Neutral iridium complex containing phenyl thiophene coordination as well as preparation method and application of neutral iridium complex

Abstract

The invention discloses a neutral iridium complex containing phenyl thiophene coordination as well as a preparation method and application thereof, and particularly relates to application in an organic light-emitting diode. The invention also relates to an organic electronic device, especially an organic light-emitting diode, comprising the neutral metal iridium complex containing phenyl thiophene coordination according to the invention, 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 neutral metal iridium complex containing the phenyl thiophene coordination 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] This invention belongs to the field of new materials technology, specifically relating to a neutral iridium complex containing phenylthiophene coordination, its preparation method and application, and particularly its application in organic light-emitting diodes. Background Technology

[0002] Organic light-emitting diodes (OLEDs) hold great potential for applications in optoelectronic devices such as flat panel displays and lighting due to the versatility of organic semiconductor materials in synthesis, relatively low manufacturing costs, and excellent optical and electrical properties. To improve the luminous efficiency of OLEDs, various fluorescent and phosphorescent luminescent material systems have been developed. OLEDs using fluorescent materials exhibit high reliability, but their internal electroluminescence quantum efficiency under electric field excitation is limited to 25% because the probability ratio of excitons generating singlet and triplet excited states is 1:3.

[0003] In 1999, Professor Thomson of the University of Southern California and Professor Forrest of Princeton University successfully fabricated green electrophosphorescent devices by doping tris(2-phenylpyridine)iridium Ir(ppy)3 into N,N-dicarbazole biphenyl (CBP), which sparked great interest in complex phosphorescent materials. The introduction of heavy metals improved molecular spin-orbit coupling, shortened phosphorescence lifetime, and enhanced intersystem crossing, enabling successful phosphorescence emission. To date, the internal quantum efficiency of phosphorescent OLEDs has approached 100%.

[0004] Nevertheless, most neutral phosphorescent iridium complexes consist of three monoanionic (-1, -1, -1) bidentate ligands (such as the Ir(ppy)3 structure, where ppy is a monoanionic ligand). Neutral phosphorescent iridium complexes composed of three-charge (0, -1, -2) ligands (neutral ligands, monoanionic ligands, and dianionic ligands) are less common, especially iridium complexes composed of dianionic ligands with two aryl carbon groups, which are even less developed due to their difficult synthesis. Since phenylthiophene has two strongly field-coordinated carbon atoms, it can enhance the stability of the complex to some extent and improve the spin-orbit coupling (SOC) effect. However, coordinating phenylthiophene with metallic iridium to ultimately form phosphorescent iridium complexes with three-charge (0, -1, -2) ligands presents a significant challenge.

[0005] To further improve the performance of this type of iridium complex material and broaden the selection range of such materials, iridium complex materials with phenylthiophene coordination urgently need to be developed. Summary of the Invention

[0006] Purpose of the invention: The purpose of this invention is to provide a class of iridium complexes containing phenylthiophene ligands with high stability and good luminescence performance.

[0007] A second objective of this invention is to provide a method for preparing iridium complexes containing phenylthiophene ligands.

[0008] A third objective of this invention is to provide applications of the aforementioned iridium complex containing phenylthiophene ligands.

[0009] Technical solution: This invention provides a neutral iridium complex containing phenylthiophene coordination, the structural formula of which is shown in (I): ,in, It is a bidentate monoanion ligand. It is a bidentate neutral ligand.

[0010] in, When appearing multiple times, they can be independently selected from any of the following general formulas L1 to L15, wherein R3 to R72 are selected from -H, -F, -Cl, Br, I, -D, -CN, -NO2, -CF3, B(OR2)2, Si(R2)3, straight-chain alkanes, alkane ethers, alkane thioethers containing 1 to 10 carbon atoms, branched alkanes, cycloalkanes, alkane ethers or alkane thioethers containing 3 to 10 carbon atoms, hydrogen groups or aryl groups containing 6 to 10 carbon atoms, wherein the dashed line represents the bond directly connected to the metal element iridium;

[0011] in, When they appear multiple times, they can be independently selected from any of the following general formulas N1 to N8: Wherein, R1 is selected from -H, -F, -Cl, -Br, -I, -D, -CN, -NO2, -CF3, -OCH3, tert-butyl, substituted or unsubstituted carbazole, substituted or unsubstituted diphenylamino, the dashed line represents the bond directly connected to the metal element iridium, x is any integer from 0 to 2, y is any integer from 0 to 4, z is any integer from 0 to 3, and u is any integer from 0 to 5.

[0012] Its general formula is shown in the following structure: in, It is a bidentate monoanion ligand, and R is selected from one or more of hydrogen, tert-butyl or methoxy.

[0013] The neutral iridium complex is selected from the following complexes Ir1-Ir20: .

[0014] This invention provides a method for preparing the aforementioned neutral iridium complex containing phenylthiophene coordination, comprising the following steps: 1) First, 3,4-dibromothiophene was used as a raw material and 2-bromophenylboronic acid was reacted with it via a Suzuki coupling reaction to form intermediate 1a. Then, bromine was removed by n-butyllithium at a low temperature of -78°C, and then intermediate 1b was formed under the action of copper chloride. 2) Then, using 1,5-cyclooctadiene iridium chloride dimer and intermediate 1b prepared in step 1) as raw materials, under anhydrous and oxygen-free conditions, the coordination of the dianionic ligand phenylthiophene with metallic iridium is achieved by oxidative addition reaction, finally forming the first-step precursor 1c; then, under the action of silver trifluoromethanesulfonate, the chlorine atom is removed, and then it reacts with neutral ligands (2,2'-bipyridine, 4,4'-di-tert-butyl-2,2-bipyridine, 4,4'-dimethoxy-2,2'-bipyridine, 1,10-phenanthroline, 1,2-bis(diphenylphosphine)benzene) under mild conditions to obtain the second-step complex precursors; 3) Finally, the complex precursor prepared in step 2) can be reacted with monoanionic ligands (acetylacetone, 2,2,6,6-tetramethyl-3,5-heptadecylone, dibenzoylmethane, 2-phenylpyridine) under a high temperature and alkaline environment to obtain the corresponding neutral iridium complexes.

[0015] This invention provides the application of the aforementioned neutral iridium complex containing phenylthiophene coordination in the preparation of organic electronic devices.

[0016] The organic electronic device is one or more of the following: organic light-emitting diode, organic photovoltaic cell, organic light-emitting cell, organic field-effect transistor, organic laser, organic spintronic device, organic sensor, and organic plasmon emitter diode.

[0017] The mass concentration of the neutral iridium complex containing phenylthiophene coordination in the matrix is ​​1~10 wt%.

[0018] An organic electronic device comprising a neutral iridium complex containing phenylthiophene coordination as described in any one of claims 1 to 5, wherein, preferably, the mass concentration of the neutral iridium complex containing phenylthiophene coordination is 1 to 10 wt%.

[0019] The organic electronic devices include 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 spintronic devices, organic sensors, and organic plasmon emitting diodes.

[0020] This invention first prepares benzocyclobutene[1,2-c]thiophene, then uses an oxidative addition reaction to achieve coordination between the dianionic ligand phenylthiophene and metallic iridium. Next, chlorine atoms are removed under the action of silver trifluoromethanesulfonate, followed by coordination of a neutral ligand. Finally, coordination of a monoanionic ligand is achieved under a high-temperature alkaline environment, resulting in the successful preparation of a series of novel neutral iridium complexes containing phenylthiophene coordination. Because the phenylthiophene ligands in these complexes contain two coordinating carbon atoms with a strong field effect, the stability, luminescent properties, and performance of corresponding devices can be effectively improved.

[0021] Beneficial Effects: Compared with the prior art, the present invention has the following advantages: The phenylthiophene ligand contained in the novel iridium complex prepared by the present invention has two coordinating carbon atoms with a strong field effect, thus effectively improving the stability of the compound, its luminescent properties, and the performance of the corresponding device. The present invention also relates to organic electronic devices comprising the phenylthiophene-coordinated neutral metal iridium complex according to the present invention, particularly organic light-emitting diodes (OLEDs), and their applications in display and lighting technologies. By optimizing the device structure and changing the concentration of the phenylthiophene-coordinated neutral metal iridium complex in the matrix, optimal device performance can be achieved, facilitating the realization of high-efficiency, high-brightness, and high-stability OLED devices, and providing better material options for full-color display and lighting applications. Attached Figure Description

[0022] Figure 1 Synthetic route diagram for Ir1, a neutral iridium complex containing phenylthiophene coordination; Figure 2 Synthetic route diagram for Ir2, a neutral iridium complex containing phenylthiophene coordination; Figure 3 Synthetic route diagram for Ir3, a neutral iridium complex containing phenylthiophene coordination; Figure 4 Synthetic route diagram for Ir4, a neutral iridium complex containing phenylthiophene coordination; Figure 5 Synthetic route diagram for Ir5, a neutral iridium complex containing phenylthiophene coordination; Figure 6 Synthetic route diagram for Ir6, a neutral iridium complex containing phenylthiophene coordination; Figure 7Synthetic route diagram for Ir7, a neutral iridium complex containing phenylthiophene coordination; Figure 8 Synthetic route diagram for Ir8, a neutral iridium complex containing phenylthiophene coordination; Figure 9 Synthetic route diagram for Ir9, a neutral iridium complex containing phenylthiophene coordination; Figure 10 Synthetic route diagram for Ir10, a neutral iridium complex containing phenylthiophene coordination; Figure 11 Synthetic route diagram for Ir11, a neutral iridium complex containing phenylthiophene coordination; Figure 12 Synthetic route diagram for Ir12, a neutral iridium complex containing phenylthiophene coordination; Figure 13 Synthetic route diagram for Ir13, a neutral iridium complex containing phenylthiophene coordination; Figure 14 Synthetic route diagram for Ir14, a neutral iridium complex containing phenylthiophene coordination; Figure 15 Synthetic route diagram for Ir15, a neutral iridium complex containing phenylthiophene coordination; Figure 16 Synthetic route diagram for Ir16, a neutral iridium complex containing phenylthiophene coordination; Figure 17 Synthetic route diagram for Ir17, a neutral iridium complex containing phenylthiophene coordination; Figure 18 Synthetic route diagram for Ir18, a neutral iridium complex containing phenylthiophene coordination; Figure 19 Synthetic route diagram for Ir19, a neutral iridium complex containing phenylthiophene coordination; Figure 20 Synthetic route diagram for Ir20, a neutral iridium complex containing phenylthiophene coordination; Figure 21 X-ray single-crystal structure of Ir13, a neutral iridium complex coordinated with biphenyl derivatives; Figure 22 X-ray single-crystal structure of Ir15, a neutral iridium complex coordinated with biphenyl derivatives. Detailed Implementation

[0023] Example 1: Synthesis of Ir1, a neutral iridium complex with phenylthiophene coordination The synthetic route for the neutral iridium complex Ir1 with phenylthiophene coordination is as follows: Figure 1 .

[0024] 1. Synthetic intermediate 1a: In a dry double-necked flask, 3,4-dibromothiophene (1.01 g, 4.16 mmol), 2-bromophenylboronic acid (0.92 g, 4.59 mmol), tetra(triphenylphosphine)palladium (0.26 mg, 0.225 mmol), and sodium carbonate (0.57 g, 5.37 mmol) were placed. The mixture was evacuated and purged with nitrogen three times. Then, under nitrogen protection, 1,4-dioxane (9 mL) and water (3 mL) were added. The mixture was stirred at 100 °C for 6 hours. After the reaction was complete, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was extracted with dichloromethane. The organic phase was concentrated and purified by column chromatography with petroleum ether to give 0.89 g of a colorless oily liquid intermediate 1a, with a yield of 67%. MALDI-TOF-MS ( m / z ): 318.1 ([M] + 1.78 g of intermediate 1a was synthesized under the same reaction conditions and preparation steps.

[0025] 2. Synthetic intermediate 1b: Intermediate 1a (1.27 g, 4 mmol) was added to a dry Schlenck tube, evacuated and purged with nitrogen three times, then 20 mL of dry tetrahydrofuran was added under nitrogen protection. After stirring at room temperature for 5 minutes, the tube was transferred to -78°C and added... n BuLi (n-butyllithium, 4 mL, 10 mmol, 2.5 M) and CuCl2 (1.9 g, 14.07 mmol) were stirred for 1 h, then transferred to room temperature and stirred overnight. After the reaction was complete, the mixture was quenched with aqueous NH4Cl solution, extracted with ethyl acetate, the organic phases were combined and concentrated, and then column chromatography with petroleum ether was used to give a white solid, which was intermediate 1b, 0.2 g, yield 32%. MALDI-TOF-MS ( m / z ): 158.2 ([M] + ).

[0026] 3. Synthetic intermediate 1c: In a dry, double-necked flask, place 1,5-cyclooctadiene iridium chloride dimer (CAS No.: 12112-67-3, 0.88 g, 1.30 mmol) and intermediate 1b (0.41 g, 2.61 mmol). Vacuum the flask, purge with nitrogen, and circulate the solution three times. Then add 5 mL of dry dichloromethane and heat to 90°C. o The reaction mixture was stirred at C for 6 hours, cooled to room temperature, and then subjected to ultrasonic cleaning with approximately 20 mL of dichloromethane. Finally, it was filtered to obtain a dark green solid, which was intermediate 1c, 0.96 g, with a yield of 70%. MALDI-TOF-MS ( m / z ): 988.3([M] + ).

[0027] 4. Synthetic intermediate 1d: In a dry Schlenk flask, intermediate 1c (0.06 g, 0.06 mmol), 2,2'-bipyridine (0.02 g, 0.12 mmol), and silver trifluoromethanesulfonate (0.03 g, 0.13 mmol) were placed. The mixture was evacuated and purged with nitrogen three times. Then, 20 mL of dry dichloromethane was added under a nitrogen stream. The mixture was stirred at room temperature for 6 hours, filtered, and the filtrate was concentrated to 1 mL. A large amount of petroleum ether was then added to precipitate the solid. The solid was filtered and dried to obtain a yellow solid, which was intermediate 1d, 0.08 g, yield 85%. ESI-MS ( m / z ): 614.7 ([M-OTf] + ).

[0028] 5. Synthesis of Ir1, a neutral iridium complex coordinated with phenylthiophene: In a dry double-necked flask, place intermediate 1d (0.04 g, 0.05 mmol), acetylacetone (7.5 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol). Vacuum the flask, purge with nitrogen, and circulate the solution three times. Then, under a nitrogen flow, add 10 mL of ethylene glycol monoethyl ether. o The reaction was stirred and refluxed at C for 24 hours, cooled to room temperature, and the organic phase was concentrated. Water was then added, followed by extraction with dichloromethane, concentration, and column chromatography with dichloromethane to obtain a red solid, which was the neutral iridium complex Ir1 containing phenylthiophene coordination, 6.3 mg, in 20% yield. MALDI-TOF-MS ( m / z ): 605.7 ([M] + ).

[0029] Example 2 Synthesis of a neutral iridium complex Ir2 containing phenylthiophene coordination The synthetic route for the neutral iridium complex Ir2 containing phenylthiophene coordination is as follows: Figure 2 As shown.

[0030] Synthesis of the phenylthiophene-coordinated neutral iridium complex Ir2: Intermediate 1d (0.04 g, 0.05 mmol), 2,2,6,6-tetramethyl-3,5-heptadecane (13.8 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed in a dry two-necked flask. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under a nitrogen stream. The mixture was stirred and refluxed at 100 °C for 24 hours. After cooling to room temperature, the organic phase was concentrated, followed by the addition of water. The mixture was extracted with dichloromethane, concentrated, and column-sected with dichloromethane to obtain a red solid, which was the phenylthiophene-coordinated neutral iridium complex Ir2, 10.4 mg, in 30% yield. MALDI-TOF-MS ( m / z ): 689.9([M] + ).

[0031] Example 3 Synthesis of a neutral iridium complex Ir3 containing phenylthiophene coordination The synthetic route for the neutral iridium complex Ir3 containing phenylthiophene coordination is as follows: Figure 3 As shown.

[0032] Synthesis of the phenylthiophene-coordinated neutral iridium complex Ir3: Intermediate 1d (0.04 g, 0.05 mmol), benzoylmethane (16.8 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed in a dry two-necked flask. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under a nitrogen stream. The mixture was stirred and refluxed at 100 °C for 24 hours. After cooling to room temperature, the organic phase was concentrated, followed by the addition of water. The mixture was extracted with dichloromethane, concentrated, and column-sected with dichloromethane to obtain a red solid, which was the phenylthiophene-coordinated neutral iridium complex Ir3, 10.2 mg, with a yield of 28%. MALDI-TOF-MS ( m / z ): 729.3 ([M] + ).

[0033] Example 4 Synthesis of Ir4, a neutral iridium complex containing phenylthiophene coordination The synthetic route for the neutral iridium complex Ir4, which contains phenylthiophene coordination, is as follows: Figure 4 As shown.

[0034] Synthesis of the phenylthiophene-coordinated neutral iridium complex Ir4: Intermediate 1d (0.04 g, 0.05 mmol), 2-phenylpyridine (16.6 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed in a dry two-necked flask. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under a nitrogen stream. The mixture was stirred and refluxed at 100 °C for 24 hours. After cooling to room temperature, the organic phase was concentrated, followed by the addition of water. The mixture was extracted with dichloromethane, concentrated, and column-sected with dichloromethane to obtain a red solid, which was the phenylthiophene-coordinated neutral iridium complex Ir4, 11.6 mg, in 35% yield. MALDI-TOF-MS ( m / z ): 660.1 ([M] + ).

[0035] Example 5: Synthesis of Ir5, a neutral iridium complex coordinated with phenylthiophene. The synthetic route for the neutral iridium complex Ir5, which contains phenylthiophene coordination, is as follows: Figure 5 As shown.

[0036] 1. Synthetic intermediate 2d: In a dry Schlenk flask, intermediate 1c (0.06 g, 0.06 mmol), 4,4'-di-tert-butyl-2,2-bipyridine (0.03 g, 0.12 mmol), and silver trifluoromethanesulfonate (0.03 g, 0.13 mmol) were placed. The mixture was evacuated and purged with nitrogen three times. Then, 20 mL of dry dichloromethane was added under a nitrogen stream. The mixture was stirred at room temperature for 6 hours, filtered, and the filtrate was concentrated to 1 mL. A large amount of petroleum ether was then added to precipitate the solid. The solid was filtered and dried to obtain a yellow solid, which was intermediate 2d, yielding 84 mg (80% yield). MALDI-TOF-MS ( m / z ): 727.3 ([M-OTf] + ).

[0037] 2. Synthesis of Ir5, a neutral iridium complex coordinated with phenylthiophene: In a dry double-necked flask, place intermediate 2d (43 mg, 0.05 mmol), acetylacetone (7.5 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol). Vacuum the flask, purge with nitrogen, and circulate the solution three times. Then, under a nitrogen flow, add 10 mL of ethylene glycol monoethyl ether. oThe reaction was stirred and refluxed at C for 24 hours, cooled to room temperature, and the organic phase was concentrated. Water was then added, followed by extraction with dichloromethane, concentration, and column chromatography with dichloromethane to obtain a red solid, which was the neutral iridium complex Ir5 containing phenylthiophene coordination, 9.0 mg, in 25% yield. MALDI-TOF-MS ( m / z ): 717.9 ([M] + ).

[0038] Example 6: Synthesis of Ir6, a neutral iridium complex with phenylthiophene coordination The synthetic route for the neutral iridium complex Ir6, containing phenylthiophene coordination, is as follows: Figure 6 As shown.

[0039] Synthesis of the phenylthiophene-coordinated neutral iridium complex Ir6: Intermediate 2d (43 mg, 0.05 mmol), 2,2,6,6-tetramethyl-3,5-heptadecane (13.8 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed in a dry two-necked flask. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under a nitrogen stream. The mixture was stirred and refluxed at 100 °C for 24 hours. After cooling to room temperature, the organic phase was concentrated, followed by the addition of water. The mixture was extracted with dichloromethane, concentrated, and column-sected with dichloromethane to obtain a red solid, which was the phenylthiophene-coordinated neutral iridium complex Ir6, 11.2 mg, with a yield of 28%. MALDI-TOF-MS ( m / z ): 802.3 ([M] + ).

[0040] Example 7: Synthesis of Ir7, a neutral iridium complex with phenylthiophene coordination The synthetic route for the neutral iridium complex Ir7, which contains phenylthiophene coordination, is as follows: Figure 7 As shown.

[0041] Synthesis of the phenylthiophene-coordinated neutral iridium complex Ir7: Intermediate 2d (43 mg, 0.05 mmol), dibenzoylmethane (16.8 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed in a dry two-necked flask. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under a nitrogen stream. The mixture was stirred and refluxed at 100 °C for 24 hours. After cooling to room temperature, the organic phase was concentrated, followed by the addition of water. The mixture was extracted with dichloromethane, concentrated, and column-sected with dichloromethane to obtain a red solid, which was the phenylthiophene-coordinated neutral iridium complex Ir7, 10.9 mg, with a yield of 26%. MALDI-TOF-MS ( m / z ):842.1 ([M] + ).

[0042] Example 8: Synthesis of Ir8, a neutral iridium complex with phenylthiophene coordination The synthetic route for the neutral iridium complex Ir8, which contains phenylthiophene coordination, is as follows: Figure 8 As shown.

[0043] Synthesis of the phenylthiophene-coordinated neutral iridium complex Ir8: Intermediate 2d (43 mg, 0.05 mmol), 2-phenylpyridine (16.6 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed in a dry two-necked flask. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under a nitrogen stream. The mixture was stirred and refluxed at 100 °C for 24 hours. After cooling to room temperature, the organic phase was concentrated, followed by the addition of water. The mixture was extracted with dichloromethane, concentrated, and column-sected with dichloromethane to obtain a red solid, which was the phenylthiophene-coordinated neutral iridium complex Ir8, 13.5 mg, in 35% yield. MALDI-TOF-MS ( m / z :773.5 ([M]) + ).

[0044] Example 9: Synthesis of Ir9, a neutral iridium complex with phenylthiophene coordination The synthetic route for the neutral iridium complex Ir9, which contains phenylthiophene coordination, is as follows: Figure 9 As shown.

[0045] 1. Synthetic intermediate 3d: In a dry Schlenk flask, intermediate 1c (0.06 g, 0.06 mmol), 4,4'-dimethoxy-2,2'-bipyridine (26 mg, 0.12 mmol), and silver trifluoromethanesulfonate (0.03 g, 0.13 mmol) were placed. The mixture was evacuated and purged with nitrogen three times. Then, 20 mL of dry dichloromethane was added under a nitrogen stream. The mixture was stirred at room temperature for 6 hours, filtered, and the filtrate was concentrated to 1 mL. A large amount of petroleum ether was then added to precipitate the solid. The solid was filtered and dried to obtain a yellow solid, which was intermediate 3d, yielding 84 mg (85% yield). MALDI-TOF-MS ( m / z ): 674.9 ([M-OTf] + ).

[0046] 2. Synthesis of Ir9, a neutral iridium complex coordinated with phenylthiophene: In a dry double-necked flask, intermediate 3d (41 mg, 0.05 mmol), acetylacetone (7.5 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under a nitrogen stream. The mixture was stirred and refluxed at 100°C for 24 hours. After cooling to room temperature, the organic phase was concentrated, followed by the addition of water. The mixture was extracted with dichloromethane, concentrated, and column-sected with dichloromethane to obtain a red solid, which was the neutral iridium complex Ir9 containing phenylthiophene coordination, 12.7 mg, with a yield of 38%. MALDI-TOF-MS ( m / z ): 665.7 ([M] + ).

[0047] Example 10: Synthesis of Ir10, a neutral iridium complex coordinated with phenylthiophene. The synthetic route for the neutral iridium complex Ir10 with phenylthiophene coordination is as follows: Figure 10 As shown.

[0048] Synthesis of the phenylthiophene-coordinated neutral iridium complex Ir10: Intermediate 3d (41 mg, 0.05 mmol), 2,2,6,6-tetramethyl-3,5-heptadecane (13.8 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed in a dry two-necked flask. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under a nitrogen stream. The mixture was stirred and refluxed at 100 °C for 24 hours. After cooling to room temperature, the organic phase was concentrated, followed by the addition of water. The mixture was extracted with dichloromethane, concentrated, and column-sected with dichloromethane to obtain a red solid, which was the phenylthiophene-coordinated neutral iridium complex Ir10, 13.5 mg, in 36% yield. MALDI-TOF-MS ( m / z ): 749.5 ([M] + ).

[0049] Example 11 Synthesis of Ir11, a neutral iridium complex with phenylthiophene coordination The synthetic route for the neutral iridium complex Ir11 with phenylthiophene coordination is as follows: Figure 11 As shown.

[0050] Synthesis of the phenylthiophene-coordinated neutral iridium complex Ir11: Intermediate 3d (41 mg, 0.05 mmol), benzoylmethane (16.8 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed in a dry two-necked flask. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under a nitrogen stream. The mixture was stirred and refluxed at 100 °C for 24 hours. After cooling to room temperature, the organic phase was concentrated, followed by the addition of water. The mixture was extracted with dichloromethane, concentrated, and column-sected with dichloromethane to obtain a red solid, which was the phenylthiophene-coordinated neutral iridium complex Ir11, 13.0 mg, in 33% yield. MALDI-TOF-MS ( m / z ): 789.9 ([M] + ).

[0051] Example 12 Synthesis of Ir12, a neutral iridium complex with phenylthiophene coordination The synthetic route for the neutral iridium complex Ir12 with phenylthiophene coordination is as follows: Figure 12 As shown.

[0052] Synthesis of the phenylthiophene-coordinated neutral iridium complex Ir12: Intermediate 3d (41 mg, 0.05 mmol), 2-phenylpyridine (16.6 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed in a dry two-necked flask. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under nitrogen flow. The mixture was stirred and refluxed at 100 °C for 24 hours. After cooling to room temperature, the organic phase was concentrated, followed by the addition of water. The mixture was extracted with dichloromethane, concentrated, and column-sected with dichloromethane to obtain a red solid, which was the phenylthiophene-coordinated neutral iridium complex Ir12, 15.1 mg, in 42% yield. MALDI-TOF-MS ( m / z ): 721.7 ([M+1] + ).

[0053] Example 13 Synthesis of Ir13, a neutral iridium complex with phenylthiophene coordination Synthetic route of Ir13, a neutral iridium complex with phenylthiophene coordination Figure 13 As shown.

[0054] 1. Synthetic intermediate 4d: Intermediate 1C (0.06 g, 0.06 mmol), 1,10-phenanthroline (22 mg, 0.12 mmol), and silver trifluoromethanesulfonate (0.03 g, 0.13 mmol) were placed in a dry Schlenk flask. The mixture was evacuated and purged with nitrogen three times. Then, 20 mL of dry dichloromethane was added under a nitrogen stream. The mixture was stirred at room temperature for 6 hours, filtered, and the filtrate was concentrated to 1 mL. A large amount of petroleum ether was added to precipitate the solid. The solid was filtered and dried to give a yellow solid intermediate 4D, 83 mg, with a yield of 88%. MALDI-TOF-MS ( m / z ): 638.8 ([M-OTf] + ).

[0055] 2. Synthesis of Ir13, a neutral iridium complex coordinated with phenylthiophene: In a dry double-necked flask, intermediate 4d (39 mg, 0.05 mmol), acetylacetone (7.5 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under a nitrogen stream. The mixture was stirred and refluxed at 100°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 concentrate was then purified by column chromatography with dichloromethane to obtain a red solid, which was the neutral iridium complex Ir13 containing phenylthiophene coordination, 12.6 mg, in 40% yield. MALDI-TOF-MS ( m / z ): 629.8 ([M] + ).

[0056] Single crystals of the neutral iridium complex Ir13, containing phenylthiophene coordination, were also obtained by slow diffusion of an ethanol solvent into its dichloromethane solution, and its structure is as follows. Figure 21 As shown.

[0057] Example 14 Synthesis of Ir14, a neutral iridium complex containing phenylthiophene coordination The synthetic route of the neutral iridium complex Ir14 containing phenylthiophene coordination is as follows: Figure 14 As shown.

[0058] Synthesis of the phenylthiophene-coordinated neutral iridium complex Ir14: Intermediate 4d (39 mg, 0.05 mmol), 2,2,6,6-tetramethyl-3,5-heptadecane (13.8 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed in a dry two-necked flask. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under a nitrogen stream. The mixture was stirred and refluxed at 100 °C for 24 hours. After cooling to room temperature, the organic phase was concentrated, followed by the addition of water. The mixture was extracted with dichloromethane, concentrated, and column-sected with dichloromethane to obtain a red solid, which was the phenylthiophene-coordinated neutral iridium complex Ir14, 13.5 mg, in 38% yield. MALDI-TOF-MS ( m / z ): 713.7 ([M] + ).

[0059] Example 15 Synthesis of Ir15, a neutral iridium complex containing phenylthiophene coordination The synthetic route for the neutral iridium complex Ir15 containing phenylthiophene coordination is as follows: Figure 15 As shown.

[0060] Synthesis of the phenylthiophene-coordinated neutral iridium complex Ir15: Intermediate 4d (39 mg, 0.05 mmol), benzoylmethane (16.8 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed in a dry two-necked flask. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under a nitrogen stream. The mixture was stirred and refluxed at 100 °C for 24 hours. After cooling to room temperature, the organic phase was concentrated, followed by the addition of water. The mixture was extracted with dichloromethane, concentrated, and column-sected with dichloromethane to obtain a red solid, which was the phenylthiophene-coordinated neutral iridium complex Ir15, 13.2 mg, in 35% yield. MALDI-TOF-MS ( m / z ): 753.9 ([M] + ).

[0061] Single crystals of the neutral iridium complex Ir15, containing phenylthiophene coordination, were also obtained by slow diffusion of an ethanol solvent into its dichloromethane solution, and its structure is as follows. Figure 22 As shown.

[0062] Example 16 Synthesis of Ir16, a neutral iridium complex containing phenylthiophene coordination The synthetic route of the neutral iridium complex Ir16 containing phenylthiophene coordination is as follows: Figure 16 As shown.

[0063] Synthesis of the phenylthiophene-coordinated neutral iridium complex Ir16: Intermediate 4d (39 mg, 0.05 mmol), 2-phenylpyridine (16.6 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed in a dry two-necked flask. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under a nitrogen stream. The mixture was stirred and refluxed at 100 °C for 24 hours. After cooling to room temperature, the organic phase was concentrated, followed by the addition of water. The mixture was extracted with dichloromethane, concentrated, and column-sected with dichloromethane to obtain a red solid, which was the phenylthiophene-coordinated neutral iridium complex Ir16, 15.4 mg, in 45% yield. MALDI-TOF-MS ( m / z ): 684.5 ([M] + ).

[0064] Example 17 Synthesis of Ir17, a neutral iridium complex with phenylthiophene coordination The synthetic route for the neutral iridium complex Ir17 with phenylthiophene coordination is as follows: Figure 17 As shown.

[0065] 1. Synthetic intermediate 5d: In a dry Schlenk flask, intermediate 1c (0.06 g, 0.06 mmol), 1,2-bis(diphenylphosphino)benzene (0.05 g, 0.12 mmol), and silver trifluoromethanesulfonate (0.03 g, 0.13 mmol) were placed. The mixture was evacuated and purged with nitrogen three times. Then, 20 mL of dry dichloromethane was added under a nitrogen stream. The mixture was stirred at room temperature for 6 hours, filtered, and the filtrate was concentrated to 1 mL. A large amount of petroleum ether was then added to precipitate the solid. The solid was filtered and dried to obtain a yellow solid, intermediate 5d, yielding 94 mg (75% yield). MALDI-TOF-MS ( m / z ): 905.1 ([M-OTf] + ).

[0066] 2. Synthesis of Ir17, a neutral iridium complex coordinated with phenylthiophene: In a dry double-necked flask, intermediate 5d (53 mg, 0.05 mmol), acetylacetone (7.5 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under a nitrogen stream. The mixture was stirred and refluxed at 100°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 concentrate was then purified by column chromatography with dichloromethane to obtain a red solid, which was the neutral iridium complex Ir17 containing phenylthiophene coordination, 11.6 mg, with a yield of 26%. MALDI-TOF-MS ( m / z ): 896.3 ([M] + ).

[0067] Example 18 Synthesis of Ir18, a neutral iridium complex with phenylthiophene coordination The synthetic route of the neutral iridium complex Ir18 containing phenylthiophene coordination is as follows: Figure 18 As shown.

[0068] Synthesis of the phenylthiophene-coordinated neutral iridium complex Ir18: Intermediate 5d (53 mg, 0.05 mmol), 2,2,6,6-tetramethyl-3,5-heptadecane (13.8 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed in a dry two-necked flask. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under nitrogen flow. The mixture was stirred and refluxed at 100 °C for 24 hours. After cooling to room temperature, the organic phase was concentrated, followed by the addition of water. The mixture was extracted with dichloromethane, concentrated, and column-sected with dichloromethane to obtain a red solid, which was the phenylthiophene-coordinated neutral iridium complex Ir18, 13.2 mg, in 27% yield. MALDI-TOF-MS ( m / z ): 980.3 ([M] + ).

[0069] Example 19 Synthesis of Ir19, a neutral iridium complex with phenylthiophene coordination The synthetic route for the neutral iridium complex Ir19, which contains phenylthiophene coordination, is as follows: Figure 19 As shown.

[0070] Synthesis of the phenylthiophene-coordinated neutral iridium complex Ir19: Intermediate 5d (53 mg, 0.05 mmol), benzoylmethane (16.8 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed in a dry two-necked flask. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under a nitrogen stream. The mixture was stirred and refluxed at 100 °C for 24 hours. After cooling to room temperature, the organic phase was concentrated, followed by the addition of water. The mixture was extracted with dichloromethane, concentrated, and column-sected with dichloromethane to obtain a red solid, which was the phenylthiophene-coordinated neutral iridium complex Ir19, 12.7 mg, in 25% yield. MALDI-TOF-MS ( m / z ): 1020.4 ([M] + ).

[0071] Example 20 Synthesis of Ir20, a neutral iridium complex coordinated with phenylthiophene The synthetic route for the neutral iridium complex Ir20 with phenylthiophene coordination is as follows: Figure 20 As shown.

[0072] Synthesis of the phenylthiophene-coordinated neutral iridium complex Ir20: Intermediate 5d (53 mg, 0.05 mmol), 2-phenylpyridine (16.6 mg, 0.075 mmol), and Na2CO3 (79.5 mg, 0.075 mmol) were placed in a dry two-necked flask. The mixture was evacuated and purged with nitrogen three times. Then, 10 mL of ethylene glycol monoethyl ether was added under nitrogen flow. The mixture was stirred and refluxed at 100 °C for 24 hours. After cooling to room temperature, the organic phase was concentrated, followed by water addition and extraction with dichloromethane. The concentrate was then purified by column chromatography with dichloromethane to obtain a red solid, which was the phenylthiophene-coordinated neutral iridium complex Ir20, 14.3 mg, in 30% yield. MALDI-TOF-MS ( m / z ): 951.3 ([M] + ).

[0073] Example 21 Fabrication and Characterization of OLED Devices The fabrication steps for an OLED device with ITO / PEDOT:PSS (50nm) / Ir1~Ir20 (1wt%): mCP and m-MTDATA (40nm) / DPEPO (10nm) / TmPyPB (50nm) / Liq (1nm) / Al (100nm) are as follows: (i) Use a 5% Decon90 cleaning solution to sonicate for 30 minutes, then sonicate several times with deionized water, then sonicate with isopropanol, and dry with nitrogen; treat under oxygen plasma for 5 minutes to clean the ITO surface and improve the work function of the ITO electrode. (ii) A PEDOT:PSS solution was spin-coated onto an ITO glass substrate treated with oxygen plasma to obtain a 50 nm thin film. After spin-coating, 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. PEDOT is a polymer of 3,4-ethylenedioxythiophene monomer, and PSS is polystyrene sulfonate.

[0074] (iii) First, mCP, m-MTDATA, and complexes (Ir1~Ir20) are dissolved in toluene at a certain mass ratio (49:49:2). Complexes Ir1~Ir20 are incorporated as guest materials into the mixed host materials mCP and m-MTDATA at a weight ratio of 2 wt%. This solution is then spin-coated in a nitrogen glove box to obtain a 40 nm film, followed by annealing at 120 °C for 10 minutes. mCP is an abbreviation for 1,3-dicarbazol-9-ylbenzene, and m-MTDATA is an abbreviation for 4,4',4''-tris(N-3-methylphenyl-N-phenylamino)triphenylamine.

[0075] (iv) The spin-coated device was placed in a vacuum evaporation chamber, and 10 nm of DPEPO, 50 nm of TmPyPB, 1 nm of Liq, and 100 nm of aluminum were deposited sequentially to obtain an OLED light-emitting device. DPEPO is an abbreviation for di[2-((oxo)diphenylphosphine)phenyl] ether, TmPyPB is an abbreviation for 1,3,5-tris(3-pyridyl-3-phenyl)benzene, and Liq is an abbreviation for lithium 8-hydroxyquinoline. The current-voltage-luminance (JVL) characteristics of this OLED device were characterized using characterization equipment, and important parameters such as efficiency and external quantum efficiency were recorded. The maximum external quantum efficiency (EQE) of the OLED was measured to be 20.3%. Details are shown in Table 1.

[0076] Table 1. Maximum external quantum efficiency of OLED devices fabricated from Ir1 to Ir20

[0077] Further optimizations, such as optimization of device structure, and optimization of the combination of hole transport materials (HTM), electron transport materials (ETM) and host materials, will further improve device performance, especially efficiency, driving voltage and lifetime.

Claims

1. A neutral iridium complex containing phenylthiophene coordination, the structural formula of which is shown in (I): ,in, It is a bidentate monoanion ligand. It is a bidentate neutral ligand.

2. The neutral iridium complex containing phenylthiophene coordination according to claim 1, characterized in that, in, It can be selected from any one of the following general formulas L1 to L15, wherein R3 to R72 are selected from -H, -F, -Cl, Br, I, -D, -CN, -NO2, -CF3, B(OR2)2, Si(R2)3, straight-chain alkanes, alkane ethers, alkane thioethers containing 1 to 10 carbon atoms, branched alkanes, cycloalkanes, alkane ethers or alkane thioethers containing 3 to 10 carbon atoms, hydrogen groups or aryl groups containing 6 to 10 carbon atoms, wherein the dashed line represents the bond directly connected to the metal element iridium; 3. The neutral iridium complex containing phenylthiophene coordination according to claim 1, characterized in that, in, The formula can be any one of the following general formulas N1 to N8: Wherein, R1 is selected from -H, -F, -Cl, -Br, -I, -D, -CN, -NO2, -CF3, -OCH3, tert-butyl, substituted or unsubstituted carbazole, substituted or unsubstituted diphenylamino, the dashed line represents the bond directly connected to the metal element iridium, x is any integer from 0 to 2, y is any integer from 0 to 4, z is any integer from 0 to 3, and u is any integer from 0 to 5.

4. The neutral iridium complex containing phenylthiophene coordination according to claim 1, characterized in that, Its general formula is shown in the following structure: Among them, R is a bidentate monoanion ligand, and R is selected from one or more of hydrogen, tert-butyl or methoxy.

5. The neutral iridium complex containing phenylthiophene coordination according to claim 1, characterized in that, The neutral iridium complex is selected from the following complexes Ir1-Ir20: 。 6. The method for preparing the neutral iridium complex containing phenylthiophene coordination according to any one of claims 1 to 5, characterized in that, Includes the following steps: 1) First, using 3,4-dibromothiophene as a raw material, intermediate 1a is formed by a Suzuki coupling reaction with 2-bromophenylboronic acid. Then, it is subjected to a low temperature of -78°C. o Under C environment, bromine is desorbed by n-butyllithium, and then intermediate 1b is formed under the action of copper chloride; 2) Then, using 1,5-cyclooctadiene iridium chloride dimer and intermediate 1b prepared in step 1) as raw materials, under anhydrous and oxygen-free conditions, the coordination of the dianionic ligand phenylthiophene with metallic iridium is achieved by oxidative addition reaction, finally forming the first-step precursor 1c; then, under the action of silver trifluoromethanesulfonate, the chlorine atom is removed, and then it reacts with neutral ligands (2,2'-bipyridine, 4,4'-di-tert-butyl-2,2-bipyridine, 4,4'-dimethoxy-2,2'-bipyridine, 1,10-phenanthroline, 1,2-bis(diphenylphosphine)benzene) under mild conditions to obtain the second-step complex precursors; 3) Finally, the complex precursor prepared in step 2) can be reacted with monoanionic ligands (acetylacetone, 2,2,6,6-tetramethyl-3,5-heptadecylone, dibenzoylmethane, 2-phenylpyridine) under a high temperature and alkaline environment to obtain the corresponding neutral iridium complexes.

7. The use of the neutral iridium complex containing phenylthiophene coordination according to any one of claims 1 to 5 in the preparation of organic electronic devices.

8. The application according to claim 7, characterized in that, The organic electronic device is one or more of the following: organic light-emitting diode, organic photovoltaic cell, organic light-emitting cell, organic field-effect transistor, organic laser, organic spintronic device, organic sensor, and organic plasmon emitter diode.

9. The application according to claim 7, characterized in that, The mass concentration of the neutral iridium complex containing phenylthiophene coordination in the matrix is ​​1~10 wt%.

10. An organic electronic device, characterized in that, The organic electronic device comprises the phenylthiophene-coordinated neutral iridium complex as described in any one of claims 1 to 5, wherein, preferably, the phenylthiophene-coordinated neutral iridium complex has a mass concentration of 1 to 10 wt%.

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