Phosphorescent material and use thereof

Abstract

The application discloses a phosphorescent material and application thereof, and a structural general formula of the phosphorescent material is shown in the figure. The phosphorescent material provided by the application is combined by selecting specific heterocyclic ligands, wavelength of the compound is adjusted, and the obtained organic metal compound is used in an organic electroluminescent device, so that the luminous efficiency of the organic electroluminescent device is improved, and the service life is long.

Description

Technical Field

[0001] This invention relates to the field of organic optoelectronic materials technology, and more specifically to a heterocyclic structure multi-nitrogen atom-based metal iridium complex phosphorescent material and its applications. Background Technology

[0002] Organic light-emitting diodes (OLEDs) have garnered significant attention in the fields of next-generation large-area flat panel displays and semiconductor solid-state lighting sources due to their advantages such as self-emission, fast response, high brightness, and flexibility. Their potential for superior performance in display technology makes them the most competitive technology in the third-generation flat panel market. Compared to traditional CRT, LCD, and PDP display devices, OLEDs combine all the advantages of existing displays while possessing their own unique strengths. They offer high brightness, high contrast, high definition, wide viewing angle, and wide color gamut for high-quality images, while also being ultra-thin, ultra-light, low-driving-voltage, low-power, and wide-temperature-range to meet the portability, energy efficiency, and outdoor operation requirements of portable devices. Furthermore, self-emission, high luminous efficiency, short response time, transparency, and flexibility are unique characteristics of OLED displays. Therefore, OLEDs have excellent development prospects.

[0003] Organic light-emitting diodes (OLEDs) primarily use phosphorescent materials as their luminescent agents. The independent emission of the three primary colors—red, blue, and green—is currently the most widely used color mode, and the key technological focus is on improving the purity and efficiency of the luminescent materials. Therefore, in recent years, research has been concentrated on phosphorescent materials, with iridium complexes being the most prevalent. However, limitations in materials have significantly hampered the development of organic light-emitting devices. Further improvements are still needed in terms of lifespan and production costs.

[0004] As luminescent materials, excitons are formed by the recombination of electrons and holes injected from each electrode. Singlet excitons emit fluorescence, while triplet excitons emit phosphorescence. Singlet excitons have a 25% formation probability, while phosphorescent triplet excitons have a 75% formation probability. Therefore, triplet excitons offer greater luminescent efficiency compared to singlet excitons. Among such phosphorescent materials, red phosphorescent materials can exhibit greater luminescent efficiency than fluorescent materials. Therefore, red phosphorescent materials are being extensively studied as an important factor in improving the efficiency of organic electroluminescent devices.

[0005] However, currently available luminescent materials suffer from drawbacks such as high synthesis costs, demanding synthesis processes, high purification requirements, short lifespans, and low efficiency. Therefore, developing a material with high luminescent efficiency and long lifespan is a pressing technical challenge. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a phosphorescent material, its preparation method and application. The phosphorescent material provided by this invention, as a light-emitting material for organic electroluminescent devices, can improve the luminous efficiency of the devices and extend their service life.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A phosphorescent material, characterized in that the structure of the phosphorescent material is as shown in Formula I:

[0009]

[0010] in:

[0011] R1 through R6 each independently represent hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, amino, sulfonic acid, sulfonyl, phosphoryl, or substituted or unsubstituted C1-C atoms. 60 Alkyl, substituted or unsubstituted C6-C 60 Aryl, substituted or unsubstituted C3-C 60 Cycloalkyl, substituted or unsubstituted C1-C 60 Alkoxy, substituted or unsubstituted C1-C 60 Alkylamine group, substituted or unsubstituted C2-C 60 olefinic group, substituted or unsubstituted C2-C 60 Alkyne group, substituted or unsubstituted C4-C 60 Heterocyclic group, substituted or unsubstituted C8-C 60 Fused ring group, substituted or unsubstituted C5-C 60 Spirocyclic groups, R1 to R6 may be the same or different;

[0012] The positions of R1 to R6 are arbitrary positions within the ring, the number of substituents in R1 to R4 is 0 to 4, the number of substituents in R5 is 0 to 1, and the number of substituents in R6 is 0 to 2.

[0013] Preferably, R1 to R6 each independently represent hydrogen, deuterium, substituted or unsubstituted C1-C atoms. 20 Alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl, substituted or unsubstituted C3-C 20 Alkoxy, substituted or unsubstituted C4-C 20 Heterocyclic groups, substituted or unsubstituted C6-C 20 aryl, substituted or unsubstituted C 10 -C 20 Fused ring groups, where R1 to R6 may be the same or different.

[0014] Preferably, the substituted or unsubstituted C1-C 20Alkyl groups include any one of methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, and 2-methylpentyl.

[0015] Preferably, the substituted or unsubstituted C6-C 20 Aryl groups include any one of benzene, biphenyl, terphenyl, naphthalene, anthracene, phenanthrene, pyrene, and fluorene.

[0016] Preferably, the substituted or unsubstituted C3-C 20 Cycloalkyl groups include any one of cyclopropyl, cyclopentyl, cyclohexyl, and adamantaneamino.

[0017] Preferably, the substituted or unsubstituted C4-C 20 Heterocyclic groups include aromatic or non-aromatic cyclic groups containing at least one heteroatom selected from one or more combinations of O, S, N, P, B, Si, and Se.

[0018] Preferably, each of R1 to R6 independently forms a fused ring / aromatic heterocycle with its respective ring, and the substituents that do not form a fused ring or aromatic heterocycle represent hydrogen, deuterium, substituted or unsubstituted C3-C atoms. 60 Alkyl, substituted or unsubstituted C6-C 60 Aryl, substituted or unsubstituted C3-C 20 cycloalkyl, substituted or unsubstituted C4-C 60 Heterocyclic groups, substituted or unsubstituted C 10 -C 20 Fused ring groups, substituted or unsubstituted C5-C 60 Spirocyclic group.

[0019] Preferably, each of R1 to R6 independently forms a fused ring / aromatic heterocycle with other adjacent substituents on its respective ring, and the substituents that do not form a fused ring or aromatic heterocycle represent hydrogen, deuterium, substituted or unsubstituted C3-C atoms. 60 Alkyl, substituted or unsubstituted C6-C 60 Aryl, substituted or unsubstituted C3-C 20 cycloalkyl, substituted or unsubstituted C4-C 60 Heterocyclic groups, substituted or unsubstituted C 10 -C 20 Fused ring groups, substituted or unsubstituted C5-C 60 Spirocyclic group.

[0020] Preferably, the hydrogen atoms in the groups or substituents of R1 to R6 are deuterated.

[0021] Preferably, the specific structural formula of the phosphorescent material is as follows:

[0022]

[0023]

[0024] .

[0025] The present invention also provides a method for preparing the above-mentioned phosphorescent material, comprising the following steps:

[0026] S1. Under the protection of an inert gas, the compound of formula II is reacted with iridium trichloride. After the reaction is completed, the compound of formula III is obtained by post-treatment.

[0027] S2. Under inert gas protection, the compound of formula III is reacted with silver trifluoromethanesulfonate and methanol. After the reaction is completed, the compound of formula IV is obtained by post-treatment.

[0028] S3. Under inert gas protection and at a temperature of 85-95℃, the compound of formula IV and the compound of formula V are refluxed in anhydrous ethanol for 20-30 h. After the reaction is completed, the compound with the formula I structure is obtained by post-treatment.

[0029] Its synthetic route is as follows:

[0030] .

[0031] Preferably, in step S1, the molar ratio of the compound of formula II to iridium trichloride is (2.2-3):1.

[0032] Furthermore, in step S1, the compound of formula II is dissolved in a mixed solvent of ethylene glycol ethyl ether and water, wherein the volume ratio of ethylene glycol ethyl ether to water is (2~5):1, the reaction temperature is 115-125℃, and the reaction time is 20-30 hours.

[0033] Furthermore, in step S1, the post-processing is as follows: after the reaction is completed, the mixture is cooled to room temperature, and a precipitate is formed. The precipitate is filtered, washed with water, anhydrous ethanol, and petroleum ether in sequence, and dried to obtain a yellow powder of the bridged ligand III compound.

[0034] Preferably, in step S2, the molar ratio of the compound of formula III to silver trifluoromethanesulfonate is 1:(2.2-3.5).

[0035] Furthermore, in step S2, the compound of formula III reacts with silver trifluoromethanesulfonate and methanol in dichloromethane, wherein the volume ratio of methanol to dichloromethane is 1:(2~5), the reaction temperature is 20-30℃, and the reaction time is 24-48 hours.

[0036] Furthermore, in step S2, the post-processing procedure is as follows: the reaction solution is cooled to room temperature, and the column chromatography (short column) filtrate is concentrated until a solid precipitates out, yielding a yellow powder of the iridium complex intermediate of formula IV.

[0037] Preferably, in step S3, the reaction molar ratio of the compound of formula IV to the compound of formula V is 1:(1.5-3.5).

[0038] Furthermore, in step S3, the post-processing procedure is as follows: filtration, alcohol washing, drying, silica gel column chromatography using dichloromethane as solvent, concentration of the filtrate to precipitate the solid, and finally obtaining the target compound of the yellow compound formula I.

[0039] The present invention also provides an application of the above-mentioned phosphorescent material in the preparation of organic electroluminescent devices.

[0040] The present invention also provides an organic electroluminescent device, comprising a substrate, and an anode layer, a hole transport layer, an organic light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer and a cathode layer sequentially deposited on the substrate, wherein the organic light-emitting layer comprises a host material and a dopant material, and the dopant material is the aforementioned phosphorescent material.

[0041] Preferably, the weight ratio of the host material to the dopant material is 90:10 to 99.5:0.5.

[0042] Preferably, the thickness of the organic light-emitting layer is 25-35 nm.

[0043] The present invention further provides the application of the above-mentioned organic electroluminescent device in organic light-emitting devices, organic solar cells, electronic paper, organic photoreceptors or organic thin film transistors.

[0044] As can be seen from the above technical solution, compared with the prior art, the present invention provides a phosphorescent material, its preparation method and application, which has the following beneficial effects:

[0045] (1) The phosphorescent material provided by the present invention, by selecting specific heterocyclic complexes and adjusting the wavelength of the compound, the resulting organometallic compound, when used in organic electroluminescent devices, improves the luminous efficiency of the device and has a long service life.

[0046] (2) The preparation method of phosphorescent material provided by the present invention is simple and efficient, and the prepared product has high purity. Detailed Implementation

[0047] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] Example 1

[0049] The specific steps for synthesizing Formula I-1 are as follows:

[0050]

[0051] S1. Under nitrogen protection, weigh out 50 mmol (7.75 g) of formula II-1 and 20 mmol (7.05 g) of IrCl3·3H2O and add them to the reaction system. Add 210 mL of a mixed solution of ethylene glycol ethyl ether and 70 mL of purified water. Reflux under nitrogen protection for 24 hours and then cool to room temperature. A precipitate will form. Filter the precipitate and wash it with water, anhydrous ethanol and petroleum ether in sequence and dry it to obtain a yellow powder of bridged ligand formula III-1 (5.36 g, yield 50%).

[0052] S2. Weigh intermediate formula III-1 (5 mmol, 5.36 g), add silver trifluoromethanesulfonate (15 mmol, 3.86 g), then add 100 ml of dichloromethane and 40 ml of methanol to the system. Under nitrogen protection, reflux for 24 hours, cool to room temperature, and concentrate the filtrate by column chromatography (short column) until a solid precipitates to obtain yellow powder iridium complex intermediate formula IV-1 (6.55 g, yield 92%).

[0053] S3. Weigh intermediate formula IV-1 (9 mmol, 6.41 g), add ligand formula V-1 (27 mmol, 7.99 g), and then add 120 ml of anhydrous ethanol to the system. Under nitrogen protection, reflux for 24 hours, filter, wash with ethanol, and dry. Use dichloromethane as solvent and perform silica gel column chromatography. Concentrate the filtrate to precipitate the solid, giving the final yellow compound formula I-1. Its HPLC purity is greater than 99%. The mass spectrometry and elemental analysis results of compound formula I-1 are as follows:

[0054] Mass spectrometry: Calculated value 796.18; Measured value 796.13;

[0055] Elemental analysis: Calculated values: C: 63.38; H: 3.42; Ir: 24.15; N: 7.04; O: 2.01; Test values: C: 63.39; H: 3.43; Ir: 24.14; N: 7.02; O: 2.02.

[0056] Example 2

[0057] The specific steps for the synthesis of I-32 are as follows:

[0058]

[0059] S1. Under nitrogen protection, weigh out formula II-32 (48 mmol, 8.79 g) and IrC13·3H2O (20 mmol, 7.05 g) and add them to the reaction system. Add a mixed solution of 300 mL ethylene glycol ethyl ether and 100 mL purified water. Reflux under nitrogen protection for 24 hours, then cool to room temperature. A precipitate will form. Filter the precipitate, wash it with water, anhydrous ethanol and petroleum ether in sequence and dry it to obtain a yellow powder of bridged ligand formula III-32 (5.68 g, yield 48%).

[0060] S2. Weigh intermediate formula III-32 (4.5 mmol, 5.33 g), add silver trifluoromethanesulfonate (14 mmol, 3.6 g), then add 100 ml of dichloromethane and 40 ml of methanol to the system. Under nitrogen protection, reflux for 24 hours, cool to room temperature, and concentrate the filtrate by column chromatography (short column) until a solid precipitates to obtain yellow powder of iridium complex intermediate formula IV-32 (6.36 g, yield 92%).

[0061] S3. Weigh intermediate formula IV-32 (8 mmol, 6.15 g), add ligand formula V-32 (24 mmol, 7.44 g), and then add 120 ml of anhydrous ethanol to the system. Under nitrogen protection, reflux for 24 hours, filter, wash with ethanol, and dry. Use dichloromethane as solvent and perform silica gel column chromatography. Concentrate the filtrate to precipitate the solid, giving the final yellow compound formula I-32 (1.73 g, yield 25%) with an HPLC purity greater than 99%. The mass spectrometry and elemental analysis results of compound formula I-32 are as follows:

[0062] Mass spectrometry: Calculated value 866.26; Measured value 866.22;

[0063] Elemental analysis: Calculated values: C: 65.18; H: 4.31; Ir: 22.19; N: 6.47; O: 1.85; Test values: C: 65.19; H: 4.30; Ir: 22.18; N: 6.46; O: 1.87.

[0064] Example 3

[0065] The specific steps for synthesizing Formula I-76 are as follows:

[0066]

[0067] S1. Under nitrogen protection, weigh 60 mmol (10.15 g) of formula II-76 and 20 mmol (7.05 g) of IrCl3·3H2O into the reaction system, add a mixed solution of 300 ml of ethylene glycol ethyl ether and 100 ml of pure water, reflux under nitrogen protection for 24 hours, and then cool to room temperature. A precipitate will form. Filter the precipitate, wash it with water, anhydrous ethanol and petroleum ether in sequence and dry it to obtain a yellow powder of bridged ligand formula III-76 (5.64 g, yield 50%).

[0068] S2. Weigh intermediate III-76 (5 mmol, 5.64 g), add silver trifluoromethanesulfonate (14 mmol, 3.6 g), then add 100 ml of dichloromethane and 40 ml of methanol to the system. Under nitrogen protection, reflux for 24 hours, cool to room temperature, and concentrate the filtrate by column chromatography (short column) until a solid precipitates. This yields a yellow powder of iridium complex intermediate IV-76 (6.66 g, 90%).

[0069] S3. Weigh intermediate formula IV-76 (9 mmol, 6.66 g), add ligand formula V-76 (22.5 mmol, 7.29 g), and then add 120 ml of anhydrous ethanol to the system. Under nitrogen protection, reflux for 24 hours, filter, wash with ethanol, and dry. Use dichloromethane and toluene as solvents for silica gel column chromatography. Concentrate the filtrate to precipitate the solid, giving the final yellow compound formula I-76 (1.76 g, yield 23%) with an HPLC purity greater than 99%. The mass spectrometry and elemental analysis results of compound formula I-76 are as follows:

[0070] Mass spectrometry: calculated value 852.24; measured value 852.28;

[0071] Elemental analysis: Calculated values: C: 64.85; H: 4.14; Ir: 22.56; N: 6.58; O: 1.88; Test values: C: 64.87; H: 4.15; Ir: 22.55; N: 6.57; O: 1.87.

[0072] Example 4

[0073] The specific steps for synthesizing Formula I-110 are as follows:

[0074]

[0075] S1. Under nitrogen protection, weigh out 50 mmol (10.56 g) of formula II-110 and 20 mmol (7.05 g) of IrCl3·3H2O and add them to the reaction system. Add a mixed solution of 300 ml of ethylene glycol ethyl ether and 100 ml of purified water. Reflux under nitrogen protection for 24 hours, then cool to room temperature. A precipitate forms. Filter the precipitate, wash it sequentially with water, anhydrous ethanol, and petroleum ether, and dry it. Obtain the yellow powder of the bridged ligand formula III-110 (6.48 g, yield 50%).

[0076] S2. Weigh intermediate III-110 (5 mmol, 6.48 g), add silver trifluoromethanesulfonate (15 mmol, 3.86 g), then add 100 ml of dichloromethane and 40 ml of methanol to the system. Under nitrogen protection, reflux for 24 hours, cool to room temperature, and concentrate the filtrate by column chromatography (short column) until a solid precipitates. This yields a yellow powder of iridium complex intermediate IV-110 (7.66 g, 93% yield).

[0077] S3. Weigh intermediate formula IV-110 (9 mmol, 6 g), add ligand formula V-110 (27 mmol, 9.13 g), and then add 120 ml of anhydrous ethanol to the system. Under nitrogen protection, reflux for 24 hours, filter, wash with alcohol, and dry. Use toluene as solvent and perform silica gel column chromatography. Concentrate the filtrate to precipitate the solid, giving the final yellow compound formula I-110 (1.88 g, yield 22%) with an HPLC purity greater than 99%. The mass spectrometry and elemental analysis results of compound formula I-110 are as follows:

[0078] Mass spectrometry: calculated value 950.35; measured value 950.3;

[0079] Elemental analysis: Calculated values: C: 66.99; H: 5.20; Ir: 20.23; N: 5.90; O: 1.68; Test values: C: 66.98; H: 5.21; Ir: 20.23; N: 5.91; O: 1.67.

[0080] Example 5

[0081] The specific steps for synthesizing Formula I-140 are as follows:

[0082]

[0083] S1. Under nitrogen protection, weigh 60 mmol (10.32 g) of formula II-140 and 20 mmol (7.05 g) of IrCl3·3H2O into the reaction system. Add a mixed solution of 300 mL of ethylene glycol ethyl ether and 100 mL of purified water. Reflux under nitrogen protection for 24 hours, then cool to room temperature. A precipitate forms. Filter the precipitate, wash it sequentially with water, anhydrous ethanol, and petroleum ether, and dry it. Obtain the yellow powder of the bridged ligand formula III-140 (5.89 g, yield 50%).

[0084] S2. Weigh intermediate III-140 (5 mmol, 5.89 g), add silver trifluoromethanesulfonate (15 mmol, 3.86 g), then add 100 mL of dichloromethane and 40 mL of methanol to the system. Under nitrogen protection, reflux for 24 hours, cool to room temperature, and concentrate the filtrate by column chromatography (short column) until a solid precipitates. A yellow powder of iridium complex intermediate IV-140 (6.78 g, 91% yield) is obtained.

[0085] S3. Weigh intermediate formula IV-140 (9 mmol, 6.72 g), add ligand formula V-140 (27 mmol, 9.45 g), and then add 120 ml of anhydrous ethanol to the system. Under nitrogen protection, reflux for 24 hours, filter, wash with ethanol, and dry. Use dichloromethane as solvent and perform silica gel column chromatography. Concentrate the filtrate to precipitate the solid, giving the final yellow compound formula I-140 (1.59 g, yield 20%) with an HPLC purity greater than 99%. The mass spectrometry and elemental analysis results of compound formula I-140 are as follows:

[0086] Mass spectrometry: calculated value 886.30; measured value 886.39;

[0087] Elemental analysis: Calculated values: C: 65.06; H: 5.12; Ir: 21.69; N: 6.32; O: 1.81; Test values: C: 65.04; H: 5.10; Ir: 21.69; N: 6.35; O: 1.82.

[0088] Example 6

[0089] The specific steps for synthesizing Formula I-176 are as follows:

[0090]

[0091] S1. Under nitrogen protection, weigh 60 mmol (11.35 g) of formula II-176 and 20 mmol (7.05 g) of IrCl3·3H2O into the reaction system. Add a mixed solution of 300 ml of ethylene glycol ethyl ether and 100 ml of purified water. Reflux under nitrogen protection for 24 hours, then cool to room temperature. A precipitate forms. Filter the precipitate, wash with water, anhydrous ethanol, and petroleum ether sequentially, and dry. Obtain the yellow powder of the bridged ligand formula III-176 (6.04 g, yield 50%).

[0092] S2. Weigh intermediate III-176 (5 mmol, 6.04 g), add silver trifluoromethanesulfonate (15 mmol, 3.86 g), then add 100 ml of dichloromethane and 40 ml of methanol to the system. Under nitrogen protection, reflux for 24 hours, cool to room temperature, and concentrate the filtrate by column chromatography (short column) until a solid precipitates. This yields a yellow powder of iridium complex intermediate IV-176 (7.41 g, 95% yield).

[0093] S3. Weigh intermediate formula IV-176 (9.5 mmol, 7.41 g), add ligand formula V-176 (28.5 mmol, 9.41 g), and then add 120 ml of anhydrous ethanol to the system. Under nitrogen protection, reflux for 24 hours, filter, wash with ethanol, and dry. Use dichloromethane as solvent and perform silica gel column chromatography. Concentrate the filtrate to precipitate the solid, giving the final yellow compound formula I-176 (2.3 g, yield 27%) with an HPLC purity greater than 99%. The mass spectrometry and elemental analysis results of compound formula I-176 are as follows:

[0094] Mass spectrometry: calculated value 898.39; measured value 898.33;

[0095] Elemental analysis: Calculated values: C: 64.19; H: 6.39; Ir: 21.40; N: 6.24; O: 1.78; Test values: C: 64.17; H: 6.37; Ir: 21.42; N: 6.25; O: 1.79.

[0096] Example 7-22

[0097] Following the synthesis method in Example 1, by simply replacing the corresponding reactants, the target compounds of Examples 7-22 can be synthesized. Their specific structures, product quality, yields, and FD-MS (mass spectrometry) results are shown in Table 1.

[0098] Table 1. Specific structures, product masses, yields, and FD-MS results of the target compounds in Examples 7-22.

[0099] Example 7 Formula I-3 <![CDATA[m / z=810.27(C 43 H 29 IrN4O=810.20)]]> 3.28 12 Example 8 Formula I-13 <![CDATA[m / z=838.20(C 45 H 33 IrN4O=838.23)]]> 3.16 11 Example 9 Formula I-27 <![CDATA[m / z=866.21(C 47 H 37 IrN4O=866.26)]]> 3.30 13 Example 10 Formula I-34 <![CDATA[m / z=962.22(C 55 H 37 IrN4O=962.26)]]> 3.28 12 Example 11 Formula I-45 <![CDATA[m / z=922.36(C 51 H 45 IrN4O=922.32)]]> 3.45 14 Example 12 Formula I-56 <![CDATA[m / z=725.62(C 37 H 31 IrN3O=725.89)]]> 3.08 9 Example 13 Formula I-62 <![CDATA[m / z=836.27(C 45 H 31 IrN4O=836.21)]]> 3.20 11 Example 14 Formula I-87 <![CDATA[m / z=894.40(C 49 H 41 IrN4O=894.29)]]> 3.12 13 Example 15 Formula I-94 <![CDATA[m / z=698.45(C 35 H 27 IrN3O=698.18)]]> 3.01 12 Example 16 Formula I-102 <![CDATA[m / z=990.26(C 57 H 41 IrN4O=990.29)]]> 3.24 13 Example 17 Formula I-117 <![CDATA[m / z=739.78(C 38 H 33 IrN3O=739.92)]]> 3.13 11 Example 18 Formula I-128 <![CDATA[m / z=920.24(C 51 H 43 IrN4O=920.31)]]> 3.30 14 Example 19 Formula I-137 <![CDATA[m / z=749.76(C 39 H 31 IrN3O=749.91)]]> 3.15 12 Example 20 Formula I-159 <![CDATA[m / z=970.37(C 55 H 45 IrN4O=970.32)]]> 3.28 14 Example 21 Formula I-161 <![CDATA[m / z=880.27(C 48 H 53 IrN3O=880.19)]]> 3.17 10 Example 22 Formula I-182 <![CDATA[m / z=782.08(C 41 H 39 IrN3O=782.00)]]> 3.11 11

[0100] Example 23

[0101] This embodiment provides an organic electroluminescent device, including a substrate, an anode layer disposed on the substrate, a hole injection layer disposed on the anode layer, a hole transport layer disposed on the hole injection layer, an organic light-emitting layer disposed on the hole transport layer, an air barrier layer disposed on the organic light-emitting layer, an electron transport layer disposed on the air barrier layer, an electron injection layer disposed on the electron transport layer, and a cathode layer disposed on the electron injection layer.

[0102] The method for preparing the organic electroluminescent device is as follows:

[0103] The ITO glass substrate with a coating thickness of 1500 Å was washed twice with distilled water, ultrasonically washed for 30 minutes, washed twice with distilled water, ultrasonically washed for 10 minutes, and after the distilled water washing was completed, it was ultrasonically washed in sequence with solvents such as isopropanol, acetone, and methanol, and then dried. It was then transferred to a plasma cleaning machine, washed for 5 minutes, and sent to a vapor deposition machine. First, N1-(2-naphthyl)-N4,N4-bis(4-(2-naphthyl(phenyl)amino)phenyl)-N1-phenylbenzene-1,4-diamine ("2-TNATA")) 60 nm is deposited on the ITO (anode). Then, NPB 60 nm is deposited, the host material 4,4'-N,N'-biphenyldicarbazole ("CBP") and the dopant compound I-1 are mixed and deposited for 30 nm, where the weight ratio of CBP to compound I-1 is 90:10. A hole blocking layer ("BAlq") 10 nm thick is deposited, an electron transport layer "Alq3" 40 nm thick is deposited, an electron injection layer LiF 0.2 nm thick is deposited, and the cathode Al is deposited for 150 nm to prepare an organic electroluminescent device.

[0104] Following the above method, replace Formula I-1 with Formula I-3, Formula I-13, Formula I-27, Formula I-32, Formula I-34, Formula I-45, Formula I-56, Formula I-62, Formula I-76, Formula I-87, Formula I-94, Formula I-102, Formula I-110, Formula I-117, Formula I-128, Formula I-137, Formula I-140, Formula I-159, Formula I-162, and Formula I-182 respectively to prepare organic electroluminescent devices of the corresponding compounds.

[0105] Comparative Example 1

[0106] An organic electroluminescent device was prepared using the same method as in Example 23, except that the dopant compound I-1 of the organic light-emitting layer was replaced with compound Ir(ppy)3. The resulting organic electroluminescent device has the following structural formula of compound Ir(ppy)3:

[0107] .

[0108] To further illustrate the luminescence performance of the novel metallic iridium complex provided by this invention as a phosphorescent material, the luminescence characteristics of the devices obtained in Example 23 and Comparative Example 1 were tested. The measurements were performed using a KEITHLEY 2400 source measurement unit and a CS-2000 spectroradiometer to evaluate the driving voltage, luminescence brightness, and luminescence efficiency. The results are shown in Table 2.

[0109] Table 2. Detection results of organic electroluminescent devices in Example 23 and Comparative Example 1

[0110] <![CDATA[Ir(ppy)3]]> 6.0 5000 23.0 56.1 Formula I-1 3.4 5000 80.3 779 Formula I-3 3.7 5000 81.9 746 Formula I-13 3.2 5000 82.0 751 Formula I-27 3.8 5000 80.7 782 Formula I-32 3.8 5000 82.8 757 Formula I-34 3.4 5000 84.1 761 Formula I-45 3.0 5000 81.2 724 Formula I-56 3.4 5000 83.0 749 Formula I-62 3.9 5000 82.9 743 Formula I-76 3.7 5000 80.1 738 Formula I-87 3.4 5000 83.7 730 Formula I-94 3.5 5000 84.1 741 Formula I-102 3.2 5000 85.1 746 Formula I-110 4.0 5000 80.5 729 Formula I-117 3.7 5000 81.7 713 Formula I-128 3.3 5000 83.9 751 Formula I-137 3.2 5000 84.9 757 Formula I-140 3.6 5000 83.1 731 Formula I-159 3.8 5000 83.4 728 Formula I-161 3.2 5000 81.9 751 Formula I-182 3.1 5000 86.1 737

[0111] As can be seen from Table 2, when the luminous intensity is 5000 cd / cm², 2 Compared with Comparative Example 1, the driving voltage of the device provided by the present invention is 3.0~4.0V, which is only about half of that of Comparative Example 1, while the efficiency (80.1~85.1) is 3~4 times that of Comparative Example 1, and the lifetime (728~782) is 13~14 times that of Comparative Example 1. It can be seen that the organic electroluminescent device prepared using the compound provided by the present invention as the light-emitting layer doping material has a significantly lower driving voltage and significantly improved luminous efficiency and lifetime compared with the organic electroluminescent device prepared using the comparative compound Ir(ppy)3 as the light-emitting layer doping material.

[0112] Those skilled in the art will readily recognize that many modifications and variations can be made to this invention without departing from its spirit and scope. Therefore, it is contemplated that this invention covers the modifications and variations provided within the scope of the appended claims and their equivalents.

[0113] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A phosphorescent material, characterized in that, The structure of the phosphorescent material is shown below: 。 2. An organic electroluminescent device, comprising a substrate, and an anode layer, a hole injection layer, a hole transport layer, an electron blocking layer, an organic light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode layer sequentially deposited on the substrate, characterized in that, The organic light-emitting layer comprises a host material and a dopant material, wherein the dopant material is the phosphorescent material as described in claim 1.

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