Metal iridium complex, preparation method thereof and organic electroluminescent device

Abstract

The application provides a metal iridium complex, a preparation method thereof and an organic electroluminescent device, and belongs to the field of organic electroluminescent materials.The structure of the metal iridium complex is shown in formula I.The metal iridium complex improves the intermolecular spatial configuration, reduces the intermolecular bond angle, increases the life, has good spatial torsion capacity, thereby avoiding the carrier migration, and can be used as a specific doping material of a light-emitting layer and applied to the organic electroluminescent device, so that the wavelength of the metal iridium complex can be adjusted, the voltage is low, the power efficiency is obviously improved, the evaporation temperature is low, the photoelectrochemical stability is high, the light-emitting efficiency is high, the device life is long and the like.The preparation method of the metal iridium complex is simple in process, the product is high in purity, and is suitable for industrial production.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of organic electroluminescent materials, and particularly relates to a metal iridium complex, a preparation method thereof and an organic electroluminescent device. BACKGROUND

[0002] At present, the organic electroluminescent device (OLED) as a new generation of display technology has obtained more and more attention in the aspects of display and lighting technology, and has a very wide application prospect. However, compared with the market application requirements, the performance of the OLED device such as the luminous efficiency, the driving voltage and the service life still needs to be continuously strengthened and improved.

[0003] Generally, the basic structure of the OLED device is that various different functional organic material thin films are sandwiched in the middle of the metal electrode, under the driving of the current, the holes and the electrons are injected from the cathode and the anode respectively, the holes and the electrons are combined in the light-emitting layer after moving a distance, and are released in the form of light or heat, thereby the light-emitting of the OLED is generated. However, the organic functional material is the core component of the organic electroluminescent device, and the thermal stability, the photochemical stability, the electrochemical stability, the quantum yield, the film-forming stability, the crystallinity and the color saturation of the material are all the main factors affecting the performance of the device.

[0004] Generally, the organic functional material includes a fluorescent material and a phosphorescent material. The fluorescent material is usually an organic small molecule material, and generally can only utilize 25% singlet state to emit light, so the luminous efficiency is relatively low. The phosphorescent material can utilize the energy of 75% triplet state excitons in addition to 25% singlet state due to the spin-orbital coupling caused by the heavy atom effect, so the luminous efficiency is relatively high.

[0005] Compared with the fluorescent material, the phosphorescent material started relatively late, and the thermal stability, the service life and the color saturation of the currently disclosed organic phosphorescent material all need to be improved. CN107973823A discloses a kind of quinoline-based iridium compound, the color saturation and the device performance of the compound, especially the luminous efficiency and the device service life, all need to be improved; CN106459114A discloses a kind of iridium compound coordinated by a β-diketone coordination group, the sublimation temperature of the compound is high, the color saturation is not good, especially the luminous efficiency and the device service life of the device are not ideal, and further improvement is needed; CN111377969A discloses a kind of iridium complex of diphenylbenzofuran bisisoquinoline, the device performance of the material, especially the color saturation, cannot meet the display color gamut requirement of BT2020, and further improvement is needed.

[0006] Therefore, how to develop a metal iridium complex material with high luminous efficiency, low voltage, low evaporation temperature, high photochemical and electrochemical stability, high luminous efficiency and long device service life is a technical problem to be solved at present. SUMMARY

[0007] In view of the deficiencies of the prior art, the present application aims to provide a metal iridium complex, a preparation method thereof and an organic electroluminescent device.

[0008] To achieve the above object, the present application adopts the following technical solutions:

[0009] In one aspect, the present application provides a metal iridium complex, the structure of which is (La)2IrLb, specifically as shown in Formula I:

[0010] ;

[0011] wherein X is independently selected from O, S, Se, NRx, CRxRy, SiRxRy or GeRxRy, and Rx and Ry are each independently selected from hydrogen, methyl, -F, -D, -CN, -CD3 or phenyl;

[0012] R1, R2, R3, R4 and R5 are independently selected from any one or a combination of at least two of hydrogen, deuterium, halogen, -CN, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C3-C20 heterocyclyl, substituted or unsubstituted C6-C30 aryl, trimethylgermanium or trimethylsilicon;

[0013] each Ra is independently selected from any one or a combination of at least two of hydrogen, -D, -CN, -F, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C10 cycloalkyl, and Ra can be mono-substituted or poly-substituted;

[0014] ring A is independently selected from nothing, a substituted or unsubstituted C6-C18 aromatic ring, a C6-C18 heteroaromatic ring;

[0015] R6, R7 and R8 are each independently selected from any one or a combination of at least two of hydrogen, -D, -CN, -F, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted heterocycloalkyl;

[0016] in the substituted groups, the substituents are selected from -D, C1-C6 alkyl, -F, -CN, trimethylgermanium, trimethylsilicon, C3-C10 cycloalkyl, or a substituent connected by two or more substituents as shown above, or no substituent.

[0017] The hydrogen atoms in Formula I are unsubstituted by deuterium, partially substituted by deuterium or fully substituted by deuterium.

[0018] In the present application, D represents deuterium.

[0019] Further,

[0020] X is independently selected from O, S, Se, NRx, CRxRy, SiRxRy or GeRxRy, Rxand Ryare each independently selected from hydrogen, methyl;

[0021] R1, R2, R3, R4and R5are each independently selected from any one or a combination of at least two of hydrogen, -F, -CD3, -D, -CN, substituted or unsubstituted phenyl, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted butyl, substituted or unsubstituted pentyl, substituted or unsubstituted cyclopentyl, trimethylsilane or trimethylgermane;

[0022] Ra is independently selected from -F, -CD3, -D, -CN, substituted or unsubstituted phenyl, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted butyl, substituted or unsubstituted pentyl, substituted or unsubstituted cyclopentyl;

[0023] A is selected from absent, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl.

[0024] Further, Specific structures are preferably as follows:

[0025]

[0026] .

[0027] Preferably, R6, R7and R8are each independently selected from any one or a combination of at least two of hydrogen, -F, -D, -CN, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted butyl, substituted or unsubstituted pentyl, substituted or unsubstituted cyclopropyl, substituted or unsubstituted cyclopentyl.

[0028] Preferably, the substituted methyl can be -CD3, CF3or CD2F.

[0029] In the present application, Specific structures are preferably as follows:

[0030]

[0031] wherein D represents deuterium.

[0032] As a still further aspect of the present application, hydrogen in the above group or substituent group can be replaced with deuterium.

[0033] As a still further aspect of the present application, the metal iridium complex is selected from any one of the following structures, but not limited thereto:

[0034]

[0035] wherein D represents deuterium.

[0036] It should be noted that the above only lists some specific structural forms, but the series of metal iridium complexes are not limited to the above molecular structures, and other specific molecular structures can be obtained by simple changes of some simple groups and their substituted groups and substitution positions, which will not be described one by one.

[0037] A second object of the present application is to provide a method for preparing the above-mentioned metal iridium complex. The metal iridium complex of the present application can be prepared by methods known to those skilled in the art. Alternatively, the following reaction scheme is preferably used to prepare the metal iridium complex, comprising the following steps:

[0038] (1) providing a compound of formula II as shown below:

[0039]

[0040] (2) reacting the compound of formula II provided in step (1) with iridium trichloride to obtain a compound of formula III:

[0041]

[0042] (3) providing a compound of formula IV as shown below:

[0043]

[0044] (4) reacting the compound of formula IV provided in step (3) with the compound of formula III obtained in step (2) to obtain the metal iridium complex of formula I.

[0045]

[0046] wherein R1, R2, R3, R4, R5, Ra and A represent the same groups as defined above.

[0047] As a further aspect of the present application, in the reaction of the compound II provided in step (1) with iridium trichloride, the molar ratio of the compound II to the iridium trichloride is (2.2-2.5):1, for example 2.2:1, 2.3:1, 2.4:1 or 2.5:1.

[0048] Preferably, in the reaction of the compound II provided in step (1) with iridium trichloride (IrCl3), the solvent is a mixed solution of ethylene glycol ethyl ether and ultrapure water, and the volume ratio of the ethylene glycol ethyl ether to the ultrapure water is 3:1; the amount of the solvent is 30 times the mass of the iridium trichloride. In a nitrogen protection system, the compound II, IrCl3·3H2O (1 eq) is put into the reaction system, and a mixed solution of ethylene glycol ethyl ether and pure water is added. The reaction system is refluxed at 110°C for 24 hours under nitrogen protection, and then cooled to room temperature. A precipitate is separated out, which is suction filtered, washed with water, anhydrous ethanol and petroleum ether in sequence, and dried at 50°C for at least 10 hours to obtain the bridged ligand of formula III.

[0049] Further, in the reaction of the compound of formula IV provided in step (3) with the compound of formula III obtained in step (2), the molar ratio of the compound of formula III to the compound of formula IV is 1:2.5. The reaction is carried out in the presence of a base, the base used is anhydrous potassium carbonate or anhydrous sodium carbonate, and the reaction is carried out in a solvent, the solvent used is ethylene glycol ethyl ether, and the amount of the solvent used is 30 times the mass of the compound of formula III. The compound of formula III (1 eq) is taken, anhydrous potassium carbonate (10 eq) is added, ethylene glycol ethyl ether is added to the system, and the system is replaced with nitrogen three times. The compound of formula IV is added under nitrogen, the system is refluxed at 110°C for 24 hours under nitrogen protection, the system is cooled, filtered, washed with alcohol, and dried at 50°C for at least 10 hours. The solid obtained by concentrating the filtrate is subjected to silica gel column chromatography using dichloromethane as the solvent, and the compound of formula I is obtained.

[0050] A third object of the present application is to provide the use of the metal iridium complex in an organic electroluminescent device.

[0051] The present application provides an organic electroluminescent device comprising the metal iridium complex as described above.

[0052] Further preferably, the organic electroluminescent device comprises a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode, and the organic layer comprises the metal iridium complex of the present application.

[0053] In the present application, the organic layer comprises at least one functional layer, i.e., the metal iridium complex of the present application.

[0054] In the present application, the organic layer comprises a light-emitting layer, and the light-emitting layer comprises the metal iridium complex of the present application.

[0055] In the present application, the light-emitting layer of the organic electroluminescent device comprises a host material and a dopant material, and the dopant material is the metal iridium complex of the present application. The mixing mass ratio of the host material to the dopant material is 90:10 to 99.5:0.5, for example, 90:10, 91:9, 92:8, 93:7, 94:6, 95:5, 96:4, 97:3, 98:2, or 99:1.

[0056] In the present application, the metal iridium complex exists in the organic layer in a single form or in a mixture with other substances.

[0057] Preferably, the organic layer further comprises one or a combination of at least two of a hole injection layer, a hole transport layer, a layer having both hole injection and hole transport capabilities, an electron blocking layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a layer having both electron transport and electron injection capabilities.

[0058] Compared with the prior art, the present application has the following beneficial effects:

[0059] The present application generates metal iridium complexes by selecting specific alkyl ligand combination, changing the substituent group on the ligand, increasing branched alkyl, substituted or unsubstituted aryl and substituted or unsubstituted alkyl, improves the intermolecular spatial configuration, reduces the intermolecular bond angle, increases the lifetime, has good spatial torsion ability, thereby avoiding carrier migration, adjusts the wavelength of the metal iridium complex, has lower voltage, and significantly improves the power efficiency, has low evaporation temperature, high photoelectrochemical stability, high luminous efficiency, long device life and other advantages, and the preparation method of the metal iridium complex of the present application is simple, the product purity is high, and is suitable for industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0060] Figure 1 The nuclear magnetic resonance hydrogen spectrum of compound Z-1. DETAILED DESCRIPTION

[0061] The technical solutions of the present application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only to help understand the present application, and should not be regarded as specific limitations of the present application.

[0062] In addition, it should be noted that the values given in the following examples are as accurate as possible, but those skilled in the art understand that due to unavoidable measurement errors and experimental operation problems, each number should be understood as an approximate number, rather than an absolutely accurate number.

[0063] Example 1

[0064]

[0065] Under nitrogen protection, 3,6-dibromo-2-methyl aniline (1 eq, CAS: 1263376-95-9), K3PO4·3H2O (3 eq) were put into the reaction system, 1.4-dioxane was added, DBA palladium (tris(dibenzylideneacetone)dipalladium, 0.01 eq), S-Phos (2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl, 0.1 eq) were added under nitrogen protection, pinacol diboronic acid (1 eq, CAS: 73183-34-3) was added in three batches every 1 hour, after addition, it was refluxed at 100°C under nitrogen protection for 24 hours, then cooled to 25°C, concentrated under reduced pressure, the crude product was column chromatographed (200-300 mesh, 500 g) to remove impurities, the developing agent was EA (ethyl acetate): PE (petroleum ether) = 1:15 by volume, the receiving liquid was spun to no liquid flow, vacuum dried to obtain the compound intermediate 1, the yield was 66.7%.

[0066]

[0067] Under nitrogen protection, intermediate 1 (1 eq), anhydrous potassium carbonate (3 eq) were put into the reaction system, toluene, anhydrous ethanol, pure water were added, Pd(PPh3)4 (tetra(triphenylphosphine)palladium, 0.015 eq) was added under nitrogen protection, 5-bromo-4-chloro-6-(methylthio)pyrimidine (1 eq, CAS: 1289199-12-7) was added in three batches every 1 hour, after addition, it was refluxed at 70°C under nitrogen protection for 24 hours, then cooled to 25°C, after the reaction was cooled, ethyl acetate was extracted, washed with saturated brine three times, dried with anhydrous magnesium sulfate, concentrated under reduced pressure, the crude product was column chromatographed (200-300 mesh, 500 g) to remove impurities, the developing agent was EA: PE = 1:10 by volume, the receiving liquid was spun to no liquid flow, vacuum dried to obtain the compound intermediate 2, the yield was 57.7%.

[0068]

[0069] Under nitrogen protection, intermediate 2 (1 eq) was taken, tetrahydrofuran and glacial acetic acid were added, stirred at -10°C for 10 minutes, tert-butyl nitrite was added under nitrogen protection, reacted at -10°C for 2 hours, then the reaction was restored to room temperature for 2 hours, after the reaction was completed, it was diluted with water, the crude product was column chromatographed (200-300 mesh, 500 g) to remove impurities, the developing agent was EA: PE = 1:10 by volume, the receiving liquid was spun to no liquid flow, vacuum dried to obtain the compound intermediate 3, the yield was 55.6%.

[0070]

[0071] Under the protection of nitrogen, intermediate 3 (1 eq), anhydrous potassium carbonate (3 eq) were put into the reaction system, toluene, anhydrous ethanol, pure water were added, Pd(PPh3)4 (0.015 eq) was added under the protection of nitrogen, (4-tert-butyl-naphthalen-2-yl)boronic acid (1 eq, CAS: 2387377-70-8) was added in three batches at an interval of 1 hour, after addition, 100 ℃ was refluxed under the protection of nitrogen for 24 h, and then cooled to 25 ℃. After the reaction was cooled, ethyl acetate was extracted, saturated brine was washed three times, anhydrous magnesium sulfate was dried, and concentrated under reduced pressure. The crude product was column chromatographed (200-300 mesh, 500 g) to remove impurities, the developing agent was EA:PE (volume ratio) = 1:10, the receiving liquid was spun to no liquid flow, vacuum drying, to obtain compound formula II-1, the yield was 91.2%.

[0072]

[0073] Under the protection of nitrogen, intermediate 4 (1 eq), anhydrous potassium carbonate (3 eq) were put into the reaction system, toluene, anhydrous ethanol, pure water were added, Pd(PPh3)4 (0.015 eq) was added under the protection of nitrogen, (4-tert-butyl-naphthalen-2-yl)boronic acid (1 eq, CAS: 2387377-70-8) was added in three batches at an interval of 1 hour, after addition, 100 ℃ was refluxed under the protection of nitrogen for 24 h, and then cooled to 25 ℃. After the reaction was cooled, ethyl acetate was extracted, saturated brine was washed three times, anhydrous magnesium sulfate was dried, and concentrated under reduced pressure. The crude product was column chromatographed (200-300 mesh, 500 g) to remove impurities, the developing agent was EA:PE (volume ratio) = 1:10, the receiving liquid was spun to no liquid flow, vacuum drying, to obtain compound formula II-1, the yield was 91.2%.

[0074]

[0075] Under the protection of nitrogen, ligand II-1 (2.5 eq), IrCl3·3H2O (1 eq) were put into the reaction system, a mixed solution of ethylene glycol ether and pure water was added, 110 ℃ was refluxed under the protection of nitrogen for 24 h, and then cooled to room temperature. A precipitate was precipitated, the precipitate was suction filtered, washed with water, anhydrous ethanol and petroleum ether in sequence, and dried at 50 ℃ for at least 10 h, to obtain bridged ligand formula III-1, the yield was 53%.

[0076]

[0077] Under the protection of nitrogen system, the ligand formula III-1 (1 eq) was taken, anhydrous potassium carbonate (10 eq) was added, and ethylene glycol ether was added to replace nitrogen three times, 3,7-diethyl non-4,6-diketone (CAS: 872802-98-7, 2.5 eq) was added under nitrogen, and the system was refluxed at 110°C for 24h under nitrogen protection. After cooling, filtration, alcohol washing, and drying at 50°C for at least 10h, the solid was obtained by concentrating the filtrate with dichloromethane as the solvent and silica gel column chromatography. The final compound Z-1 (11.78g, yield 59.6%) was obtained.

[0078] HPLC purity: more than 99.5%;

[0079] MS (ESI, m / Z): [M+H]+: 1306.69.

[0080] The nuclear magnetic resonance spectrum of compound Z-1 is shown in Figure 1

[0081] Example 2

[0082]

[0083] Under the protection of nitrogen, intermediate 4 (1 eq) and anhydrous potassium carbonate (3 eq) were placed in the reaction system, toluene, anhydrous ethanol, and pure water were added, and Pd(PPh3)4 (0.015 eq) was added under nitrogen protection. (4-Chloronaphthalen-2-yl)boronic acid (1 eq, CAS: 2575133-50-3) was added in three batches at an interval of 1h. After addition, it was refluxed at 100°C for 24h under nitrogen protection, and then cooled to 25°C. After cooling, ethyl acetate was extracted, washed with saturated brine three times, dried with anhydrous magnesium sulfate, concentrated under reduced pressure, and column chromatography (200-300 mesh, 500g) was performed on the crude product to remove impurities. The developing agent was EA:PE (volume ratio) = 1:50. The receiving liquid was spun until no liquid flowed out, and vacuum drying was performed to obtain the compound intermediate 5 with a yield of 89.8%.

[0084]

[0085] ​Under the protection of nitrogen, intermediate 5 (1 eq), anhydrous potassium carbonate (3 eq) were put into the reaction system, toluene, anhydrous ethanol, pure water were added, Pd(PPh3)4 (0.015 eq) was added under the protection of nitrogen, t-butyl boronic acid (1 eq, CAS: 86253-12-5) was added in three batches at an interval of 1 hour, after addition, it was refluxed at 100 ℃ for 24 h under the protection of nitrogen, and then cooled to 25 ℃. After the reaction was cooled, ethyl acetate was extracted, saturated brine was washed for three times, anhydrous magnesium sulfate was dried, and concentrated under reduced pressure. The crude product was column chromatographed (200-300 mesh, 500 g) to remove impurities, and the developing agent was EA:PE (volume ratio) = 1:50. The receiving liquid was spun to no liquid flow, and vacuum drying was performed to obtain the compound shown in formula II-1, and the yield was 89.6%.

[0086]

[0087] Under the protection of nitrogen, ligand II-88 (2.5 eq) and IrCl3·3H2O (1 eq) were put into the reaction system, a mixed solution of ethylene glycol ether and pure water was added, and the mixture was refluxed at 110 ℃ for 24 h under the protection of nitrogen, and then cooled to room temperature. A precipitate was precipitated, the precipitate was suction filtered, and washed with water, anhydrous ethanol and petroleum ether in sequence, and dried at 50 ℃ for at least 10 h to obtain the bridged ligand of formula III-88, and the yield was 52%.

[0088]

[0089] Under the protection of nitrogen, ligand III-88 (1 eq) and anhydrous potassium carbonate (10 eq) were put into the reaction system, ethylene glycol ether was added, and the system was replaced with nitrogen for three times. 3,7-diethyl non-4,6-dione (CAS: 872802-98-7, 2.5 eq) was added under the protection of nitrogen, and the mixture was refluxed at 110 ℃ for 24 h under the protection of nitrogen. After cooling, suction filtration, alcohol washing and drying at 50 ℃ for at least 10 h, dichloromethane was used as a solvent, and column chromatography was performed on silica gel. The filtrate was concentrated, and a solid was precipitated to obtain the final compound Z-1 (13.68 g, yield 52.3%).

[0090] HPLC purity: greater than 99.5%;

[0091] MS (ESI, m / Z): [M+H]+: 1334.75.

[0092] In the embodiments of the present application, the preparation methods of other metal iridium complexes shown in formulas Z-1 to Z-1062 are basically the same as those in the above-mentioned embodiments, and only the corresponding raw materials need to be replaced. Herein, no further description is given.

[0093] Device embodiment 1

[0094] An organic electroluminescent device was prepared using the metal iridium complex Z-1 prepared in Example 1, according to the following procedure:

[0095] An ITO glass substrate having a coating thickness of 1500 A was washed in distilled water three times, ultrasonically washed for 30 minutes, and repeatedly washed in distilled water three times, ultrasonically washed for 30 minutes. After the distilled water washing was completed, the substrate was ultrasonically washed in isopropyl alcohol, acetone, and methanol, dried, and transferred to a plasma cleaner. The ITO glass substrate was washed in the plasma cleaner for 5 minutes and then introduced into an evaporation machine. Under vacuum conditions, the standard pressure was set to 1 x 10 -6 torr, and an organic layer was formed on the ITO glass substrate in the order of CuPc (200 A), NPB (400 A), CBP + metal iridium complex Z-1 (200 A), Alq3 (300 A), LiF (5 A), and Al (1000 A).

[0096] wherein CBP + metal iridium complex Z-1 means that the metal iridium complex Z-1 is doped in CBP at a concentration of 5% by mass.

[0097] The structures of CuPc, NPB, CBP, and Alq3 used in the device examples are as follows:

[0098]

[0099] Device Example 2 - Device Example 50

[0100] The procedure of Device Example 1 was followed, except that the doped material compound Z-1 was replaced by Z-8, Z-18, Z-22, Z-57, Z-78, Z-100, Z-144, Z-166, Z-173, Z-206, Z-255, Z-270, Z-311, Z-341, Z-356, Z-413, Z-430, Z-464, Z-480, Z-503, Z-540, Z-566, Z-579, Z-592, Z-603, Z-606, Z-622, Z-633, Z-667, Z-680, Z-693, Z-716, Z-744, Z-758, Z-786, Z-792, Z-804, Z-846, Z-866, Z-889, Z-910, Z-919, Z-930, Z-950, Z-961, Z-973, Z-988, Z-1002, Z-1032, respectively, and the organic electroluminescent device was prepared according to the same procedure of Device Example 1.

[0101] Device Comparative Example 1 - Device Comparative Example 6

[0102] The organic electroluminescent device was prepared according to the same method of device example 1, except that (btp)2Ir(acac), comparative example 2, comparative example 3, comparative example 4, comparative example 5, comparative example 6 compound respectively instead of doped compound Z-1 in example 1, the specific structure is as follows:

[0103]

[0104] The driving voltage, luminous efficiency and lifetime of the organic electroluminescent device obtained by the above device example and device comparative example were characterized at a brightness of 8000 (nits), and the test results are shown in Table 1.

[0105] It should be noted that the relative value is the comparison result between numbers, and the relative value is usually expressed in percentage or decimal form to indicate the degree of change of a number relative to other numbers. In addition, in the industrial field, the relative value can also be used to measure the degree of change in production efficiency, and to evaluate the quality and stability of products, etc.

[0106] Table 1 performance test results

[0107]

[0108]

[0109] As shown in Table 1, under the same current conditions, the organic electroluminescent device prepared by the metal iridium complex in the application can adjust the wavelength of the metal iridium complex by selecting a specific alkyl ligand, changing the combination of substituents on the ligand, increasing the branched alkyl group, substituted or unsubstituted aryl group and substituted or unsubstituted alkyl group, and has a better space twisting ability, thereby avoiding carrier migration. When it is used as a specific doping material of the light-emitting layer and applied to the organic electroluminescent device, it has a lower voltage, and the power efficiency is significantly improved, has a low evaporation temperature, high photoelectrochemical stability, high luminous efficiency, long device life and other advantages. The preparation method provided by the application has simple process, high purity of the prepared product, and is suitable for industrial production.

[0110] The applicant declares that the metal iridium complex of the application and its preparation method and the organic electroluminescent device are illustrated by the above examples, but the application is not limited to the above examples, that is, it does not mean that the application must rely on the above examples to be implemented. Those skilled in the art should understand that any improvement of the application, equivalent replacement of the selected raw materials of the application, addition of auxiliary ingredients, selection of specific methods, etc. fall within the scope of protection and disclosure of the application.

Claims

1. A metal iridium complex characterized in that, The structure of the metal iridium complex is specifically shown in Formula I: ； wherein X is independently selected from O, S, Se, NRx, CRxRy, SiRxRy, or GeRxRy, and Rxand Ryare each independently selected from hydrogen, methyl, -F, -D, -CN, -CD3, or phenyl; R1, R2, R3, R4, and R5are each independently selected from hydrogen, deuterium, halogen, -CN, substituted or unsubstituted C1-C20alkyl, substituted or unsubstituted C3-C20cycloalkyl, substituted or unsubstituted phenyl, trimethylgermanium, or trimethylsilicon; each Ra is independently selected from hydrogen, -D, -CN, -F, substituted or unsubstituted C1-C20alkyl, substituted or unsubstituted phenyl, substituted or unsubstituted C3-C10cycloalkyl, and Ra is mono- or polysubstituted; ring A is independently selected from absent, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl; R6, R7, and R8are each independently selected from hydrogen, -D, -CN, -F, substituted or unsubstituted C1-C20alkyl, substituted or unsubstituted C3-C10cycloalkyl; the substituents in the substituted groups are selected from -D, C1-C6alkyl, -F, -CN, trimethylgermyl, trimethylsilyl, or C3-C10cycloalkyl; the hydrogen atoms in Formula I are unsubstituted by deuterium, partially substituted by deuterium, or fully substituted by deuterium.

2. The metal iridium complex of claim 1, wherein X is independently selected from O, S, Se, NRx, CRxRy, SiRxRy, or GeRxRy, and Rxand Ryare each independently selected from hydrogen, methyl; R1, R2, R3, R4, and R5are each independently selected from hydrogen, -F, -CD3, -D, -CN, substituted or unsubstituted phenyl, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted butyl, substituted or unsubstituted pentyl, substituted or unsubstituted cyclopentyl, trimethylsilicon, or trimethylgermanium; each Ra is independently selected from -F, -CD3, -D, -CN, substituted or unsubstituted phenyl, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted butyl, substituted or unsubstituted pentyl, substituted or unsubstituted cyclopentyl.

3. The metal iridium complex of claim 1, wherein selected from the group consisting of: ； ； ； ； ； ； ； 。 4. The metal iridium complex of claim 1, wherein R6, R7, and R8are each independently selected from hydrogen, -F, -D, -CN, substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted butyl, substituted or unsubstituted pentyl, substituted or unsubstituted cyclopropyl, substituted or unsubstituted cyclopentyl; wherein the substituted methyl is -CD3, CF3, or CD2F.

5. The metal iridium complex of claim 1, wherein is selected from any one of the following structures: ； ； wherein D represents deuterium.

6. A metal iridium complex characterized in that, the metal iridium complex is selected from any one of the following structures: ； wherein D represents deuterium.

7. An organic electroluminescent device, characterized by comprising the organic electroluminescence device comprises the metal iridium complex of any one of claims 1-6. the organic electroluminescence device comprises the metal iridium complex of any one of claims 1-6.

8. The organic electroluminescent device according to claim 7, characterized in that The organic electroluminescent device comprises a first electrode, a second electrode and an organic layer disposed between the first electrode and the second electrode, the organic layer comprising a light-emitting layer, the light-emitting layer comprising a host material and a dopant material, the dopant material being the metal iridium complex according to any one of claims 1-6.

9. The organic electroluminescent device according to claim 8, characterized in that The mass ratio of the host material to the dopant material is 90:10-99.5:0.

5.

10. The organic electroluminescent device according to claim 8, characterized in that, The organic layer further comprises one or a combination of at least two of a hole injection layer, a hole transport layer, a layer having both hole injection and hole transport capabilities, an electron blocking layer, a hole blocking layer, an electron transport layer, an electron injection layer and a layer having both electron transport and electron injection capabilities.

Images