Phosphorescent iridium complex, luminescent material and organic electroluminescent device

Abstract

The present invention relates to the field of organic electroluminescence technology, and discloses a phosphorescent iridium complex, a luminescent material and an organic electroluminescent device. Among them, the phosphorescent iridium complex is a complex having the structure of general formula (1): Ir(L A )2(L B ) (1), where the L A is the first ligand, which has the structure of general formula (2): #imgabs0# (2), and the L B is the second ligand, and its structural formula is as formula (L B 1) or as (L B 2): #imgabs1# (L B 1); #imgabs2# (L B 2). The organic electroluminescent device prepared by using the phosphorescent iridium complex has high color purity and external quantum conversion efficiency.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescence technology, and particularly to a phosphorescent iridium complex, a luminescent material, and an organic electroluminescent device. Background Technology

[0002] Luminescent materials are the core of OLEDs. Compared to traditional fluorescent luminescent materials, phosphorescent iridium complexes with heavy metal centers (such as ruthenium, rhodium, iridium, and platinum) can simultaneously acquire singlet and triplet excitons due to their strong spin-orbit coupling, theoretically achieving a quantum efficiency of 100%. Among all phosphorescent materials, complexes are the most promising organic electroluminescent materials: iridium has a large atomic number and a strong spin-orbit coupling effect, greatly improving the phosphorescence emission performance of complexes; neutral complexes formed by trivalent iridium ions and ligands have good thermal stability and film-forming properties, which is beneficial for fabricating OLED devices; in addition, complexes also have advantages such as short excited-state lifetime, high luminous efficiency, and easily adjustable emission color.

[0003] The phosphorescence emission characteristics of the complexes are mainly due to the combined effects of two mechanisms: singlet and triplet metal-to-ligand charge transfer (1MLCT, 3MLCT) and triplet ligand-centered charge transfer (3LC) states, with a small component of triplet ligand-to-ligand (3LLCT) emission. Generally, the MLCT emission states of complexes do not exhibit vibrational fine structure and have a wide spectral range but poor color purity. Complexes dominated by 3LC emission show more obvious vibrational fine structure, but the multiple vibrational modes of the ligands and complexes result in more shoulder peaks, a similarly wide spectral range, and less than ideal color purity. The wide emission spectrum limits the ability of the complexes to meet the display requirements of high color purity red / green / blue and is also unfavorable for the fabrication of high-performance commercial OLED devices.

[0004] In commercial OLED applications, while narrow electroluminescence spectra can be achieved by adding filters or optical microcavities, the introduction of additional processes significantly increases the cost of OLED fabrication and introduces additional energy losses. Therefore, developing efficient narrow-spectrum emission complexes, especially high-color-purity complexes that meet the CIE coordinate requirements of commercial applications, is of great significance for fabricating high-performance, high-color-purity OLED devices.

[0005] Indolecarbazole (ICz) structures possess excellent planar rigidity and hole transport capabilities. Iridium (III) complexes based on ICz structures have also been proven to be high-performance OLED emitters, as illustrated in patent applications CN114644658A, CN114989222A, and EP3960747A1. However, while the introduction of ICz structures improves the stability of these complexes, the spectra are not narrowed, and color purity is relatively poor, with reported full width at half maximum (FWHM) values ​​all above 60 nm. In CN114716483A, the reported complexes primarily rely on the rigid structure of the host ligand itself to achieve some spectral narrowing, but the significant shoulder peak intensity still negatively impacts color purity, and further suppression of this intensity is relatively difficult. Furthermore, the short axial length of these molecules results in limited horizontal orientation in the deposited thin film, weakening the light extraction effect and hindering the development of higher-performance OLED devices.

[0006] It is evident that existing technologies still need improvement and enhancement. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the purpose of this invention is to provide a phosphorescent iridium complex, a luminescent material, and an organic electroluminescent device, with the aim of improving the luminous efficiency and color purity of the organic electroluminescent device.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] The first aspect of this invention provides a phosphorescent iridium complex having a structure of general formula (1):

[0010] Ir(L A )2(L B (1),

[0011] Wherein, the L A As the first ligand, it has the structure of general formula (2):

[0012] (2),

[0013] The L B It is the second ligand, and its structural formula is as shown in formula (L). B 1) or as in (L) B 2):

[0014] (L) B 1); (L) B 2).

[0015] A second aspect of the present invention also provides a luminescent material comprising a host material and a guest material, wherein the guest material is a phosphorescent iridium complex as described above.

[0016] A third aspect of the present invention also provides an organic electroluminescent device, comprising one or more light-emitting functional layers, wherein at least one light-emitting functional layer is prepared from the light-emitting material as described above.

[0017] Beneficial effects:

[0018] The phosphorescent iridium complex, luminescent material, and organic electroluminescent device provided by this invention have the following advantages compared to the prior art:

[0019] (1) The phosphorescent iridium complex is coordinated with two large first ligands and one second ligand to form an octahedral spatial structure, which greatly suppresses the stacking effect between molecules and effectively reduces the problem of spectral broadening and efficiency decay of the complex based on concentration.

[0020] (2) By introducing steric groups at specific positions of the first ligand, the octahedral spatial structure of the complex is utilized to generate a significant steric effect between the two first ligands, forming an interlocking structure within the molecule, suppressing the high-frequency and low-frequency vibrations of the ligands themselves, reducing the configurational difference between the ground state and the excited state, and lowering the recombination energy, thereby achieving further narrowing of the spectrum of the complex.

[0021] (3) The substituents on the pyridine ring in the first ligand are located in the long axis direction of the complex, which is consistent with the direction of the triplet transition dipole moment of this type of complex. This is beneficial to improve the horizontal orientation of the complex in the vapor-deposited thin film, thereby improving the light extraction efficiency of the electroluminescent device and exhibiting higher external quantum efficiency.

[0022] (4) Due to the electron-donating ability of structures such as carbazole, furan and thiophene ring, the ligands have bipolar transport characteristics, which effectively improves the transport ability of holes and electrons in electroluminescent devices, resulting in organic electroluminescent devices with high efficiency and high color purity. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the organic electroluminescent device provided by the present invention.

[0024] Figure 2 This is the emission spectrum of Example 9.

[0025] Figure 3 The results show the molecular-level orientation test results for ref-3 (left) and Example 4 (right).

[0026] Figure 4Comparison of electroluminescence spectra of Examples 9, ref-1, ref-4, and ref-5.

[0027] In the attached diagram, the following labels are used: 1-substrate, 2-hole injection layer, 3-hole transport layer, 4-light emission layer, 5-electron transport layer, 6-electron injection layer, 7-metal cathode. Detailed Implementation

[0028] This invention provides a phosphorescent iridium complex, a luminescent material, and an organic electroluminescent device. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the following embodiments are provided to further illustrate the invention in detail. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0029] This invention provides a phosphorescent iridium complex having a general formula (1):

[0030] Ir(L A )2(L B (1),

[0031] This complex has three ligands, which are arranged in a mutually perpendicular spatial relationship, forming an octahedral spatial structure. Furthermore, the steric hindrance between the ligands creates an interlocking structure within the molecule, increasing the rigidity of the complex itself. This, in turn, suppresses the high-frequency oscillations of the ligands, reduces the configurational difference between the ground and excited states, and decreases the recombination energy. Consequently, it achieves a narrower phosphorescence emission spectrum and a weaker vibrational shoulder, thereby improving the color purity of the complex.

[0032] In general formula (1), the L A As the first ligand, it has the structure of general formula (2):

[0033] (2),

[0034] The ligand L of the general formula (2) A It has a planar structure and a large volume; therefore, the two L-shaped structures... A During the formation of the octahedral structure of the complex, ligands exhibit steric hindrance among themselves, thereby enhancing the rigidity of the complex structure, especially ligand L. A The planar structure imparts significant rigidity to the bonding benzene ring structure, restricting the planar vibrations of the ligand mechanism and thus suppressing high-frequency vibrations in the complex; furthermore, based on the repulsive effect between charges, the two ligands L A A significant van der Waals force is generated between them, resulting in a certain degree of repulsion. Under this mutual repulsion, the ligand L... APerpendicular oscillations are also restricted, further enhancing the rigidity of the ligand and suppressing high-frequency vibrations of the complex. Furthermore, ligand L... A It can form large conjugated systems, especially those containing five-membered heterocyclic structures, which can further enhance the electron-donating ability of ligands, increase the highest occupied orbital energy level of ligands, and improve the emission composition of LC state.

[0035] The L B It is the second ligand, which has the following properties (L B 1) or as in (L) B 2) Structure:

[0036] (L) B 1); (L) B 2).

[0037] The L B 1 Structure and L B The ligand with the 2-structure also has a large volume, and it is effective for two L... A The steric hindrance between them has a complementary effect, which can further enhance the rigidity of the complex.

[0038] Therefore, in this embodiment, through two ligands L A and a ligand L B The mutual restriction between ligands enables mutual locking between ligands and enhances the emission component of the LC state. This has a significant inhibitory effect on the coupling of vibrational-electronic energy levels in the complex, resulting in a narrower phosphorescent emission spectrum with a spectral half-width of 20–40 nm and a relatively small vibrational shoulder intensity, which greatly improves the color purity of the complex.

[0039] In a preferred embodiment, in formula (2), A and B are each independently a monocyclic or polycyclic structure containing a five- or six-membered carbon ring or a heterocyclic ring, or a structure without rings.

[0040] X is one of O, S, Se, NR6, or C(R7) (R8), which can form pyrrole rings, furan rings, thiophene rings, etc., which can further enhance the electron-donating ability of the ligand, thereby increasing the highest occupied orbital energy level of the ligand and improving the emission composition of the LC state.

[0041] R1 and R2 are two groups attached to the same benzene ring. Depending on the substituents of R1 and R2, the lengths of the two L groups will be shortened to varying degrees. A The distance between ligands can increase the steric hindrance effect between them. However, when choosing substituents, attention must be paid to the volume of the two groups. If the volume is too large, it will make bonding difficult in the complex, while if the volume is too small, the mutual restraint effect will be weakened.

[0042] In a preferred embodiment, R1 is one of hydrogen atom, deuterium atom, fluorine atom, halogen atom, or alkyl group having 1 to 4 carbon atoms, and has a certain steric hindrance effect;

[0043] The influence of ring B on R2 can be one of the following: when ring B is absent, R2 is selected from fluorine atom, halogen atom, cyano, nitro-substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, substituted or unsubstituted fluoroalkyl group with 1 to 20 carbon atoms, substituted or unsubstituted haloalkyl group with 1 to 20 carbon atoms, and substituted or unsubstituted alkoxy group with 1 to 20 carbon atoms; when ring B is present, R2 is selected from hydrogen atom, deuterium atom, fluorine atom, halogen atom, cyano, nitro-substituted or unsubstituted alkyl group with 1 to 10 carbon atoms, substituted or unsubstituted fluoroalkyl group with 1 to 10 carbon atoms, substituted or unsubstituted haloalkyl group with 1 to 10 carbon atoms, and substituted or unsubstituted alkoxy group with 1 to 10 carbon atoms.

[0044] R5 is a substituent attached to the pyridine ring. The number of R5 is one or the maximum allowed number of substitutions on the pyridine ring. It can be the same as or different from R3 and R4. R3, R4, and R5 are each independently selected from one of the following: hydrogen atom, deuterium atom, fluorine atom, halogen atom, cyano group, substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, substituted or unsubstituted alkenyl group with 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl group with 3 to 20 carbon atoms, substituted or unsubstituted amino group with 1 to 20 carbon atoms, substituted or unsubstituted silyl group with 1 to 20 carbon atoms, substituted or unsubstituted alkoxy group with 1 to 20 carbon atoms, substituted or unsubstituted fluoroalkyl group with 1 to 20 carbon atoms, substituted or unsubstituted aryloxy group with 6 to 50 carbon atoms, substituted or unsubstituted alkylthio group with 1 to 20 carbon atoms, substituted or unsubstituted aryl group with 6 to 50 carbon atoms, and substituted or unsubstituted heteroaryl group with 5 to 50 carbon atoms.

[0045] In a preferred embodiment, the substitution site of R5 is preferably located in the direction of the extension line of the Ir-N bond of the coordination bond, which is consistent with the direction of the triplet transition dipole moment of the complex. This facilitates the horizontal dipole orientation of the complex molecule in the light-emitting device, thereby significantly improving the light extraction efficiency of the device and the final external quantum efficiency of the device.

[0046] R6 to R8 are substituents attached to X in formula (2), each independently selected from one of the following: hydrogen atom, deuterium atom, fluorine atom, substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, substituted or unsubstituted alkenyl group with 1 to 20 carbon atoms, substituted or unsubstituted alkynyl group with 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl group with 3 to 20 carbon atoms, substituted or unsubstituted amino group with 1 to 20 carbon atoms, substituted or unsubstituted silyl group with 1 to 20 carbon atoms, substituted or unsubstituted alkoxy group with 1 to 20 carbon atoms, substituted or unsubstituted fluoroalkyl group with 1 to 20 carbon atoms, substituted or unsubstituted aryl group with 6 to 50 carbon atoms, substituted or unsubstituted alkylthio group with 1 to 20 carbon atoms, substituted or unsubstituted aryl group with 6 to 50 carbon atoms, and substituted or unsubstituted heteroaryl group with 5 to 50 carbon atoms.

[0047] In a preferred embodiment, the L A Independently selected from any of the following structural formulas:

[0048] , , , , , , ;

[0049] In formula L A 1~L A In formula 7, Y is one of O, S, and Se. A 1~L A 7-structure ligand L A This allows the complex to form an octahedral structure, and due to the strong repulsive effect between the ligands, the complex can have stronger rigidity and reduce the appearance of shoulder peaks.

[0050] To facilitate understanding of the spatial coordination structure of coordination compounds and the repulsive interactions between ligands, L A Taking 5 as an example, equation (1) can also be written as shown in equation (3). It should be noted that other L A Complexes formed by ligand combinations can also be written in this form:

[0051] (3);

[0052] In equation (3), due to the octahedral structure of the complex, the mutual locking effect of the ligands mainly originates from the two first ligands, with the locking effect from the second ligand being secondary. However, when the introduced second ligand is large, it will restrict the coordination of the complex's own pyridine ring, resulting in the inability to form the target complex structure. Therefore, complexes containing three identical ligands proposed in this invention (homogamous complexes) are relatively difficult or impossible to obtain, and their expected effects cannot be similar to those of the complexes proposed in this invention.

[0053] In a preferred embodiment, in the L B 1 Structure and L B In the ligands of structure 2, R9~R 12 Each of the following is independently selected from hydrogen atom, deuterium atom, fluorine atom, halogen atom, cyano group, substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, substituted or unsubstituted alkenyl group with 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl group with 3 to 20 carbon atoms, substituted or unsubstituted amino group with 2 to 20 carbon atoms, substituted or unsubstituted silyl group with 3 to 20 carbon atoms, substituted or unsubstituted alkoxy group with 1 to 20 carbon atoms, substituted or unsubstituted fluoroalkyl group with 1 to 20 carbon atoms, substituted or unsubstituted aryloxy group with 6 to 20 carbon atoms, substituted or unsubstituted alkylthio group with 1 to 20 carbon atoms, substituted or unsubstituted aryl group with 6 to 20 carbon atoms, and substituted or unsubstituted heteroaryl group with 5 to 20 carbon atoms.

[0054] In a preferred embodiment, the complex is selected from any of the following chemical structural formulas:

[0055] , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , .

[0056] These complexes exhibit narrow phosphorescence emission spectra with a full width at half maximum (FWHM) of 20-40 nm and low vibrational shoulder intensity, resulting in high color purity. Therefore, these complexes possess superior molecular orientation and bipolar transport properties in electroluminescent devices, leading to higher performance and color purity in the fabricated OLED devices.

[0057] The aforementioned phosphorescent iridium complexes are commercially available or prepared using organic synthesis methods. The following discussion focuses on the first ligand, L... A For L A A representative preparation method for the phosphorescent iridium complex with 5 structural formulas is illustrated by way of example, but is not limited to the example method; other synthetic methods not mentioned in this invention may also be used. The specific synthetic route is as follows:

[0058] ligand L A General synthesis method of 5

[0059] The synthesis of the complex requires the completion of the first ligand L. A Synthesis of the first ligand L. A Its structure has modular characteristics, therefore its synthesis method is as follows:

[0060] .

[0061] The specific synthesis steps are as follows:

[0062] Under a nitrogen atmosphere, 1 part of starting material (A), 1.2 parts of starting material (B), 0.05 parts of tris(dibenzylacetone)palladium, 0.1 parts of 1,1'-bis(diphenylphosphine)ferrocene, and 3 parts of sodium tert-butoxide were dissolved in an appropriate amount of toluene solvent. The mixture was heated and stirred at 100°C for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered with diatomaceous earth, and washed with ethyl acetate. The organic phase was then separated by liquid chromatography, washed three times with saturated brine, dried over anhydrous magnesium sulfate, and the solvent was removed by rotary evaporation using silica gel adsorption. The product was then purified by silica gel column chromatography to obtain a white or pale yellow solid product. 1 part of the obtained product, 0.05 parts of palladium acetate, 0.1 parts of tri-tert-butylphosphine, and 3 parts of cesium carbonate were dispersed in an appropriate amount of N,N'-dimethylacetamide and heated to 140°C under a nitrogen atmosphere for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was stirred for 0.5 hours. The precipitate was then directly filtered off. The precipitate was separated by a simple silica gel short column to obtain a white or pale yellow solid intermediate (C).

[0063] Under a nitrogen atmosphere, 1 part of intermediate (C), 1.2 parts of starting material (D), and 1.2 parts of cesium carbonate were dispersed in a certain amount of N,N-dimethylformamide and stirred at 120°C for 12 hours. After the reaction was complete, the mixture was cooled to room temperature, a large amount of water was added, and stirring was continued for 1 hour. The mixture was then filtered. The filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid intermediate (E).

[0064] Under a nitrogen atmosphere, a mixture of 1 part intermediate (E), 0.1 part palladium acetate, 0.2 part tri-tert-butylphosphine, and 2 parts cesium carbonate was dispersed in a certain amount of N,N'-dimethylacetamide and stirred at 140°C for 12 hours. After the reaction was completed, a large amount of water was added, and the filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid intermediate (F).

[0065] One part of intermediate (F) and 1.2 parts of N-bromosuccinimide were dispersed in a certain amount of dichloromethane and stirred at room temperature for 6 hours. After the reaction was completed, the solvent was concentrated, and a large amount of methanol was added. The mixture was then filtered to collect a large amount of white precipitate. After washing three times with methanol, a white intermediate (G) was collected.

[0066] Under a nitrogen atmosphere, 1 part of intermediate (G), 1.1 parts of pinacol diborate, 0.05 parts of 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride, and 4 parts of potassium acetate were dispersed in a certain amount of dioxane and stirred at 110°C for 12 hours. After the starting materials reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was purified by silica gel column chromatography to obtain a white solid intermediate (H).

[0067] Under a nitrogen atmosphere, 1 part of intermediate (H), 1.2 parts of pyridine derivative (I), 0.05 parts of tetraphenylphosphine palladium, and 1.5 parts of potassium carbonate were dispersed in a mixed solvent of tetrahydrofuran and water (tetrahydrofuran / water = 3:1). The mixture was stirred at 75°C for 12 hours. After the reactants had reacted completely, the mixture was cooled to room temperature, quenched with water, and extracted three times with dichloromethane and water. The combined organic phases were concentrated and passed through a column chromatography column. The crude product was further purified by column chromatography to obtain a white ligand (J), which has the structural formula L. A The first ligand of 5.

[0068] Synthesis of coordination compounds

[0069] Obtaining ligand L A After step 5, the corresponding complexes are synthesized. The specific synthesis method is as follows:

[0070] ;

[0071] 2.1 parts of ligand (J) and 1 part of iridium trichloride were dispersed in a certain amount of ethylene glycol ethyl ether / water mixed solvent of 3:1. After purging with nitrogen three times, the mixture was stirred at 110 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, the mixture was filtered, the filter cake was collected, washed twice with petroleum ether, and dried to obtain a yellow to brown solid intermediate (K).

[0072] Add 1 part of intermediate (K) and 1.2 parts of auxiliary ligand or ligand L. BFive parts of potassium carbonate were dispersed in a certain amount of ethylene glycol ethyl ether. After purging with nitrogen three times, the mixture was stirred at 140 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, the mixture was filtered, the filter cake was collected, and then purified by column chromatography. A yellow to orange-red complex (L) was obtained.

[0073] This preparation method can basically prepare structures with the L-shaped structure. A 5 as the first ligand L A Phosphorescent iridium complexes.

[0074] The following are the specific synthesis schemes for Ir-1, Ir-7, Ir-14, Ir-16, Ir-29, Ir-33, Ir-43, Ir-55, and Ir-66:

[0075] 1) Synthesis method of Ir-1:

[0076] ;

[0077] Under a nitrogen atmosphere, 1 part 2-chloro-4-(2,6-dimethylphenyl)pyridine, 1.2 parts (4-fluoro-2-methylphenyl)boric acid, 0.05 parts tetraphenylphosphine palladium, and 1.5 parts potassium carbonate were dispersed in a certain amount of a mixed solvent of tetrahydrofuran / water = 3:1, and stirred at 75 degrees Celsius for 12 hours. After the reactants had reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was further purified by column chromatography to obtain a white ligand (1).

[0078] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 292.3132 [M+H] +

[0079] ;

[0080] Under a nitrogen atmosphere, 1 part of intermediate (1), 1.2 parts of 3-bromo-2-naphthol, and 1.2 parts of cesium carbonate were dispersed in a certain amount of N,N-dimethylformamide and stirred at 120 degrees Celsius for 12 hours. After the reaction was complete, the mixture was cooled to room temperature, a large amount of water was added, and stirring was continued for 1 hour. The mixture was then filtered. The filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid product (2).

[0081] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 495.3232 [M+H] +

[0082] ;

[0083] Under a nitrogen atmosphere, a mixture of 1 part intermediate (2), 0.1 part palladium acetate, 0.2 part tri-tert-butylphosphine, and 2 parts cesium carbonate was dispersed in a certain amount of N,N'-dimethylacetamide and stirred at 140 degrees Celsius for 12 hours. After the reaction was completed, a large amount of water was added, and the filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid (3).

[0084] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 413.3638 [M+H] +

[0085] ;

[0086] 2.1 parts of ligand (3) and 1 part of iridium trichloride were dispersed in a certain amount of ethylene glycol ethyl ether / water = 3:1 mixed solvent. After purging with nitrogen three times, the mixture was stirred at 110 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, the mixture was filtered, the filter cake was collected, washed twice with petroleum ether, and dried to obtain a yellow solid product (4).

[0087] ;

[0088] One part of intermediate (4), 1.2 parts of 2,2,6,6-tetramethylheptane-3,5-dione, and 5 parts of potassium carbonate were dispersed in a certain amount of ethylene glycol diethyl ether. After purging with nitrogen three times, the mixture was stirred at 140 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was filtered. The filter cake was collected and then purified by column chromatography. The yellow iridium complex Ir-1 was obtained.

[0089] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 1201.4430 [M+H] +

[0090] 1H NMR (500 MHz, CDCl3) δ 9.20 (d, J = 1.6 Hz, 2H), 8.94 (d, J = 1.6Hz, 2H), 8.35 (dt, J = 7.6, 1.4 Hz, 2H), 7.62 (dt, J = 7.8, 1.4 Hz, 2H), 7.75- 7.58 (m, 2H), 7.57 – 7.45 (m, 6H), 7.33 (d, J = 7.6 Hz, 4H), 6.93 (dd, J =20.9, 1.4 Hz, 4H), 5.00 (s, 1H), 2.58 (s, 18H), 0.94 (s, 9H), 0.74 (s, 9H).

[0091] 2) Synthesis method of Ir-7:

[0092] ;

[0093] Under a nitrogen atmosphere, 4-tert-butylaniline, 1.2 parts of 2-bromo-5-methyliodobenzene, 0.05 parts of tris(dibenzylacetone)palladium, 0.1 parts of 1,1'-bis(diphenylphosphine)ferrocene, and 3 parts of sodium tert-butoxide were dissolved in an appropriate amount of toluene solvent, and the mixture was heated and stirred at 100°C for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered with diatomaceous earth, and washed with ethyl acetate. The organic phase was then separated by liquid chromatography, washed three times with saturated brine, dried over anhydrous magnesium sulfate, and the solvent was removed by rotary evaporation with silica gel adsorption. The product was then purified by silica gel column chromatography to obtain a pale yellow solid product (5).

[0094] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 319.2566 [M+H] +

[0095] ;

[0096] Under a nitrogen atmosphere, a mixture of 1 part intermediate (5), 0.1 part palladium acetate, 0.2 part tri-tert-butylphosphine, and 2 parts cesium carbonate was dispersed in a certain amount of N,N'-dimethylacetamide and stirred at 140 degrees Celsius for 12 hours. After the reaction was completed, a large amount of water was added, and the filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid (6).

[0097] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 238.3455 [M+H] +

[0098] ;

[0099] Under a nitrogen atmosphere, 1 part of intermediate (6), 1.2 parts of 3-fluorothiophene, and 1.2 parts of cesium carbonate were dispersed in a certain amount of N,N-dimethylformamide and stirred at 120 degrees Celsius for 12 hours. After the reaction was complete, the mixture was cooled to room temperature, a large amount of water was added, and stirring was continued for 1 hour. The mixture was then filtered. The filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid product (7).

[0100] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 319.1300 [M+H] +

[0101] ;

[0102] One part of intermediate (7) and 1.2 parts of N-bromosuccinimide were dispersed in a certain amount of dichloromethane and stirred at room temperature for 6 hours. After the reaction was completed, the solvent was concentrated, and a large amount of methanol was added. A large amount of white precipitate was collected by filtration. After washing with methanol three times, a white product (8) was collected.

[0103] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 397.1825 [M+H] +

[0104] ;

[0105] Under a nitrogen atmosphere, 1 part of intermediate (8), 1.1 parts of pinacol diborate, 0.05 parts of 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride, and 4 parts of potassium acetate were dispersed in a certain amount of dioxane and stirred at 110 degrees Celsius for 12 hours. After the reactants had reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was purified by silica gel column chromatography to obtain a white solid product (9).

[0106] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 445.2625 [M+H] +

[0107] ;

[0108] Under a nitrogen atmosphere, 1 part of intermediate (9), 1.2 parts of 2-bromo-4-(2,6-dimethylphenyl)pyridine, 0.05 parts of tetraphenylphosphine palladium, and 1.5 parts of potassium carbonate were dispersed in a certain amount of tetrahydrofuran / water = 3:1 mixed solvent and stirred at 75 degrees Celsius for 12 hours. After the starting materials reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was further purified by column chromatography to obtain a white ligand (10).

[0109] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 501.6932 [M+H] +

[0110] ;

[0111] 2.1 parts of ligand (10) and 1 part of iridium trichloride were dispersed in a certain amount of ethylene glycol ethyl ether / water = 3:1 mixed solvent. After purging with nitrogen three times, the mixture was stirred at 110 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, the mixture was filtered, the filter cake was collected, washed twice with petroleum ether, and dried to obtain a yellow solid product (11).

[0112] ;

[0113] One part of intermediate (11), 1.2 parts of 3,7-diethylnonane-4,6-dione, and 5 parts of potassium carbonate were dispersed in a certain amount of ethylene glycol diethyl ether. After purging with nitrogen three times, the mixture was stirred at 140°C for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was filtered. The filter cake was collected and then purified by column chromatography. The orange-red iridium complex Ir-7 was obtained.

[0114] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 1403.5840 [M+H] +

[0115] 1H NMR (500 MHz, CDCl3) δ 9.16 (d, J = 1.4 Hz, 2H), 8.84 (d, J = 1.6Hz, 2H), 8.36 (d, J = 1.4 Hz, 2H), 8.17 (s, 2H), 7.62 (dd, J = 7.5, 1.4 Hz,2H), 7.53 (t, J = 7.5 Hz, 2H), 7.31 (dd, J = 7.5, 5.0 Hz, 6H), 7.26 – 7.16(m, 2H), 5.00 (s, 1H), 2.58 (s, 18H), 1.43 (s, 18H), 1.34 – 1.10 (m, 8H),1.06 – 0.97 (m, 6H), 0.94 (t, J = 6.7 Hz, 12H), 0.75 – 0.67 (m, 2H).

[0116] 3) Synthesis method of Ir-14:

[0117] ;

[0118] Under a nitrogen atmosphere, 1 part of 3-methyl-5-trifluoromethyl-1H-indole, 1.2 parts of 1-bromo-2-fluorobenzene, and 1.2 parts of cesium carbonate were dispersed in a certain amount of N,N-dimethylformamide and stirred at 120°C for 12 hours. After the reaction was complete, the mixture was cooled to room temperature, a large amount of water was added, and stirring was continued for 1 hour. The mixture was then filtered. The filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid product (12).

[0119] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 354.3135 [M+H] +

[0120] ;

[0121] Under a nitrogen atmosphere, a mixture of 1 part intermediate (12), 0.1 part palladium acetate, 0.2 part tri-tert-butylphosphine, and 2 parts cesium carbonate was dispersed in a certain amount of N,N'-dimethylacetamide and stirred at 140 degrees Celsius for 12 hours. After the reaction was completed, a large amount of water was added, and the filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid (13).

[0122] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 274.3632 [M+H] +

[0123] ;

[0124] One part of intermediate (13) and 1.2 parts of N-bromosuccinimide were dispersed in a certain amount of dichloromethane and stirred at room temperature for 6 hours. After the reaction was completed, the solvent was concentrated, and a large amount of methanol was added. The mixture was then filtered to collect a large amount of white precipitate. After washing three times with methanol, a white product (14) was collected.

[0125] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 366.1825 [M+H] +

[0126] ;

[0127] Under a nitrogen atmosphere, 1 part of intermediate (14), 1.1 parts of pinacol diborate, 0.05 parts of 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride, and 4 parts of potassium acetate were dispersed in a certain amount of dioxane and stirred at 110°C for 12 hours. After the reactants had reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was purified by silica gel column chromatography to obtain a white solid product (15).

[0128] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 414.1760 [M+H] +

[0129] ;

[0130] Under a nitrogen atmosphere, 1 part of intermediate (15), 1.2 parts of 2-bromo-4-m-trimethylpyridine, 0.05 parts of tetraphenylphosphine palladium, and 1.5 parts of potassium carbonate were dispersed in a certain amount of tetrahydrofuran / water = 3:1 mixed solvent and stirred at 75 degrees Celsius for 12 hours. After the starting materials reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was further purified by column chromatography to obtain a white ligand (16).

[0131] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 483.7620 [M+H] +

[0132] ;

[0133] 2.1 parts of ligand (16) and 1 part of iridium trichloride were dispersed in a certain amount of ethylene glycol ethyl ether / water = 3:1 mixed solvent. After purging with nitrogen three times, the mixture was stirred at 110 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, the mixture was filtered, the filter cake was collected, washed twice with petroleum ether, and dried to obtain a yellow solid product (17).

[0134] ;

[0135] One part of intermediate (17), 1.2 parts of 2,2,6,6-tetramethylheptane-3,5-dione, and 5 parts of potassium carbonate were dispersed in a certain amount of ethylene glycol diethyl ether. After purging with nitrogen three times, the mixture was stirred at 140°C for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was filtered. The filter cake was collected and then purified by column chromatography. The yellow iridium complex Ir-14 was obtained.

[0136] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 1340.4876 [M+H] +

[0137] 1H NMR (500 MHz, CDCl3) δ 8.68 (d, J = 15.0 Hz, 2H), 8.60 (d, J = 2.9Hz, 2H), 8.04 – 7.96 (m, 4H), 7.91 (s, 4H), 7.44 (s, 2H), 7.01 (s, 4H), 4.64(s, 1H), 2.92 (s, 12H), 2.58 (s, 6H), 2.48 (s, 6H), 2.34 (s, 6H), 0.99 (s,18H).

[0138] 4) Synthesis method of Ir-16:

[0139] ;

[0140] Under a nitrogen atmosphere, 4-tert-butylaniline, 1-bromo-2-iodobenzene, 0.05 parts of tris(dibenzylacetone)palladium, 0.1 parts of 1,1'-bis(diphenylphosphine)ferrocene, and 3 parts of sodium tert-butoxide were dissolved in an appropriate amount of toluene solvent, and the mixture was heated and stirred at 100°C for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered with diatomaceous earth, and washed with ethyl acetate. The organic phase was then separated by liquid chromatography, washed three times with saturated brine, dried over anhydrous magnesium sulfate, and the solvent was removed by rotary evaporation using silica gel adsorption. The product was then purified by silica gel column chromatography to obtain a white solid product. One part of the obtained product, 0.05 parts of palladium acetate, 0.1 parts of tri-tert-butylphosphine, and 3 parts of cesium carbonate were dispersed in an appropriate amount of N,N'-dimethylacetamide, and the mixture was heated to 140°C under a nitrogen atmosphere for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was stirred for 0.5 hours. The precipitate was then directly filtered off. The precipitate was separated by a simple silica gel short column to obtain a white solid product (18).

[0141] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 238.3654 [M+H] +

[0142] ;

[0143] Under a nitrogen atmosphere, 1 part of intermediate (18), 1.2 parts of 1-bromo-2-fluoro-4-methylbenzene, and 1.2 parts of cesium carbonate were dispersed in a certain amount of N,N-dimethylformamide and stirred at 120 degrees Celsius for 12 hours. After the reaction was complete, the mixture was cooled to room temperature, a large amount of water was added, and stirring was continued for 1 hour. The mixture was then filtered. The filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid product (19).

[0144] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 406.3728 [M+H] +

[0145] ;

[0146] Under a nitrogen atmosphere, a mixture of 1 part intermediate (19), 0.1 part palladium acetate, 0.2 part tri-tert-butylphosphine, and 2 parts cesium carbonate was dispersed in a certain amount of N,N'-dimethylacetamide and stirred at 140 degrees Celsius for 12 hours. After the reaction was completed, a large amount of water was added, and the filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid (20).

[0147] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 326.4623 [M+H] +

[0148] ;

[0149] One part of intermediate (20) and 1.2 parts of N-bromosuccinimide were dispersed in a certain amount of dichloromethane and stirred at room temperature for 6 hours. After the reaction was completed, the solvent was concentrated, and a large amount of methanol was added. The mixture was then filtered to collect a large amount of white precipitate. After washing three times with methanol, a white product (21) was collected.

[0150] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 403.3527 [M+H] +

[0151] ;

[0152] Under a nitrogen atmosphere, 1 part of intermediate (21), 1.1 parts of pinacol diborate, 0.05 parts of 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride, and 4 parts of potassium acetate were dispersed in a certain amount of dioxane and stirred at 110°C for 12 hours. After the reactants had reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was purified by silica gel column chromatography to obtain a white solid product (22).

[0153] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 452.4212 [M+H] +

[0154] ;

[0155] Under a nitrogen atmosphere, 1 part of intermediate (22), 1.2 parts of 2-bromo-4-(2,6-dimethylphenyl)pyridine, 0.05 parts of tetraphenylphosphine palladium, and 1.5 parts of potassium carbonate were dispersed in a certain amount of tetrahydrofuran / water = 3:1 mixed solvent and stirred at 75 degrees Celsius for 12 hours. After the starting materials reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was further purified by column chromatography to obtain a white ligand (23).

[0156] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 507.6932 [M+H] +

[0157] ;

[0158] 2.1 parts of ligand (23) and 1 part of iridium trichloride were dispersed in a certain amount of ethylene glycol ethyl ether / water = 3:1 mixed solvent. After purging with nitrogen three times, the mixture was stirred at 110 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, the mixture was filtered, the filter cake was collected, washed twice with petroleum ether, and dried to obtain a dark yellow solid product (24).

[0159] ;

[0160] One part of intermediate (24), 1.2 parts of 2,2,6,6-tetramethylheptane-3,5-dione, and 5 parts of potassium carbonate were dispersed in a certain amount of ethylene glycol diethyl ether. After purging with nitrogen three times, the mixture was stirred at 140°C for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was filtered. The filter cake was collected and then purified by column chromatography to obtain the yellow iridium complex Ir-16.

[0161] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 1388.8735 [M+H] +

[0162] 1H NMR (500 MHz, CDCl3) δ 8.68 (d, J = 15.0 Hz, 2H), 8.60 (d, J = 2.9Hz, 2H), 8.36 (d, J = 2.9 Hz, 2H), 8.05 – 7.96 (m, 4H), 7.89 (d, J = 2.9 Hz,2H), 7.53 (dd, J = 15.9, 13.9 Hz, 2H), 7.44 (s, 2H), 7.41 – 7.27 (m, 8H),5.32 (s, 1H), 2.58 (s, 18H), 2.50 (s, 6H), 1.32 (s, 18H), 0.99 (s, 18H).

[0163] 5) Synthesis method of Ir-29:

[0164] ;

[0165] Under a nitrogen atmosphere, 4-tert-butylaniline, 1.2 parts of 3-bromo-2-iodothiophene, 0.05 parts of tris(dibenzylacetone)palladium, 0.1 parts of 1,1'-bis(diphenylphosphine)ferrocene, and 3 parts of sodium tert-butoxide were dissolved in an appropriate amount of toluene solvent and reacted at 100°C with stirring for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered with diatomaceous earth, and washed with ethyl acetate. The organic phase was then separated by liquid chromatography, washed three times with saturated brine, dried over anhydrous magnesium sulfate, and the solvent was removed by rotary evaporation with silica gel adsorption. The product was then purified by silica gel column chromatography to obtain a pale yellow solid product. One part of the obtained product, 0.05 parts of palladium acetate, 0.1 parts of tri-tert-butylphosphine, and 3 parts of cesium carbonate were dispersed in an appropriate amount of N,N'-dimethylacetamide and heated to 140°C under a nitrogen atmosphere for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and after stirring for 0.5 hours, the precipitate was directly filtered off. The precipitate was separated by a simple silica gel short column to obtain a white solid product (25).

[0166] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 228.3475 [M+H] +

[0167] ;

[0168] Under a nitrogen atmosphere, 1 part of intermediate (25), 1.2 parts of 1-bromo-2-fluoro-4-methylbenzene, and 1.2 parts of cesium carbonate were dispersed in a certain amount of N,N-dimethylformamide and stirred at 120 degrees Celsius for 12 hours. After the reaction was complete, the mixture was cooled to room temperature, a large amount of water was added, and stirring was continued for 1 hour. The mixture was then filtered. The filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid product (26).

[0169] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 398.3645 [M+H] +

[0170] ;

[0171] Under a nitrogen atmosphere, a mixture of 1 part intermediate (26), 0.1 part palladium acetate, 0.2 part tri-tert-butylphosphine, and 2 parts cesium carbonate was dispersed in a certain amount of N,N'-dimethylacetamide and stirred at 140 degrees Celsius for 12 hours. After the reaction was completed, a large amount of water was added, and the filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid (27).

[0172] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 317.4532 [M+H] +

[0173] ;

[0174] One part of intermediate (27) and 1.2 parts of N-bromosuccinimide were dispersed in a certain amount of dichloromethane and stirred at room temperature for 6 hours. After the reaction was completed, the solvent was concentrated, and a large amount of methanol was added. The mixture was then filtered to collect a large amount of white precipitate. After washing three times with methanol, a white product (28) was collected.

[0175] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 396.3545 [M+H] +

[0176] ;

[0177] Under a nitrogen atmosphere, 1 part of intermediate (28), 1.1 parts of pinacol diborate, 0.05 parts of 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride, and 4 parts of potassium acetate were dispersed in a certain amount of dioxane and stirred at 110°C for 12 hours. After the reactants had reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was purified by silica gel column chromatography to obtain a white solid product (29).

[0178] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 444.4135 [M+H] +

[0179] ;

[0180] Under a nitrogen atmosphere, 1 part of intermediate (29), 1.2 parts of 2-bromo-4-m-trimethylpyridine, 0.05 parts of tetraphenylphosphine palladium, and 1.5 parts of potassium carbonate were dispersed in a certain amount of tetrahydrofuran / water = 3:1 mixed solvent and stirred at 75 degrees Celsius for 12 hours. After the starting materials reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was further purified by column chromatography to obtain a white ligand (30).

[0181] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 513.7234 [M+H] +

[0182] After obtaining the main ligand, the corresponding complex is synthesized:

[0183] ;

[0184] 2.1 parts of ligand (30) and 1 part of iridium trichloride were dispersed in a certain amount of ethylene glycol ethyl ether / water = 3:1 mixed solvent. After purging with nitrogen three times, the mixture was stirred at 110 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, the mixture was filtered, the filter cake was collected, washed twice with petroleum ether, and dried to obtain a brown solid product (31).

[0185] ;

[0186] One part of intermediate (31), 1.2 parts of 2-phenylpyridine, and 5 parts of potassium carbonate were dispersed in a certain amount of ethylene glycol ethyl ether. After purging with nitrogen three times, the mixture was stirred at 140 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, the mixture was filtered, the filter cake was collected, and then purified by column chromatography. The orange iridium complex Ir-29 was obtained.

[0187] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 1369.8235 [M+H] +

[0188] 1H NMR (500 MHz, CDCl3) δ 8.68 (d, J = 15.0 Hz, 2H), 8.60 (d, J = 2.9Hz, 2H), 8.55 - 8.35 (m, 3H), 8.36 (d, J = 2.9 Hz, 2H), 8.00 (dd, J = 14.9,3.0 Hz, 2H), 7.89 (d, J = 2.9 Hz, 2H), 7.70 (d, J = 15.0 Hz, 2H), 7.55 (t, J= 7.3 Hz, 2H), 7.51 – 7.46 (m, 1H), 7.44 (s, 2H), 7.42 – 7.32 (m, 1H), 7.31(d, J = 15.0 Hz, 2H), 7.14 (dd, J = 7.5, 1.4 Hz, 1H), 7.01 (s, 4H), 6.90 –6.78 (m, 1H), 2.92 (s, 12H), 2.58 (s, 6H), 2.48 (s, 6H), 1.32 (s, 18H).

[0189] 6) Synthesis method of Ir-33:

[0190] ;

[0191] Under a nitrogen atmosphere, 1 part of 4-trifluoromethylaniline, 1.2 parts of 3-bromo-2-iodobenzo[b]thiophene, 0.05 parts of tridibenzylacetone dipalladium, 0.1 parts of 1,1'-bis(diphenylphosphine)ferrocene, and 3 parts of sodium tert-butoxide were dissolved in an appropriate amount of toluene solvent, and the mixture was heated and stirred at 100°C for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered with diatomaceous earth, and washed with ethyl acetate. The organic phase was then separated by liquid chromatography, washed three times with saturated brine, dried over anhydrous magnesium sulfate, and the solvent was removed by rotary evaporation using silica gel adsorption. The product was then purified by silica gel column chromatography to obtain a pale yellow solid product. 1 part of the obtained product, 0.05 parts of palladium acetate, 0.1 parts of tritert-butylphosphine, and 3 parts of cesium carbonate were dispersed in an appropriate amount of N,N'-dimethylacetamide, and the mixture was heated to 140°C under a nitrogen atmosphere for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was stirred for 0.5 hours. The precipitate was then directly filtered off. The precipitate was separated by a simple silica gel short column to obtain a white solid product (32).

[0192] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 292.2932 [M+H] +

[0193] ;

[0194] Under a nitrogen atmosphere, 1 part of intermediate (32), 1.2 parts of 1-bromo-2-fluoro-4-methylbenzene, and 1.2 parts of cesium carbonate were dispersed in a certain amount of N,N-dimethylformamide and stirred at 120 degrees Celsius for 12 hours. After the reaction was complete, the mixture was cooled to room temperature, a large amount of water was added, and stirring was continued for 1 hour. The mixture was then filtered. The filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid product (33).

[0195] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 461.3135 [M+H] +

[0196] ;

[0197] Under a nitrogen atmosphere, a mixture of 1 part intermediate (33), 0.1 part palladium acetate, 0.2 part tri-tert-butylphosphine, and 2 parts cesium carbonate was dispersed in a certain amount of N,N'-dimethylacetamide and stirred at 140 degrees Celsius for 12 hours. After the reaction was completed, a large amount of water was added, and the filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid (34).

[0198] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 380.4135 [M+H] +

[0199] ;

[0200] One part of intermediate (34) and 1.2 parts of N-bromosuccinimide were dispersed in a certain amount of dichloromethane and stirred at room temperature for 6 hours. After the reaction was completed, the solvent was concentrated, and a large amount of methanol was added. The mixture was then filtered to collect a large amount of white precipitate. After washing three times with methanol, a white product (35) was collected.

[0201] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 457.3121 [M+H] +

[0202] ;

[0203] Under a nitrogen atmosphere, 1 part of intermediate (35), 1.1 parts of pinacol diborate, 0.05 parts of 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride, and 4 parts of potassium acetate were dispersed in a certain amount of dioxane and stirred at 110°C for 12 hours. After the reactants had reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was purified by silica gel column chromatography to obtain a white solid product (36).

[0204] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 504.3635 [M+H] +

[0205] ;

[0206] Under a nitrogen atmosphere, 1 part of intermediate (36), 1.2 parts of 2-bromo-4-m-trimethylpyridine, 0.05 parts of tetraphenylphosphine palladium, and 1.5 parts of potassium carbonate were dispersed in a certain amount of tetrahydrofuran / water = 3:1 mixed solvent and stirred at 75 degrees Celsius for 12 hours. After the starting materials reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was further purified by column chromatography to obtain a white ligand (37).

[0207] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 575.7620 [M+H] +

[0208] ;

[0209] 2.1 parts of ligand (37) and 1 part of iridium trichloride were dispersed in a certain amount of ethylene glycol ethyl ether / water = 3:1 mixed solvent. After purging with nitrogen three times, the mixture was stirred at 110 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, the mixture was filtered, the filter cake was collected, washed twice with petroleum ether, and dried to obtain a brown solid product (38).

[0210] ;

[0211] One part of intermediate (38), 1.2 parts of 2,4-diphenylpyridine, and 5 parts of potassium carbonate were dispersed in a certain amount of ethylene glycol ethyl ether. After purging with nitrogen three times, the mixture was stirred at 140°C for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was filtered. The filter cake was collected and then purified by column chromatography. The orange-red iridium complex Ir-33 was obtained.

[0212] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 1570.3666 [M+H] +

[0213] 1H NMR (500 MHz, Chloroform ) δ 8.78 (m, 3H), 8.80 (d, J = 2.9 Hz,2H), 8.60 (d, J = 2.9 Hz, 1H), 8.38 – 8.23 ​​(m, 4H), 8.24 (d, J = 2.9 Hz, 2H),8.20 (s, 2H), 8.00 (dd, J = 14.9, 3.0 Hz, 1H), 7.90 – 7.82 (m, 4H), 7.80 –7.70 (m, 2H), 7.65 – 7.33 (m, 6H), 7.3 (td, J = 15.0, 3.0 Hz, 2H), 7.22 (s,2H), 7.10 (td, J = 15.0, 3.0 Hz, 2H), 7.01 (s, 4H), 3.20 (s, 12H), 2.85 (s,6H), 2.33 (s, 6H).

[0214] 7) Synthesis method of Ir-43:

[0215] ;

[0216] Under a nitrogen atmosphere, 1 part of 4-isopropylaniline, 1.2 parts of 3-bromo-2-iodo-5-methylthiophene, 0.05 parts of tris(dibenzylacetone)palladium, 0.1 parts of 1,1'-bis(diphenylphosphine)ferrocene, and 3 parts of sodium tert-butoxide were dissolved in an appropriate amount of toluene solvent. The mixture was heated and stirred at 100°C for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered through diatomaceous earth, and washed with ethyl acetate. The organic phase was then separated by liquid chromatography, washed three times with saturated brine, dried over anhydrous magnesium sulfate, and the solvent was removed by rotary evaporation using silica gel adsorption. The product was then purified by silica gel column chromatography to obtain a pale yellow solid. One part of the obtained product, 0.05 parts of palladium acetate, 0.1 parts of tri-tert-butylphosphine, and 3 parts of cesium carbonate were dispersed in an appropriate amount of N,N'-dimethylacetamide and heated to 140°C under a nitrogen atmosphere for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was stirred for 0.5 hours. The precipitate was then directly filtered off. The precipitate was separated by a simple silica gel short column to obtain a white solid product (39).

[0217] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 230.3425 [M+H] +

[0218] ;

[0219] Under a nitrogen atmosphere, 1 part of intermediate (39), 1.2 parts of 1-bromo-2-fluoro-4-methylbenzene, and 1.2 parts of cesium carbonate were dispersed in a certain amount of N,N'-dimethylformamide and stirred at 120 degrees Celsius for 12 hours. After the reaction was complete, the mixture was cooled to room temperature, a large amount of water was added, and stirring was continued for 1 hour. The mixture was then filtered. The filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid product (40).

[0220] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 398.3001 [M+H] +

[0221] ;

[0222] Under a nitrogen atmosphere, a mixture of 1 part intermediate (40), 0.1 part palladium acetate, 0.2 part tri-tert-butylphosphine, and 2 parts cesium carbonate was dispersed in a certain amount of N,N'-dimethylacetamide and stirred at 140 degrees Celsius for 12 hours. After the reaction was completed, a large amount of water was added, and the filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid (41).

[0223] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 318.1243 [M+H] +

[0224] ;

[0225] One part of intermediate (41) and 1.2 parts of N-bromosuccinimide were dispersed in a certain amount of dichloromethane and stirred at room temperature for 6 hours. After the reaction was completed, the solvent was concentrated, and a large amount of methanol was added. The mixture was then filtered to collect a large amount of white precipitate. After washing three times with methanol, a white product (42) was collected.

[0226] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 397.1335 [M+H] +

[0227] ;

[0228] Under a nitrogen atmosphere, 1 part of intermediate (42), 1.1 parts of pinacol diborate, 0.05 parts of 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride, and 4 parts of potassium acetate were dispersed in a certain amount of dioxane and stirred at 110 degrees Celsius for 12 hours. After the reactants had reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was purified by silica gel column chromatography to obtain a white solid product (43).

[0229] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 445.3835 [M+H] +

[0230] ;

[0231] Under a nitrogen atmosphere, 1 part of intermediate (43), 1.2 parts of 2-bromo-4-(trimethylsilyl)pyridine, 0.05 parts of tetraphenylphosphine palladium, and 1.5 parts of potassium carbonate were dispersed in a certain amount of tetrahydrofuran / water = 3:1 mixed solvent and stirred at 75 degrees Celsius for 12 hours. After the starting materials reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was further purified by column chromatography to obtain a white ligand (44).

[0232] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 467.3363 [M+H] +

[0233] ;

[0234] 2.1 parts of ligand (44) and 1 part of iridium trichloride were dispersed in a certain amount of ethylene glycol ethyl ether / water = 3:1 mixed solvent. After purging with nitrogen three times, the mixture was stirred at 110 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, the mixture was filtered, the filter cake was collected, washed twice with petroleum ether, and dried to obtain a yellow-brown solid product (45).

[0235] ;

[0236] One part of intermediate (45), 1.2 parts of 2,2,6,6-tetramethylheptane-3,5-dione, and 5 parts of potassium carbonate were dispersed in a certain amount of ethylene glycol diethyl ether. After purging with nitrogen three times, the mixture was stirred at 140°C for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was filtered. The filter cake was collected and then purified by column chromatography to obtain the yellow iridium complex Ir-43.

[0237] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 1308.1220 [M+H] +

[0238] 1H NMR (500 MHz, CDCl3) δ 8.91 (d, J = 15.0 Hz, 2H), 8.38 – 8.14 (m,2H), 7.90 – 7.79 (m, 4H), 7.70 (d, J = 2.9 Hz, 2H), 7.64 (s, 2H), 7.15 (dd, J= 15.0, 3.1 Hz, 2H), 5.25 (s, 1H), 3.01 – 2.70 (m, 2H), 2.44 (s, 6H), 2.01(s, 6H),1.52 (s, 18H), 1.20 (d, J = 12.8 Hz, 12H), 0.33 (s, 18H).

[0239] 8) Synthesis method of Ir-55:

[0240] ;

[0241] Under a nitrogen atmosphere, 1 part of 4-isopropylaniline, 1.2 parts of 3-bromo-2-iodothiophene, 0.05 parts of tris(dibenzylacetone)palladium, 0.1 parts of 1,1'-bis(diphenylphosphine)ferrocene, and 3 parts of sodium tert-butoxide were dissolved in an appropriate amount of toluene solvent. The mixture was heated and stirred at 100°C for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered with diatomaceous earth, and washed with ethyl acetate. The organic phase was then separated by liquid chromatography, washed three times with saturated brine, dried over anhydrous magnesium sulfate, and the solvent was removed by rotary evaporation using silica gel adsorption. The product was then purified by silica gel column chromatography to obtain a pale yellow solid. One part of the obtained product, 0.05 parts of palladium acetate, 0.1 parts of tri-tert-butylphosphine, and 3 parts of cesium carbonate were dispersed in an appropriate amount of N,N'-dimethylacetamide and heated to 140°C under a nitrogen atmosphere for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was stirred for 0.5 hours. The precipitate was then directly filtered off. The precipitate was separated by a simple silica gel short column to obtain a pale yellow solid product (46).

[0242] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 266.3736 [M+H] +

[0243] ;

[0244] Under a nitrogen atmosphere, 1 part of intermediate (46), 1.2 parts of 1-bromo-2-fluoro-4-trifluoromethylbenzene, and 1.2 parts of cesium carbonate were dispersed in a certain amount of N,N-dimethylformamide and stirred at 120 degrees Celsius for 12 hours. After the reaction was complete, the mixture was cooled to room temperature, a large amount of water was added, and stirring was continued for 1 hour. The mixture was then filtered. The filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid product (47).

[0245] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 487.3725 [M+H] +

[0246] ;

[0247] Under a nitrogen atmosphere, a mixture of 1 part intermediate (47), 0.1 part palladium acetate, 0.2 part tri-tert-butylphosphine, and 2 parts cesium carbonate was dispersed in a certain amount of N,N'-dimethylacetamide and stirred at 140 degrees Celsius for 12 hours. After the reaction was completed, a large amount of water was added, and the filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid (48).

[0248] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 408.3632 [M+H] +

[0249] ;

[0250] One part of intermediate (48) and 1.2 parts of N-bromosuccinimide were dispersed in a certain amount of dichloromethane and stirred at room temperature for 6 hours. After the reaction was completed, the solvent was concentrated, and a large amount of methanol was added. The mixture was then filtered to collect a large amount of white precipitate. After washing three times with methanol, a white product (49) was collected.

[0251] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 486.3520 [M+H] +

[0252] ;

[0253] Under a nitrogen atmosphere, 1 part of intermediate (49), 1.1 parts of pinacol diborate, 0.05 parts of 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride, and 4 parts of potassium acetate were dispersed in a certain amount of dioxane and stirred at 110°C for 12 hours. After the reactants had reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was purified by silica gel column chromatography to obtain a white solid product (50).

[0254] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 534.4225 [M+H] +

[0255] ;

[0256] Under a nitrogen atmosphere, 1 part of intermediate (50), 1.2 parts of 2-bromo-4-(trimethylsilyl)pyridine, 0.05 parts of tetraphenylphosphine palladium, and 1.5 parts of potassium carbonate were dispersed in a certain amount of tetrahydrofuran / water = 3:1 mixed solvent and stirred at 75 degrees Celsius for 12 hours. After the starting materials reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was further purified by column chromatography to obtain a white ligand (51).

[0257] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 556.72 [M+H] +

[0258] ;

[0259] 2.1 parts of ligand (51) and 1 part of iridium trichloride were dispersed in a certain amount of ethylene glycol ethyl ether / water = 3:1 mixed solvent. After purging with nitrogen three times, the mixture was stirred at 110 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, the mixture was filtered, the filter cake was collected, washed twice with petroleum ether, and dried to obtain a yellow-brown solid product (52).

[0260] ;

[0261] One part of intermediate (52), 1.2 parts of 2,2,6,6-tetramethylheptane-3,5-dione, and 5 parts of potassium carbonate were dispersed in a certain amount of ethylene glycol diethyl ether. After purging with nitrogen three times, the mixture was stirred at 140°C for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was filtered. The filter cake was collected and then purified by column chromatography. The orange-red iridium complex Ir-55 was obtained.

[0262] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 1488.9235 [M+H] +

[0263] 1H NMR (500 MHz, CDCl3) δ 8.50 – 8.40 (m, 4H), 8.24 – 8.17 (m, 2H), 7.92 – 7.81 (m, 2H), 7.80 – 7.70 (m, 6H), 7.56 (td, J = 15.0, 3.0 Hz, 2H), 7.36 – 7.17 (m, 4H), 5.30 (s, 1H), 3.04 – 2.62 (m, 2H), 1.33 (s, 18H), 1.20 (d, J = 12.8 Hz, 12H), 0.33 (s, 18H).

[0264] 9) Synthesis method of Ir-66:

[0265] ;

[0266] Under a nitrogen atmosphere, 1 part of 3-fluoroaniline, 1.2 parts of 3-bromo-2-iodo-5-methylfuran, 0.05 parts of tris(dibenzylacetone)palladium, 0.1 parts of 1,1'-bis(diphenylphosphine)ferrocene, and 3 parts of sodium tert-butoxide were dissolved in an appropriate amount of toluene solvent. The mixture was heated and stirred at 100°C for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered through diatomaceous earth, and washed with ethyl acetate. The organic phase was then separated by liquid chromatography, washed three times with saturated brine, dried over anhydrous magnesium sulfate, and the solvent was removed by rotary evaporation using silica gel adsorption. The product was then purified by silica gel column chromatography to obtain a white solid product. 1 part of the obtained product, 0.05 parts of palladium acetate, 0.1 parts of tri-tert-butylphosphine, and 3 parts of cesium carbonate were dispersed in an appropriate amount of N,N'-dimethylacetamide. The mixture was heated to 140°C under a nitrogen atmosphere and reacted for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was stirred for 0.5 hours. The precipitate was then directly filtered off. The precipitate was separated by a simple silica gel short column to obtain a white solid product (53).

[0267] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 190.1925 [M+H] +

[0268] ;

[0269] Under a nitrogen atmosphere, 1 part of intermediate (53), 1.2 parts of 1-bromo-2-fluoro-4-methylbenzene, and 1.2 parts of cesium carbonate were dispersed in a certain amount of N,N-dimethylformamide and stirred at 120 degrees Celsius for 12 hours. After the reaction was complete, the mixture was cooled to room temperature, a large amount of water was added, and stirring was continued for 1 hour. The mixture was then filtered. The filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid product (54).

[0270] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 358.2125 [M+H] +

[0271] ;

[0272] Under a nitrogen atmosphere, a mixture of 1 part intermediate (54), 0.1 part palladium acetate, 0.2 part tri-tert-butylphosphine, and 2 parts cesium carbonate was dispersed in a certain amount of N,N'-dimethylacetamide and stirred at 140 degrees Celsius for 12 hours. After the reaction was completed, a large amount of water was added, and the filter cake was washed twice with water, ethanol, and petroleum ether, respectively, and dried to obtain a white solid (55).

[0273] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 278.3130 [M+H] +

[0274] ;

[0275] One part of intermediate (55) and 1.2 parts of N-bromosuccinimide were dispersed in a certain amount of dichloromethane and stirred at room temperature for 6 hours. After the reaction was completed, the solvent was concentrated, and a large amount of methanol was added. The mixture was then filtered to collect a large amount of white precipitate. After washing three times with methanol, a white product (56) was collected.

[0276] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 356.1825 [M+H] +

[0277] ;

[0278] Under a nitrogen atmosphere, 1 part of intermediate (56), 1.1 parts of pinacol diborate, 0.05 parts of 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride, and 4 parts of potassium acetate were dispersed in a certain amount of dioxane and stirred at 110°C for 12 hours. After the reactants had reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was purified by silica gel column chromatography to obtain a white solid product (57).

[0279] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 404.2625 [M+H] +

[0280] ;

[0281] Under a nitrogen atmosphere, 1 part of intermediate (57), 1.2 parts of 2-bromo-4-isobutylpyridine, 0.05 parts of tetraphenylphosphine palladium, and 1.5 parts of potassium carbonate were dispersed in a certain amount of tetrahydrofuran / water = 3:1 mixed solvent and stirred at 75 degrees Celsius for 12 hours. After the starting materials reacted completely, the mixture was cooled to room temperature, the reaction solution was quenched with water, and extracted three times with dichloromethane and water. The organic phases were combined, concentrated, and column chromatography was performed. The crude product was further purified by column chromatography to obtain a white ligand (58).

[0282] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 411.4945 [M+H] +

[0283] ;

[0284] 2.1 parts of ligand (58) and 1 part of iridium trichloride were dispersed in a certain amount of ethylene glycol ethyl ether / water = 3:1 mixed solvent. After purging with nitrogen three times, the mixture was stirred at 110 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, the mixture was filtered, the filter cake was collected, washed twice with petroleum ether, and dried to obtain a yellow solid product (59).

[0285] ;

[0286] One part of intermediate (59), 1.2 parts of 3,7-diethylnonane-4,6-dione, and 5 parts of potassium carbonate were dispersed in a certain amount of ethylene glycol diethyl ether. After purging with nitrogen three times, the mixture was stirred at 140°C for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was filtered. The filter cake was collected and then purified by column chromatography. The orange-red iridium complex Ir-66 was obtained.

[0287] ESI-HRMS (High-resolution electrospray ionization mass spectrometry) [m / z]: 1223.4642 [M+H] +

[0288] 1H NMR (500 MHz, Chloroform) δ 8.80 (d, J = 15.0 Hz, 2H), 8.60 – 8.50 (m, 2H), 7.61 (dd, J = 15.0, 10.1 Hz, 2H), 7.44 (s, 2H), 7.14 (ddd, J = 17.9,15.4, 9.1 Hz, 4H), 6.51 (s, 2H), 4.84 (s, 1H), 3.21-3.08 (m, 5H), 2.60 – 2.25(m, 7H), 2.25 (s, 6H), 1.96 – 1.66 (m, 2H), 1.55 – 1.06 (m, 8H), 1.04-0.94(m, 12H), 0.87 (d, J = 12.5 Hz, 12H).

[0289] It should be noted that the above preparation methods are only examples, and the actual preparation of phosphorescent iridium complexes is not limited to the above methods, but may also be done by other methods.

[0290] A second aspect of the present invention also provides a luminescent material comprising a host material and a guest material, wherein the mass percentage of the guest material is 4-10%, preferably 8%; the guest material is the aforementioned phosphorescent iridium complex, having a narrow spectral half-width and a low-intensity shoulder peak, and the luminescent material can be used as a luminescent functional layer in an organic electroluminescent device.

[0291] A third aspect of the present invention also provides an organic electroluminescent device, the device comprising a first electrode, a second electrode and one or more light-emitting functional layers located between the first electrode and the second electrode, wherein at least one light-emitting functional layer is prepared from the aforementioned light-emitting material, or at least one light-emitting functional layer is prepared from the aforementioned phosphorescent iridium metal complex.

[0292] In a preferred embodiment, the organic electroluminescent device includes a substrate and a first electrode, a plurality of light-emitting functional layers, and a second electrode sequentially formed on the substrate. The plurality of light-emitting functional layers include a hole transport region, a light-emitting layer, and an electron transport region. The hole transport region is formed on the anode layer, the cathode layer is formed on the electron transport region, and the light-emitting layer is located between the hole transport region and the electron transport region. The light-emitting layer contains the aforementioned phosphorescent iridium complex or is prepared from the aforementioned light-emitting material. This organic electroluminescent device exhibits excellent color purity and high external quantum efficiency.

[0293] To further illustrate the phosphorescent iridium complex, luminescent material, and organic electroluminescent device provided by the present invention, the following embodiments are provided. Example 1

[0294] An electroluminescent device, the structure of which is as follows: Figure 1 As shown, from bottom to top, it includes a substrate 1, a hole injection layer 2, a hole transport layer 3, a light-emitting layer 4, an electron transport layer 5, an electron injection layer 6, and a metal electrode 7.

[0295] Specifically, this electroluminescent device uses transparent ITO glass as a substrate, and various organic layers, a LiF electron injection layer, and a metal Al electrode are sequentially deposited on the substrate using vacuum deposition equipment. Specifically, a hole injection layer is formed by depositing HATCN, a hole transport layer by depositing TAPC, an electron transport layer by depositing TmPyPB, an electron injection layer by depositing LiF, and a light-emitting layer is formed by depositing an EML. The EML uses CBP as the host material and Ir-1 as the guest material, with the host material accounting for 92% by weight and the guest material accounting for 8% by weight.

[0296] The specific materials used in each layered structure are as follows:

[0297] ;

[0298] The specific thicknesses of each layered structure in this electroluminescent device are: [ITO / HATCN (6 nm) / TAPC (50 nm) / EML (20 nm) / TmPyPB (60 nm) / LiF (1 nm) / AL (100 nm)].

[0299] Examples 2-9

[0300] Examples 2-9 also illustrate electroluminescent devices. The layered structure of the electroluminescent devices in Examples 2-9 and the materials used in each layered structure are basically the same as those in Example 1. The difference is that the phosphorescent iridium complexes used as guest materials are Ir-7, Ir-14, Ir-16, Ir-29, Ir-33, Ir-43, Ir-55, and Ir-66.

[0301] Comparative Examples 1-6

[0302] Comparative Examples 1-6 were manufactured using the same processes and materials as in Example 1, except that in Comparative Examples 1-7, materials Ref-1, Ref-2, Ref-3, Ref-4, Ref-5, and Ref-6 were used as guest materials in the EML to replace Ir-1, respectively. The specific structural formulas of Ref-1, Ref-2, Ref-3, Ref-4, Ref-5, and Ref-6 are as follows:

[0303] , , , , , ;

[0304] The organic electroluminescent devices prepared in Examples 1-9 and Comparative Examples 1-6 were subjected to performance tests. The emission spectra and external quantum efficiency of the devices were simultaneously tested using a PR655 spectrometer and a KeithLey K 2400 digital source meter system. The performance tests were conducted in air. The results are shown in Table 1.

[0305] Table 1 Performance Testing of Electroluminescent Devices

[0306]

[0307] As shown in Table 1, in Examples 1-9, the spectral half-width is between 28-36 nm, which is relatively narrow, and the external quantum efficiency is ≥23.5%. It can be seen that the phosphorescent iridium complex prepared by the present invention can greatly improve the color purity and luminous efficiency of electroluminescent devices as a guest material.

[0308] In Comparative Example 1, the guest material Ref-1 has a classic Ir(ppy)3 structure, and the electroluminescent device exhibits a relatively wide full width at half maximum (FWHM) of 69 nm, which is typical for conventional complexes. In Comparative Example 2, the guest material Ref-2 is a complex with ppy as the first ligand and a ligand with a rigid indole-carbazole structure as the second ligand. The FWHM of the device is somewhat reduced, but still relatively wide at 60 nm. In Comparative Example 3, the guest material Ref-3 uses a ligand with a rigid indole-carbazole structure as the first ligand and ppy as the second ligand. The FWHM of the device is further reduced to 45 nm. This demonstrates that having two indole-carbazole ligands results in a narrowing effect on the spectrum.

[0309] In Comparative Examples 4-6, the Ref-4-6 complexes using a different coordination mode exhibited a wide half-width of about 70 nm in the electroluminescent device spectrum, which was not conducive to improving the color purity of the device.

[0310] also, Figure 2 The electroluminescence spectrum of Example 9 is shown below. Figure 4 This is a comparison of the electroluminescence spectra of Example 9 and Comparative Examples 1, 4, and 5. Figure 4 It can be seen that Example 9 has a narrower spectral half-width than Comparative Examples 1, 4, and 5.

[0311] In addition, the molecular-level orientation of the examples and comparative examples was tested, and the test results are as follows: Figure 3 The above, Figure 3 The left and right figures show the molecular-level orientation test results of ref-3, and the right figure shows the molecular-level orientation test results of Example 4. As can be seen from the figures, Example 4 has a higher molecular-level orientation, which can achieve a higher light extraction efficiency. Its device also has a higher external quantum efficiency than that of Comparative Example 3. It can be seen that when the R5 substitution site is in the direction of the Ir-N bond extension line of the coordination bond, it can improve the light extraction efficiency and external quantum efficiency of the device.

[0312] Clearly, the color purity and efficiency results of the electroluminescence in Examples 1-9 are significantly better than those in the corresponding comparative examples. This demonstrates that the present invention, through the interlocking of the two first ligands and the rigid structure of the ligands themselves, can greatly enhance the rigidity of the complex and suppress spectral broadening. In the corresponding electroluminescent devices, a half-maximum width at half maximum (FWHM) of 28-36 nm and a smaller shoulder peak intensity are achieved, significantly improving the color purity of the device. Simultaneously, the present invention also increases the axial length of the molecule by introducing substituents along the axial direction, thereby improving the horizontal orientation of the complex in the thin film and enhancing the light extraction efficiency of the iridium complex in the thin film, thus improving the external quantum efficiency of the device. Furthermore, by combining the electron-donating capabilities of the furan and thiophene rings and enhancing the bipolar transport characteristics of the complex, a high-color-purity, high-efficiency organic electroluminescent device can ultimately be achieved.

[0313] Therefore, by using the phosphorescent iridium complex of the present invention as the light-emitting layer material, an organic electroluminescent device with high color purity and high external quantum efficiency can be obtained.

[0314] In the description of the embodiments of the present invention, it should be noted that the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0315] It is understood that those skilled in the art can make equivalent substitutions or modifications to the technical solution and inventive concept of the present invention, and all such substitutions or modifications should fall within the protection scope of the appended claims.

Claims

1. A phosphorescent iridium complex, characterized in that: It is a complex having the general structure of formula (1): Among them, the L A is the first ligand, and its structural formula is as follows: A 5 shows: In L A 5, wherein Y is O or S; The R1 is a hydrogen atom, a deuterium atom, or a halogen atom; The R2 is selected from a halogen atom, an unsubstituted alkyl group having 1 to 20 carbon atoms, and an unsubstituted halogenated alkyl group having 1 to 20 carbon atoms; the number of the R2 is one or the maximum number of substitutions allowed in the ring structure; The R3 is selected from a hydrogen atom or an unsubstituted alkyl group having 1 to 20 carbon atoms; R4 is an unsubstituted alkyl group having 1 to 20 carbon atoms; The R5 is an unsubstituted alkyl group with 1 to 20 carbon atoms; the number of the R5 is one or the maximum number of substitutions allowed on the pyridine ring; The L B is the second ligand, and its structural formula is as follows (L B 1) or (L B 2): Among them, in the L B 1, the R9~R 10 Each is independently an unsubstituted alkyl group having 1 to 20 carbon atoms; In the L B 2, the R 11 ~R 12 Each is independently selected from a hydrogen atom, a deuterium atom, an unsubstituted alkyl group having 1 to 20 carbon atoms, and an unsubstituted aryl group having 1 to 20 carbon atoms.

2. The phosphorescent iridium complex according to claim 1, characterized in that The substitution site of the substituent R5 is located in the direction of the Ir-N bond axis of the coordination bond.

3. A phosphorescent iridium complex, characterized in that: The complex is selected from any one of the following chemical structural formulas:

4. A luminescent material, characterized in that: The invention comprises a host material and a guest material, wherein the guest material is the phosphorescent iridium complex according to any one of claims 1 to 3.

5. An organic electroluminescent device, characterized in that: It comprises one or more light-emitting functional layers, wherein at least one light-emitting functional layer is prepared from the light-emitting material according to claim 4.

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