IrIr4 IrIr5 IrIr6 IrIr7 IrIr8 IrIr9 IrIr10 EQE 9.2％ 10.8％ 9.5％ 12.5％ 13％ 8.8％ 9.5％ 10.5％ 16％ 14％ Complex IrIr11 IrIr12 IrIr13 IrIr14 IrIr15 IrIr16 IrIr17 IrIr18 IrIr19 IrIr20 EQE 7.8％ 9.5％ 8.8％ 12％ 11.5％ 8％ 9％ 8.5％ 15.5％ 12.5％

[0151] 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 binuclear neutral iridium complex, the general formula of which is shown in structure (I) or (II): in, Described in formula I or II It is a bidentate ligand, and the two coordinating atoms are both A, wherein A is selected from a nitrogen atom or a phosphorus atom, and X in Formula I or II is an oxygen or sulfur atom.

2. The binuclear neutral iridium complex according to claim 1, characterized in that The binuclear neutral iridium complex is selected from the following complexes IrIr1-IrIr10:

3. The method for preparing the binuclear neutral iridium complex according to claim 1 or 2, characterized in that: The following steps are involved: 1) First, 1,5-cyclooctadiene iridium chloride dimer and biphenylene were used as raw materials, and the coordination of the double anion ligand biphenyl with metal iridium was achieved by oxidative addition reaction under anhydrous and oxygen-free conditions, and finally the first step precursor 1-a was formed; then, the chlorine atom was removed under the action of silver trifluoromethanesulfonate, and then reacted with the neutral ligand Under mild conditions, they react with each other to obtain the second-step complex precursors 1-b to 1-f; 2) reacting the complex precursors 1-b to 1-f prepared in step 1) with a sulfur-containing ligand at 60 to 90° C. to obtain binuclear neutral iridium complexes IrIr1 to IrIr20.

4. The method for preparing a binuclear neutral iridium complex according to claim 3, characterized in that: The sulfur-containing ligand in step 2) includes one or more of 2-mercaptobenzoxazole, 2-mercaptobenzothiazole or 2-mercaptooxazole.

5. Use of the binuclear neutral iridium complex according to claim 1 or 2 in the preparation of organic electronic devices.

6. The use according to claim 5, characterized in that: The organic electronic device is 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 and an organic plasmon emission diode.

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

8. An organic electronic device, characterized in that: The organic electronic device comprises the binuclear neutral iridium complex according to claim 1 or 2.

9. The organic electronic device according to claim 8, characterized in that: The mass concentration of the binuclear neutral iridium complex is 3-10wt%.

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

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