An organic metal iridium complex luminescent material and its application in organic electroluminescent devices

Abstract

The present invention belongs to the technical field of organic optoelectronic materials, specifically relating to an organometallic iridium complex luminescent material and its application in organic electroluminescent devices. The organometallic iridium complex luminescent material disclosed herein has a structure represented by the general formula I described in the specification. The organometallic iridium complex provided by the present invention, when used as a material in the light-emitting layer of an organic electroluminescent device, can reduce the device's driving voltage, increase the device's maximum external quantum efficiency, and extend the device's phosphorescence lifetime.

Description

Technical Field

[0001] The invention belongs to the technical field of organic photoelectric materials and relates to a novel organic metal iridium complex and a preparation method thereof and application thereof in preparing an organic electroluminescent device. Background Art

[0002] Organic electronic devices include, but are not limited to, organic light-emitting diodes (OLEDs), organic field-effect transistors (O-FETs), organic light-emitting transistors (OLETs), organic photovoltaics (OPVs), dye-sensitized solar cells (DSSCs), organic optical detectors, organic photoreceptors, organic field-effect devices (OFQDs), light-emitting electrochemical cells (LECs), organic laser diodes, and organic plasmonic light-emitting devices.

[0003] In 1987, Tang and Van Slyke of Eastman Kodak reported a double-layer organic electroluminescent device that included an arylamine hole transport layer and a tris-8-hydroxyquinoline-aluminum layer as an electron transport layer and a light-emitting layer. Once a bias voltage was applied to the device, green light was emitted from the device. This invention laid the foundation for the development of modern organic light-emitting diodes (OLEDs). The most advanced OLEDs can include multiple layers, such as charge injection and transport layers, charge and exciton blocking layers, and one or more light-emitting layers between the cathode and anode. Since OLEDs are self-luminous solid-state devices, they offer great potential for display and lighting applications. In addition, the inherent properties of organic materials, such as their flexibility, can make them very suitable for special applications, such as on flexible substrates.

[0004] The luminous color of OLED can be achieved through the structural design of the luminescent material. OLED can include one luminescent layer or multiple luminescent layers to achieve the desired spectrum. Green, yellow and red OLEDs, phosphorescent materials have been successfully commercialized. Blue phosphorescent devices still have problems such as blue unsaturation, short device life and high operating voltage. Commercial full-color OLED displays usually adopt a hybrid strategy, using blue fluorescence and phosphorescent yellow, or red and green. At present, the efficiency of phosphorescent OLEDs decreases rapidly under high brightness conditions, which is still a problem. And because the synthesis process of phosphorescent materials is relatively complex, time-consuming and has a low lifespan, in view of the current industrial application requirements of OLED devices and the optoelectronic characteristics requirements of OLED devices, it is necessary to select more suitable and high-performance luminescent layer doping materials.

[0005] Therefore, how to develop a high-performance phosphorescent material that enables organic electroluminescent devices to have comprehensive characteristics such as high efficiency, long life and low voltage is a technical problem that people in this field urgently need to solve. Summary of the Invention

[0006] In light of this, the present invention provides an organometallic iridium complex, a preparation method thereof, and its use in an organic electroluminescent device. The iridium metal complex provided by the present invention, when used as a material in the light-emitting layer of an organic electroluminescent device, can reduce the device's driving voltage, increase the device's maximum external quantum efficiency, and extend the device's phosphorescence lifetime.

[0007] In order to achieve the above objectives, the first object of the present invention is to provide an organometallic iridium complex luminescent material.

[0008] The following technical solutions are adopted:

[0009] An organometallic iridium complex material having a structure shown in general formula I:

[0010]

[0011] in,

[0012] m is 0, 1, or 2;

[0013] X1 is selected from O or S;

[0014] X2, X3, X4 and X5 are independently selected from carbon or nitrogen;

[0015] R1, R2 and R4 represent a monosubstituent, a disubstituent, a trisubstituent, a tetrasubstituent or no substituent, and R3 represents a monosubstituent, a disubstituent or no substituent; and

[0016] R1, R2, R3, and R4 are each independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 3-15 membered cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, and combinations thereof.

[0017] Furthermore, the C1 to C20 alkyl groups may all be deuterated.

[0018] Furthermore, the ligand LA is selected from any one of the following structures:

[0019]

[0020]

[0021] Furthermore, the ligand LB is selected from any one of the following structures:

[0022]

[0023] Wherein, R3 and R4 are selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted C1-C20 alkyl, and the C1-C20 alkyl may be deuterated.

[0024] Furthermore, the iridium complex luminescent material is selected from any one of the following structures I-1, I-2, I-3, I-4, I-5, and I-6:

[0025]

[0026] Among the above-mentioned structures I-1, I-2, I-3, I-4, I-5, and I-6, I-1, I-2, I-3, and I-4 are preferred. The substituent groups and the number of substituents of R1, R2, R3, and R4 in the above-mentioned structural formulas are consistent with the range defined in the general structural formula I and are not repeated here.

[0027] In the above technical solution, the iridium metal complex is most preferably selected from the following structures:

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036] Only some specific structural forms are listed above, but this series of iridium metal complexes is not limited to the above molecular structures. Other specific molecular structures can be obtained by simple transformation of some simple groups and their substituted groups and substitution positions, which will not be listed here one by one.

[0037] The second object of the present invention is to provide the use of the above-mentioned organometallic iridium complex luminescent material in an organic electroluminescent device.

[0038] An electroluminescent device comprising the iridium metal complex. The organic electroluminescent device comprises: a first electrode, a second electrode, and an organic layer disposed between the two electrodes, wherein the organic layer comprises the iridium metal complex of the present invention; the iridium metal complex is present in the organic layer in a single form or mixed with other substances.

[0039] The organic layer includes at least one or more of a hole injection layer, a hole transport layer, a layer having both hole injection and hole transport skills, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a layer having both electron transport and electron injection skills.

[0040] The organic electroluminescent device comprises at least one functional layer, namely the iridium metal complex of the present invention.

[0041] The organic electroluminescent device comprises a light-emitting layer, and the light-emitting layer contains the iridium metal complex of the present invention.

[0042] The light-emitting layer of the organic electroluminescent device comprises a host material and a doping material, wherein the doping material is the iridium metal complex of the present invention, and the mixing ratio of the host material to the doping material is 90:10 to 99.5:0.5.

[0043] The device of the present invention can be used in organic light-emitting devices, organic solar cells, electronic paper, organic photoreceptors or organic thin film transistors.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] The present invention provides an iridium metal complex. By selecting a specific heterocyclic ligand for coordination and adjusting the position of a substituent or the activity of the substituent, the wavelength of the obtained iridium metal complex undergoes a significant red shift or blue shift. When the obtained iridium metal complex is used in an organic electroluminescent device, the maximum external quantum efficiency of the device is improved, the phosphorescence lifetime is delayed, and the driving voltage is reduced. DETAILED DESCRIPTION

[0046] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0047] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0048] Example 1 Preparation of G-13

[0049]

[0050] The first step: first weigh 2,5-dibromopyridine (197.5mmol, 46.67g), (7-phenyldibenzofuran-4-alkyl) boronic acid (197.5mmol, 56.89g), anhydrous potassium carbonate (395mmol, 54.51g), toluene (920ml), ethanol (460ml), and water (920ml), replace the nitrogen, and under nitrogen protection, add (tetrakistriphenylphosphine) palladium (3.95mmol, 4.56g) to the reaction system, react at 60°C for 12 hours, then cool to room temperature, stand and separate, combine the organic phases, spin dry, column chromatography, and use petroleum ether and dichloromethane as developing agents to obtain intermediate D-13-1 (34g, yield 43%).

[0051] HPLC: ≥99.8%;

[0052] Mass spectrometry calculated value: 400.28; mass spectrometry tested value: 400.30.

[0053] Step 2: First, add 425ml of tetrahydrofuran (THF) to a three-necked flask, then weigh formula D-13-1 (84.79mmol, 33.94g) and add it to the reaction system under nitrogen protection. Add 85ml of n-butyl lithium reagent (n-BuLi) to the system at -78°C. After the addition is complete, keep warm for 1 hour. Finally, add trimethylgermanium chloride (84.79mmol, 12.98g) to the system. After the addition is complete, keep the temperature low for 1 hour, and then naturally warm to room temperature after 1 hour. Add water and ethyl acetate to the system, let the liquid stand, combine the organic phases, spin dry, and column chromatography using petroleum ether and dichloromethane as developing agents to obtain formula D-13-2 (15.85g, 42.67% yield).

[0054] Step 3: Under nitrogen, A-13 (64.43 mmol, 10 g) and IrCl3·3H2O (25.77 mmol, 9 g) were weighed and placed into a reaction system. A mixed solution of 270 ml of ethylene glycol ethyl ether and 90 ml of purified water was added. The mixture was refluxed under nitrogen for 24 hours, then cooled to room temperature. A precipitate was formed, which was filtered, rinsed with water, anhydrous ethanol, and then dried with petroleum ether. This afforded bridging ligand B-13 (10.36 g, 74.96% yield).

[0055] Step 4: Weigh the bridging ligand B-13 (9.65 mmol, 10.36 g), add silver trifluoromethanesulfonate (21.23 mmol, 5.45 g), then add 200 ml of dichloromethane to the system, add 55 ml of methanol, react at room temperature under nitrogen protection for 48 hours, pass through a funnel, and spin dry to obtain the bridging ligand C-13 (11.67 g, yield 84.99%).

[0056] Step 5: Weigh the bridging ligand C-13 (14.68 mmol, 10.44 g) and add the ligand D-13-2 (36.17 mmol, 15.85 g). Add 220 ml of anhydrous ethanol to the system and reflux under nitrogen for 48 hours. Filter with suction, wash with ethanol, and dry. Column chromatography was performed using dichloromethane as the solvent. The filtrate was concentrated to precipitate a solid, yielding iridium complex G-13 (5.22 g, 37.88% yield).

[0057] HPLC:≥99.3%.

[0058] Mass spectrometry calculated value: 939.19; mass spectrometry tested value: 939.12.

[0059] Elemental analysis: theoretical value C, 61.48%; H, 4.08%; Ge, 7.75%; Ir, 20.50%; N, 4.48%; O, 1.71%;

[0060] Test values: C, 61.28%; H, 4.10%; Ge, 7.71%; Ir, 20.58%; N, 4.48%; O, 1.71%.

[0061] Example 2 Preparation of G-27

[0062]

[0063] Step 1: Prepare D-13-1 in the same manner as in Example 1 to obtain intermediate D-27-1 (35 g, yield 42%);

[0064] HPLC:≥99.6%.

[0065] Mass spectrometry calculated value: 400.28; mass spectrometry tested value: 400.19.

[0066] Step 2: First, add 437ml of tetrahydrofuran (THF) to a three-necked flask, then weigh formula D-27-1 (87.43mmol, 35g) and add it to the reaction system under nitrogen protection. Add 90ml of n-butyl lithium reagent (n-BuLi) to the system at -78°C. After the addition is complete, keep warm for 1 hour. Finally, add trimethylgermanium chloride (87.43mmol, 13.39g) to the system. After the addition is complete, keep the temperature low for 1 hour, and then naturally warm to room temperature after 1 hour. Add water and ethyl acetate to the system, let the liquid stand, combine the organic phases, spin dry, and column chromatography using petroleum ether and dichloromethane as the developing solvent to obtain formula D-27-2 (13.5g yield is 35.24%).

[0067] Step 3: Under nitrogen, A-27 (58.05 mmol, 10 g) and IrCl3·3H2O (26.38 mmol, 9.3 g) were weighed and placed into a reaction system. A mixed solution of 270 ml of ethylene glycol ethyl ether and 90 ml of purified water was added. The mixture was refluxed under nitrogen for 24 hours, then cooled to room temperature. A precipitate was formed, which was filtered, rinsed with water, anhydrous ethanol, and then dried with petroleum ether. This afforded bridging ligand B-27 (10.78 g, 72.33% yield).

[0068] Step 4: Weigh the bridging ligand B-27 (9.45 mmol, 10.78 g), add silver trifluoromethanesulfonate (20.79 mmol, 5.34 g), then add 200 ml of dichloromethane and 50 ml of methanol to the system. Under nitrogen protection, react at room temperature for 48 hours, pass through a funnel, and spin dry to obtain the bridging ligand C-27 (12.14 g, yield 86.2%).

[0069] Step 5: Weigh the bridging ligand C-27 (12.32 mmol, 9.18 g) and add the ligand D-27-2 (30.81 mmol, 13.5 g). Add 200 ml of anhydrous ethanol to the system and reflux under nitrogen for 48 hours. Filter with suction, wash with ethanol, and dry. Column chromatography using dichloromethane and petroleum ether as developing solvents is performed. The filtrate is concentrated to precipitate a solid, yielding the iridium metal complex G-27 (4.96 g, 41.36% yield).

[0070] HPLC: ≥99.2%.

[0071] Mass spectrometry calculated value: 973.25; mass spectrometry tested value: 973.18.

[0072] Elemental analysis: theoretical value C, 61.80%; H, 4.98%; Ge, 7.47%; Ir, 19.78%; N, 4.32%; O, 1.65%;

[0073] Test values: C, 61.78%; H, 4.95%; Ge, 7.46%; Ir, 19.84%; N, 4.30%; O, 1.67%.

[0074] Example 3 Preparation of G-86

[0075]

[0076] Step 1: Prepare D-13-1 in the same manner as in Example 1 to obtain intermediate D-86-1 (35.02 g, yield 38%); HPLC: ≥99.5%;

[0077] Mass spectrometry calculated value: 339.19; mass spectrometry tested value: 339.14.

[0078] Step 2: First, add 437ml of tetrahydrofuran (THF) to a three-necked flask, then weigh Formula D-86-1 (103.18mmol, 35g) and add it to the reaction system under nitrogen protection. At -78°C, add 103ml of n-butyl lithium reagent (n-BuLi) to the system. After the addition is complete, keep it warm for 1 hour. Finally, add trimethylgermanium chloride (103.18mmol, 15.8g) dropwise to the system. After the addition is complete, keep it at a low temperature for 1 hour, and then naturally warm it to room temperature after 1 hour. Add water and ethyl acetate to the system, let it stand and separate the liquids. Combine the organic phases, spin dry, and column chromatography using petroleum ether and dichloromethane as the developing solvent to obtain Formula D-86-2 (12.6g, 32.46% yield).

[0079] Step 3: Under nitrogen, A-86 (54.61 mmol, 10 g) and IrCl3·3H2O (24.82 mmol, 8.75 g) were weighed and placed into a reaction system. A mixed solution of 240 ml of ethylene glycol ethyl ether and 80 ml of purified water was added. The mixture was refluxed under nitrogen for 24 hours, then cooled to room temperature. A precipitate was formed, which was filtered, rinsed with water, anhydrous ethanol, and then dried with petroleum ether. This afforded bridging ligand B-86 (10.51 g, 71.61% yield).

[0080] Step 4: Weigh the bridging ligand B-86 (8.87 mmol, 10.51 g), add silver trifluoromethanesulfonate (19.51 mmol, 5.01 g), then add 200 ml of dichloromethane and 50 ml of methanol to the system. Under nitrogen protection, react at room temperature for 48 hours, pass through a funnel, and spin dry to obtain the bridging ligand C-86 (12.02 g, yield 88.3%).

[0081] Step 5: Weigh the bridging ligand C-86 (13.36 mmol, 10.26 g) and add the ligand D-13-2 (33.4 mmol, 12.6 g). Add 200 ml of anhydrous ethanol to the system and reflux under nitrogen for 48 hours. Filter with suction, wash with ethanol, and dry. Column chromatography was performed using dichloromethane as the solvent. The filtrate was concentrated to precipitate a solid, yielding the iridium metal complex G-86 (6.25 g, 50.2% yield).

[0082] HPLC: ≥99%.

[0083] Mass spectrometry calculated value: 932.72; mass spectrometry tested value: 934.23.

[0084] Elemental analysis: theoretical value C, 59.24%; H, 4.65%; Ge, 7.79%; Ir, 20.61%; N, 6.01%; O, 1.72%;

[0085] Test values: C, 59.30%; H, 4.61%; Ge, 7.80%; Ir, 20.57%; N, 5.98%; O, 1.81%.

[0086] Example 4 Preparation of G-118

[0087]

[0088] Step 1: Prepare D-13-1 in the same manner as in Example 1 to obtain D118-1 (36.12 g, yield 37.4%);

[0089] HPLC: ≥99.5%.

[0090] Mass spectrometry calculated value: 400.27; mass spectrometry tested value: 400.17.

[0091] Step 2: First, add 437ml of tetrahydrofuran (THF) to a three-necked flask, then weigh formula D-118-1 (87.44mmol, 35g) and add it to the reaction system under nitrogen protection. At -78°C, add 90ml of n-butyl lithium reagent (n-BuLi) to the system. After the addition is complete, keep it warm for 1 hour. Finally, add trimethylgermanium chloride (87.44mmol, 13.39g) to the system. After the addition is complete, keep it at a low temperature for 1 hour, and then naturally warm it to room temperature after 1 hour. Add water and ethyl acetate to the system, let it stand and separate the liquids. Combine the organic phases, spin dry, and column chromatography using petroleum ether and dichloromethane as the developing solvent to obtain formula D-118-2 (14.4g, 36.55% yield).

[0092] Step 3: Under nitrogen, A-118 (59.09 mmol, 10 g) and IrCl3·3H2O (26.85 mmol, 9.46 g) were weighed and placed into a reaction system. A mixed solution of 270 ml of ethylene glycol ethyl ether and 90 ml of purified water was added. The mixture was refluxed under nitrogen for 24 hours, then cooled to room temperature. A precipitate was formed, which was filtered, rinsed with water, anhydrous ethanol, and then dried with petroleum ether. This yielded bridging ligand B-118 (11 g, 73.24% yield).

[0093] Step 4: Weigh the bridging ligand B-118 (9.7 mmol, 11 g), add silver trifluoromethanesulfonate (21.34 mmol, 5.48 g), then add 220 ml of dichloromethane and 55 ml of methanol to the system. Under nitrogen protection, react at room temperature for 48 hours, pass through a funnel, and spin dry to obtain the bridging ligand C-118 (12.51 g, yield 87.2%).

[0094] Step 5: Weigh the bridging ligand C-118 (13.14 mmol, 9.72 g) and add the ligand D-118-2 (32.86 mmol, 14.4 g). Add 200 ml of anhydrous ethanol to the system and reflux under nitrogen for 48 hours. Filter with suction, wash with ethanol, and dry. Column chromatography was performed using dichloromethane as the solvent. The filtrate was concentrated to precipitate a solid, yielding the iridium metal complex G-118 (5.9 g, 46.52% yield).

[0095] HPLC: ≥99.5%.

[0096] Mass spectrometry calculated value: 965.75; mass spectrometry tested value: 966.02.

[0097] Elemental analysis: theoretical value C, 62.18%; H, 4.38%; Ge, 7.52%; Ir, 19.90%; N, 4.35%; O, 1.66%;

[0098] Test values: C, 62.10%; H, 4.40%; Ge, 7.50%; Ir, 19.95%; N, 4.31%; O, 1.76%.

[0099] Example 5 Preparation of G-202

[0100]

[0101] Step 1: Prepare D-13-1 in the same manner as in Example 1 to obtain intermediate D-202-1 (40 g, yield 41%); HPLC: ≥99.3%.

[0102] Mass spectrometry calculated value: 340.03; mass spectrometry tested value: 340.12.

[0103] Step 2: First, add 437ml of tetrahydrofuran (THF) to a three-necked flask, then weigh Formula D-202-1 (102.93mmol, 35g) and add it to the reaction system under nitrogen protection. At -78°C, add 103ml of n-butyl lithium reagent (n-BuLi) to the system. After the addition is complete, keep the temperature for 1 hour. Finally, add trimethylgermanium chloride (102.93mmol, 15.76g) to the system. After the addition is complete, keep the temperature low for 1 hour, and then naturally warm to room temperature after 1 hour. Water and ethyl acetate are added to the system, and the liquid is separated by standing. The organic phases are combined, spin-dried, and column chromatography is performed using petroleum ether and dichloromethane as developing agents to obtain Formula D-202-2 (15.3g, 39.12% yield).

[0104] Step 3: Under nitrogen, A-202 (59.14 mmol, 10 g) and IrCl3·3H2O (9.47 mmol, 9.47 g) were weighed and placed into a reaction system. A mixed solution of 270 ml of ethylene glycol ethyl ether and 90 ml of purified water was added. The mixture was refluxed under nitrogen for 24 hours, then cooled to room temperature. A precipitate was formed, which was filtered, rinsed with water, anhydrous ethanol, and then dried with petroleum ether. This afforded bridging ligand B-202 (11.22 g, 74.02% yield).

[0105] Step 4: Weigh the bridging ligand B-202 (9.94 mmol, 11.22 g), add silver trifluoromethanesulfonate (21.86 mmol, 5.61 g), then add 224 ml of dichloromethane and 56 ml of methanol to the system. Under nitrogen protection, react at room temperature for 48 hours, pass through a funnel, and spin dry to obtain the bridging ligand C-202 (12.59 g, yield 85.6%).

[0106] Step 5: Weigh the bridging ligand C-202 (16.1 mmol, 11.91 g) and add the ligand D-202-2 (40.22 mmol, 15.3 g). Add 220 ml of anhydrous ethanol to the system and reflux under nitrogen for 48 hours. Filter with suction, wash with ethanol, and dry. Column chromatography using dichloromethane as the developing solvent is performed. The filtrate is concentrated to precipitate a solid, yielding the iridium metal complex G-202 (6.49 g, 44.4% yield).

[0107] HPLC:≥99.3%.

[0108] Mass spectrometry calculated value: 909.22; mass spectrometry tested value: 908.69.

[0109] Elemental analysis: theoretical value C, 58.22%; H, 4.66%; Ge, 8.00%; Ir, 21.18%; N, 6.17%; O, 1.76%;

[0110] Test values: C, 58.26%; H, 4.61%; Ge, 7.99%; Ir, 21.21%; N, 6.11%; O, 1.79%.

[0111] Example 6 Preparation of G-210

[0112]

[0113] Step 1: Prepare D-13-1 in the same manner as in Example 1 to obtain intermediate D-210-1 (35.04 g, yield 41%); HPLC: ≥99.3%.

[0114] Mass spectrometry calculated value: 405.99; mass spectrometry tested value: 406.12.

[0115] Step 2: First, add 437ml of tetrahydrofuran (THF) to a three-necked flask, then weigh Formula D-210-1 (85.87mmol, 35g) and add it to the reaction system under nitrogen protection. At -78°C, add 86ml of n-butyl lithium reagent (n-BuLi) to the system. After the addition is complete, keep it warm for 1 hour. Finally, add trimethylgermanium chloride (85.87mmol, 13.15g) dropwise to the system. After the addition is complete, keep it at a low temperature for 1 hour, and then naturally warm it to room temperature after 1 hour. Water and ethyl acetate are added to the system, the liquid is separated by standing, the organic phases are combined, spin-dried, and column chromatography is performed using petroleum ether and dichloromethane as developing agents to obtain Formula D-210-2 (15.3g, 39.42% yield).

[0116] Step 3: Under nitrogen, A-210 (mmol, 10 g) and IrCl3·3H2O (mmol, 9.47 g) were weighed and placed into a reaction system. A mixed solution of 270 ml of ethylene glycol ethyl ether and 90 ml of purified water was added. The mixture was refluxed under nitrogen for 24 hours, then cooled to room temperature. A precipitate was formed, filtered, rinsed with water, anhydrous ethanol, and then dried with petroleum ether. This yielded bridging ligand B-210 (10.66 g, 70.34% yield).

[0117] Step 4: Weigh the bridging ligand B-210 (9.44 mmol, 10.66 g), add silver trifluoromethanesulfonate (20.76 mmol, 5.34 g), then add 200 ml of dichloromethane and 50 ml of methanol to the system. Under nitrogen protection, react at room temperature for 48 hours, pass through a funnel, and spin dry to obtain the bridging ligand C-210 (12.11 g, yield 86.7%).

[0118] Step 5: Weigh the bridging ligand C-210 (13.71 mmol, 10.14 g) and add the ligand D-210-2 (34.29 mmol, 15.3 g). Add 220 ml of anhydrous ethanol to the system and reflux under nitrogen for 48 hours. Filter with suction, wash with ethanol, and dry. Column chromatography using dichloromethane as the solvent and concentration of the filtrate yields the iridium complex G-210 (6.54 g, 49.06% yield).

[0119] HPLC: ≥99%.

[0120] Mass spectrometry calculated value: 972.67; mass spectrometry tested value: 972.22.

[0121] Elemental analysis: theoretical value C, 55.57%; H, 3.94%; F, 5.86%; Ge, 7.47%; Ir, 19.76%; N, 5.76%; O, 1.64%; tested value C, 55.63%; H, 3.94%; F, 5.81%; Ge, 7.45%; Ir, 19.74%; N, 5.82%; O, 1.66%.

[0122] The synthesis methods of other iridium metal complexes G-1, G-3, G-22, G-30, G-46, G-64, G-87, G-103, G-133, G-162, and G-214 are the same as those in the above embodiments, and are not described in detail here. The molecular formulas or mass spectra of other synthesized iridium metal complexes are shown in Table 1 below:

[0123] Table 1 Molecular formula and mass spectrum of iridium metal complexes

[0124]

[0125]

[0126] In order to further describe the present invention, more specific embodiments are listed below:

[0127] Example 7: Fabrication of an organic electroluminescent device containing compound G-13

[0128] The ITO glass substrate with a coating thickness of 150nm was washed twice in distilled water and ultrasonically washed for 30 minutes, and then repeatedly washed twice with distilled water and ultrasonically washed for 10 minutes. After the distilled water washing was completed, the substrate was ultrasonically washed in sequence with isopropyl alcohol, acetone, methanol and other solvents, and then dried. The substrate was transferred to a plasma cleaning machine, washed for 5 minutes, and sent to a vapor deposition machine.

[0129] First, 60nm of 4,4',4"-tris[2-naphthylphenylamino]triphenylamine ("2-TNATA") was vacuum-deposited on the ITO (anode) as a hole injection layer; then 60nm of N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB) was vacuum-deposited on the hole injection layer as a hole transport layer; and the light-emitting layer was vacuum-deposited on the hole transport layer. Among them, the main material of the light-emitting layer, 4,4'-N,N'-biphenyldicarbazole (CBP), and the dopant material compound G-13 were mixed in a weight ratio of 90:1. 0 mixture was evaporated to a thickness of 30nm to form the light-emitting layer; then, BAlq was vacuum-evaporated to a thickness of 10nm to form the hole-blocking layer; then, Alq3 was vacuum-evaporated to a thickness of 40nm on the hole-blocking layer to form the electron-transporting layer; then, LiF was vacuum-evaporated to a thickness of 0.2nm on top of this to form the electron-injection layer; and finally, Al was vacuum-evaporated to a thickness of 150nm on the electron-injection layer to form the cathode. This method resulted in an electroluminescent device. The performance and luminescence characteristics of the resulting electroluminescent device were tested under constant brightness conditions to evaluate the driving voltage, maximum external quantum efficiency, and phosphorescence lifetime.

[0130] The electroluminescent devices of Examples 8 to 25 were prepared by referring to the method of Example 7, with the only difference being:

[0131] The doping material G-13 is replaced with G-1, G-3, G-22, G-27, G-30, G-46, G-64, G-86, G-87, G-103, G-118, G-133, G-162, G-202, G-210, and G-214.

[0132] Comparative Example

[0133] An organic electroluminescent device was prepared in the same manner as in Example 7, except that the light-emitting layer doping material G-13 was replaced with compound Ir(ppy)3, compound 1, and compound 2. The structure thereof is as follows:

[0134]

[0135] The prepared organic electroluminescent device was subjected to the same test as in Example 7. The results are shown in Table 2.

[0136] Table 2 Test results of organic electroluminescent devices

[0137]

[0138]

[0139] As can be seen from Table 2, 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, an improved maximum external quantum efficiency, and a significantly improved lifespan compared to the electroluminescent device prepared using the comparative compound Ir(ppy)3, compound 1, and compound 2 as the light-emitting layer doping material.

[0140] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one 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 present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An organometallic iridium complex luminescent material, characterized in that: The organic iridium metal complex luminescent material is selected from the following structures:

2. Use of the organometallic iridium complex luminescent material according to claim 1 in an organic electroluminescent device.

3. The use according to claim 2, characterized in that The organic electroluminescent device comprises: a first electrode, a second electrode and an organic layer disposed between the two electrodes; The organic layer contains the organometallic iridium complex as claimed in claim 1 ; and the organometallic iridium complex is in a single form or mixed with other substances in the organic layer.

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