Metal iridium complex, preparation method thereof and organic electroluminescent device

Abstract

The invention belongs to the field of organic electroluminescence, and provides a metal iridium complex, a preparation method thereof and an organic electroluminescent device. The structural general formula of the metal iridium complex is shown in the specification. The metal iridium complex provided by the invention has the advantages of low evaporation temperature, high photo-electrochemical stability, high luminous efficiency, long device life and the like, the preparation method provided by the invention is simple in process, the prepared product is high in purity and suitable for industrial production, and the problem that the luminous efficiency of an existing luminous material is insufficient is solved.

Description

Technical Field

[0001] The invention belongs to the field of organic electroluminescence, and specifically relates to a metal iridium complex and a preparation method thereof, and an organic electroluminescent device. Background Art

[0002] At present, organic electroluminescent devices (OLEDs), as a new generation of display technology, have received more and more attention in both display and lighting technology, and have a wide range of application prospects. However, compared with market application requirements, the performance of OLED devices such as luminous efficiency, driving voltage, and service life still needs to be further strengthened and improved.

[0003] Generally speaking, the basic structure of an OLED device is a thin film of organic materials with various functions sandwiched between metal electrodes. Driven by electric current, holes and electrons are injected from the positive and negative electrodes respectively. After moving a certain distance, the holes and electrons are recombined in the light-emitting layer and released in the form of light or heat, thus generating the light emission of the OLED. However, organic functional materials are the core components of organic electroluminescent devices. The thermal stability, photochemical stability, electrochemical stability, quantum yield, film-forming stability, crystallinity, color saturation, etc. of the materials are the main factors affecting the performance of the device.

[0004] Generally, organic functional materials include fluorescent materials and phosphorescent materials. Fluorescent materials are usually small organic molecules, and generally can only utilize 25% of the singlet state to emit light, so the luminous efficiency is relatively low. However, due to the spin-orbit coupling effect caused by the heavy atom effect, phosphorescent materials can utilize the energy of 75% of triplet excitons in addition to 25% of the singlet state, so the luminous efficiency is higher.

[0005] Compared with fluorescent materials, phosphorescent materials started later, and the thermal stability, lifespan, and color saturation of currently disclosed organic phosphorescent materials need to be improved. Invention patent CN107973823A discloses a class of quinoline iridium compounds, the color saturation and device performance of which, especially the luminous efficiency and device life, need to be improved; invention patent CN106459114A discloses a class of iridium compounds coordinated by β-diketone ligands, which have high sublimation temperatures and poor color saturation, especially the device luminous efficiency and device life, which need to be further improved; invention patent CN111377969A discloses a class of dibenzofuran-isoquinoline iridium complexes, the device performance of which, especially the color saturation, cannot meet the display color gamut requirements of BT2020, which needs to be further improved.

[0006] Therefore, how to develop a metal iridium complex material with high luminescence efficiency, low voltage, low evaporation temperature, high light and electrochemical stability, high luminescence efficiency and long device life is a technical problem that needs to be solved at present. Summary of the invention

[0007] In view of this, the present invention provides a metal iridium complex and a preparation method thereof, and an organic electroluminescent device.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] The first technical purpose of the present invention is to provide a metal iridium complex, the structure of which is shown in Formula I:

[0010]

[0011] in,

[0012] R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 , R 11 represents a single substituent or no substituent; R 12 , R 13 and R 14 represents a single substituent or no substituent;

[0013] R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 and R 11 independently selected from hydrogen, deuterium, halogen, nitro, trimethylsilyl, trimethylgermanium, -CN, substituted or unsubstituted C1-C 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 Alkylamino, substituted or unsubstituted C2-C 60 Alkenyl, substituted or unsubstituted C2-C 60 Alkyne, substituted or unsubstituted C4-C 60 heterocyclic group; and said R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 , R 11 Each independently forms a substituted or unsubstituted C3-C30 aliphatic ring, a substituted or unsubstituted C6-C18 aromatic ring, or a substituted or unsubstituted C4-C18 aromatic heterocyclic ring with the ring in which it is located;

[0014] R 12 , R 13 and R 14 Independently selected from hydrogen, methyl, propyl, tert-butyl, pentyl, deuterium, -CN, -F, -CF3, dimethylhexyl;

[0015] X is independently selected from O, Ge, S, Si, Se;

[0016] Y is independently selected from hydrogen, deuterium, -F, -CN, methyl, ethyl, propyl, phenyl, tert-butylbenzene, and phenyl substituted with cyano.

[0017] Preferably, R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 and R 11 is independently selected from hydrogen, deuterium, thiophene, furan, methyl, ethyl, propyl, tert-butyl, neopentyl, phenyl, deuterated phenyl, cyano-substituted phenyl, tert-butylbenzene, alkyl-substituted phenyl, nitro, trimethylsilyl, trimethylgermanium, -CN, halogen; Y is independently selected from hydrogen, deuterium, -F, -CN, methyl.

[0018] As a further embodiment of the present invention, hydrogen in the above-mentioned groups or substituent groups may be substituted with deuterium.

[0019] As a further embodiment of the present invention, the metal iridium complex is selected from any one of the following structures:

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083] It should be noted that only some specific structural forms are listed above, but this series of metal iridium complexes are not limited to the above molecular structures. Any simple transformation of some simple groups and their substituted groups and substitution positions can obtain other specific molecular structures, which will not be repeated here.

[0084] The second object of the present invention is to provide a method for preparing the above-mentioned metal iridium complex, which can be prepared by methods known to those skilled in the art. Alternatively, the following reaction process is preferably used for preparation, comprising the following steps:

[0085] (1) providing a compound II represented by the following structural formula:

[0086]

[0087] (2) reacting the compound II provided in step (1) with iridium trichloride to obtain a compound III represented by the following structural formula:

[0088]

[0089] (3) providing a compound IV represented by the following structural formula:

[0090]

[0091] (4) reacting the compound IV provided in step (3) with the compound III obtained in step (2) to obtain the metal iridium complex;

[0092] Among them, R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 , R 11 , R 12 , R 13 and R 14 The representative groups are the same as mentioned above.

[0093] As a further embodiment of the present invention, 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.

[0094] Preferably, in the reaction of compound II provided in step (1) with iridium trichloride, the solvent is a mixed solution of ethylene glycol ethyl ether and ultrapure water, the ratio of ethylene glycol ethyl ether to ultrapure water is 3:1; the amount of the solvent is 15-30 times the mass of the iridium trichloride, and the reaction time is 24-30 hours.

[0095] As a further embodiment of the present invention, the compound IV provided in step (3) is reacted with the compound III obtained in step (2), and the molar ratio of the compound III to the compound IV is 1:(2.5-8).

[0096] In a further embodiment of the present invention, the compound IV provided in step (3) is reacted with the compound III obtained in step (2), the base used is anhydrous potassium carbonate or anhydrous sodium carbonate, the solvent is ethylene glycol ethyl ether, the amount of the solvent is 10-30 times the mass of the compound III, and the reaction time is 10-30 hours, preferably 20-24 hours.

[0097] The third object of the present invention is to provide the use of the metal iridium complex in an organic electroluminescent device.

[0098] An electroluminescent device, comprising the metal iridium 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 metal iridium complex of the present invention; the metal iridium complex is present in the organic layer in a single form or mixed with other substances.

[0099] The organic layer at least includes 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.

[0100] The organic electroluminescent device comprises at least one functional layer, namely the metal iridium complex of the present invention.

[0101] The organic electroluminescent device comprises a light-emitting layer, and the light-emitting layer contains the metal iridium complex of the present invention.

[0102] The light-emitting layer of the organic electroluminescent device comprises a main material and a doping material, wherein the doping material is the metal iridium complex of the present invention, and the mixing ratio of the main material to the doping material is 90:10 to 99.5:0.5.

[0103] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0104] The present invention generates a metal iridium complex by selecting a specific heterocyclic ligand for combination, changing the combination of substituents on the ligand, adding a branched alkyl group, a substituted or unsubstituted aryl group and a substituted or unsubstituted alkyl group, thereby improving the intermolecular spatial configuration and having a good spatial twisting ability, thereby avoiding carrier migration. After the metal iridium complex is used as a specific doping material for a light-emitting layer and applied to an organic electroluminescent device, the wavelength of the metal iridium complex can be adjusted, the voltage is relatively low, and the power efficiency is significantly improved. The metal iridium complex has the advantages of low evaporation temperature, high light and electrochemical stability, high luminous efficiency, long device life, etc. In addition, the preparation method of the metal iridium complex provided in the embodiment of the present invention has a simple process, a high purity of the prepared product, and is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0105] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0106] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of compound Z-94. DETAILED DESCRIPTION

[0107] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0108] The embodiment of the invention discloses a metal iridium complex and a preparation method thereof, and an organic electroluminescent device.

[0109] In addition, it should be noted that the numerical 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 value.

[0110] Among them, formula II-94 is synthesized in three steps, and the specific operations are as follows:

[0111]

[0112] In the first step, the reactor was replaced with nitrogen. Under a nitrogen atmosphere, compound 9H-indeno[2,1-c]pyridine-9-ol (CAS: 1333363-03-8) (200 mmol) and 137.25 ml of dichloromethane were added to the reactor and completely dissolved in dichloromethane. The temperature was lowered to 0°C. N-bromosuccinimide (NBS) (CAS: 128-08-5) (200 mmol) was added under a nitrogen atmosphere. The mixture was kept at 0°C for 3 hours under the protection of a nitrogen atmosphere. The mixture was concentrated under reduced pressure using a rotary evaporator. The crude product was subjected to column chromatography (200-300 mesh, 500 g) to remove impurities. The developing agent was EA: PE = 1:20. The receiving solution was vortexed until no liquid flowed out. The mixture was dried under vacuum to obtain the intermediate 1 shown as the compound (11.48 g, with a yield of 22%).

[0113] HPLC purity was greater than 99.5%.

[0114] Mass spectrum: Test value is 261.13.

[0115] 1 H NMR (400MHz, Chloroform-d) δ8.29(d,1H),8.06-7.98(m,1H),7.76(d,1H),7.64-7.57(m,1H),7.41-7.31(m,2H),7.13(d,1H),4.49(d,1H).

[0116]

[0117] In the second step, under nitrogen protection, intermediate 1 (180 mmol) and anhydrous potassium carbonate (540 mmol) were put into the reaction system, 1000 ml toluene, 500 ml anhydrous ethanol, 500 ml purified water were added, Pd(PPh3)4 (1.5 mmol) was added under nitrogen protection, (1-fluoro-2-naphthyl)boric acid (CAS: 2000289-18-7) (180 mmol) was added in three batches every 1 hour, after the addition was completed, refluxed at 100 ° C for 24 h under nitrogen protection, and then cooled to 25 ° C. After the reaction was cooled, it was extracted with ethyl acetate, washed three times with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The crude product was column chromatographed (200-300 mesh, 450 g) to remove impurities, the developing agent EA: PE = 1: 10, the receiving liquid was vortexed until no liquid flowed out, and vacuum dried to obtain the intermediate 2 of the compound shown (28.26 g, yield 48%).

[0118] HPLC purity was greater than 99.5%.

[0119] Mass spectrum: Test value is 327.23.

[0120]

[0121] In the third step, under the protection of nitrogen, intermediate 2 (70 mmol), potassium carbonate (210 mmol) and DMF (500 mL) were added to the reaction system in sequence, and then heated and stirred at 100 ° C for 15 h. After the reaction was complete, it was cooled, filtered through diatomaceous earth, and the organic phase was washed with saturated brine, extracted with ethyl acetate three times, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The crude product was purified by column chromatography to remove impurities, and eluted with 10% (v / v) dichloromethane / petroleum ether solution to obtain Formula II-94 (9.67 g, yield 45%).

[0122] HPLC purity was greater than 99.5%.

[0123] Mass spectrum: Test value is 307.30.

[0124] 1H NMR(400MHz,Chloroform-d)δ8.61(d,1H),8.12-8.07(m,1H),7.98-7.91(m,2H),7.83-7.77( m,1H),7.77-7.68(m,2H),7.55(t,1H),7.56-7.49(m,2H),7.48-7.38(m,2H),7.27(ddd,1H).

[0125] Intermediate 4 was synthesized in two steps, and the specific operation is as follows:

[0126]

[0127] The first step, under nitrogen protection, take intermediate 1 (180mmol), anhydrous potassium carbonate (540mmol) into the reaction system, add 1000ml toluene, 500mL anhydrous ethanol, 500mL purified water, add Pd(PPh3)4 (1.5mmol) under nitrogen protection, add (4-bromo-1-fluoronaphthalene-2-yl)boric acid (CAS: 913836-09-6) (180mmol) in three batches every 1 hour, after the addition, reflux at 100°C for 24h under nitrogen protection, then cool to 25°C, after the reaction is cooled, extract with ethyl acetate, wash three times with saturated brine, dry with anhydrous magnesium sulfate, concentrate under reduced pressure, and remove impurities by column chromatography (200-300 mesh, 450g) of the crude product, the developing agent EA:PE=1:10, the receiving liquid is vortexed until no liquid flows out, and vacuum dried to obtain the intermediate 2 of the compound shown (33.54g, yield 46%).

[0128] HPLC purity was greater than 99.5%.

[0129] Mass spectrum: Test value is 405.17.

[0130]

[0131] In the second step, under nitrogen protection system, intermediate 3 (70mmol), potassium carbonate (210mmol) and DMF (500mL) were added to the reaction system in sequence, and then heated and stirred at 100°C for 15h. After the reaction was complete, it was cooled, filtered through diatomaceous earth, and the organic phase was washed with saturated brine, extracted with ethyl acetate three times, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The crude product was purified by column chromatography to remove impurities, and eluted with 20% (v / v) dichloromethane / petroleum ether solution to obtain intermediate 4 (11.32g, yield 42%).

[0132] HPLC purity was greater than 99.5%.

[0133] Mass spectrum: Test value is 385.18.

[0134] 1 H NMR(400MHz,Chloroform-d)δ8.61(d,1H),8.13(s,1H),8.08-8.03(m,1H),7.97-7.88(m,2 H),7.83-7.77(m,1H),7.58-7.53(m,2H),7.45(td,1H),7.44-7.36(m,2H),7.27(ddd,1H).

[0135] Example 1

[0136]

[0137] In the first step, under a nitrogen protection system, ligand II-94 (25 mmol) and IrC13·3H2O (10 mmol) were weighed and put into the reaction system, and a mixed solution of 180 ml of ethylene glycol ethyl ether and 60 ml of pure water was added. The mixture was refluxed at 110°C for 24 h under nitrogen protection, and then cooled to room temperature. A precipitate was precipitated. The precipitate was filtered, washed with water, anhydrous ethanol, and petroleum ether in turn, and dried at 50°C for at least 10 h to obtain a bridged ligand III-94 (4.45 g, with a yield of 53%).

[0138] In the second step, the bridging ligand of formula III-94 (5mmol) was weighed, anhydrous potassium carbonate (50mmol) was added, and then 144ml of anhydrous ethylene glycol ether was added to the system, nitrogen was replaced three times, and 2,4,6-trimethyl-3,5-heptanedione (CAS: 642475-10-3) (15mmol) was added under nitrogen. Under nitrogen protection, the mixture was refluxed at 110°C for 24h, cooled, filtered, washed with alcohol, and dried at 50°C for at least 10h. Dichloromethane was used as solvent, and neutral alumina column chromatography was used. The filtrate was concentrated and solid precipitated to finally obtain the organic phosphorescent material represented by formula Z-94 (2.63g, yield 54%).

[0139] HPLC purity was greater than 99.5%.

[0140] Mass spectrum: Test value is 974.39.

[0141] Elemental Analysis:

[0142] Calculated values: C: 66.58; H: 4.24; N: 2.88; O: 6.62.

[0143] The test values ​​are C:66.59; H:4.23; N:2.86; O:6.57.

[0144] The H NMR spectrum of compound Z-94 is as follows Figure 1 shown.

[0145] Example 2

[0146]

[0147] In the first step, under nitrogen protection, intermediate 4 (180 mmol) and anhydrous potassium carbonate (540 mmol) were put into the reaction system, 1000 ml toluene, 500 ml anhydrous ethanol, 500 ml purified water were added, Pd(PPh3)4 (1.5 mmol) was added under nitrogen protection, phenylboric acid (CAS: 98-80-6) (180 mmol) was added in three batches every 1 hour, after the addition was completed, refluxed at 100 ° C for 24 h under nitrogen protection, and then cooled to 24 ° C. After the reaction was cooled, it was extracted with ethyl acetate, washed three times with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The crude product was column chromatographed (200-300 mesh, 450 g) to remove impurities, the developing agent EA: PE = 1: 10, the receiving liquid was vortexed until no liquid flowed out, and vacuum dried to obtain the compound shown in formula II-275 (33.10 g, yield 48%).

[0148] HPLC purity was greater than 99.5%.

[0149] Mass spectrum: Test value is 383.26.

[0150] In the second step, under the protection of nitrogen, weigh the ligand II-275 (25 mmol) and IrC13·3H2O (10 mmol) and put them into the reaction system, add a mixed solution of 180 ml of ethylene glycol ethyl ether and 60 ml of pure water, reflux at 110°C for 24 hours under nitrogen protection, and then cool to room temperature. A precipitate is precipitated, and the precipitate is filtered, washed with water, anhydrous ethanol, and petroleum ether in turn, and dried at 50°C for at least 10 hours to obtain the bridged ligand III-275 (4.96 g, yield 50%).

[0151] The third step is to weigh the bridging ligand III-275 (5mmol), add anhydrous potassium carbonate (50mmol), and then add 144ml of anhydrous ethylene glycol ether to the system, replace nitrogen three times, add 3-methylpentane-2,4-dione (CAS: 815-57-6) (15mmol) under nitrogen, reflux at 110°C for 24h under nitrogen protection, cool, filter, wash with alcohol, dry at 50°C for at least 10h, use dichloromethane as solvent, and use neutral alumina column chromatography. The filtrate is concentrated and the solid is precipitated to finally obtain the organic phosphorescent material represented by formula Z-275 (2.89g, yield 54%).

[0152] HPLC purity was greater than 99.5%.

[0153] Mass spectrum: test value is 1070.42.

[0154] Elemental Analysis:

[0155] Calculated values: C: 69.58; H: 3.86; N: 2.62; O: 5.98.

[0156] The test values ​​are C:69.59; H:3.85; N:2.61; O:5.99.

[0157] 1 H NMR(400MHz,Chloroform-d)δ8.69(d,2H),8.03(td,6H),7.85-7.79(m,2H),7.61-7.5 6(m,4H),7.47-7.30(m,16H),7.25(ddd,,2H),2.24(s,3H),2.11(q,3H),1.70(q,3H).

[0158] Example 3

[0159]

[0160] In the first step, under nitrogen protection, intermediate 4 (180 mmol) and anhydrous potassium carbonate (540 mmol) were put into the reaction system, 1000 ml toluene, 500 ml anhydrous ethanol, 500 ml purified water were added, Pd (PPh3) 4 (1.5 mmol) was added under nitrogen protection, dibenzofuran-4-boric acid (CAS: 100124-06-9) (180 mmol) was added in three batches every 1 hour, after the addition was completed, refluxed at 100 ° C for 24 h under nitrogen protection, and then cooled to 24 ° C. After the reaction was cooled, it was extracted with ethyl acetate, washed three times with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The crude product was column chromatographed (200-300 mesh, 450 g) to remove impurities, the developing agent EA: PE = 1:20, the receiving liquid was vortexed until no liquid flowed out, and vacuum dried to obtain the compound shown in formula II-456 (40.03 g, yield 47%).

[0161] HPLC purity was greater than 99.5%.

[0162] Mass spectrum: Test value is 473.25.

[0163] In the second step, under the protection of nitrogen, weigh ligand II-456 (25 mmol) and IrC13·3H2O (10 mmol) into the reaction system, add a mixed solution of 180 ml of ethylene glycol ethyl ether and 60 ml of pure water, reflux at 110°C for 24 hours under nitrogen protection, and then cool to room temperature. A precipitate is precipitated, and the precipitate is filtered, washed with water, anhydrous ethanol, and petroleum ether in turn, and dried at 50°C for at least 10 hours to obtain a bridged ligand III-456 (5.98 g, yield 51%).

[0164] The third step is to weigh the bridging ligand of formula III-456 (5mmol), add anhydrous potassium carbonate (50mmol), and then add 144ml of anhydrous ethylene glycol ether to the system, replace nitrogen three times, add 1,3-diisopropyl-1,3-propanedione (CAS: 424822-99-1) (15mmol) under nitrogen, reflux at 110°C for 24h under nitrogen protection, cool, filter, wash with alcohol, dry at 50°C for at least 10h, use dichloromethane as solvent, and perform neutral alumina column chromatography. The filtrate is concentrated and the solid is precipitated to finally obtain the organic phosphorescent material represented by formula Z-456 (3.10g, yield 48%).

[0165] HPLC purity was greater than 99.5%.

[0166] Mass spectrum: Test value is 1292.46.

[0167] Elemental Analysis:

[0168] Calculated values: C: 71.56; H: 3.98; N: 2.17; O: 7.43.

[0169] The test values ​​are C:71.59; H:3.94; N:2.18; O:7.41.

[0170] 1 H NMR(400MHz,Chloroform-d)δ8.67(d,2H),8.10-8.00(m,8H),7.86(dd,2H),7.84-7.79(m,2H),7.65-7. 56(m,6H),7.54-7.33(m,14H),7.25(ddd,2H),5.91(d,1H),2.84(p,1H),2.67(pd,1H),1.09(ddd,12H).

[0171] Example 4

[0172] Formula II-640 is synthesized in four steps, and the specific operations are as follows:

[0173]

[0174] In the first step, a nitrogen-displaced reactor was used. Under a nitrogen atmosphere, compound 3,9-dimethyl-9H-indeno[2,1-c]pyridine-9-ol (CAS: 72562-04-0) (200 mmol) and 400 ml of dichloromethane were added to the reactor and completely dissolved in dichloromethane. The temperature was lowered to -78°C, BBr3 (60 mmol) was dissolved in dichloromethane and added dropwise within 2 hours. After the addition was completed, the reaction was restored to room temperature for 6 hours. After the reaction was completed, ice water was slowly added to quench, and NaHCO3 was adjusted to neutral. After extraction, dichloromethane was removed by vacuum distillation to precipitate solids, which were filtered, washed with alcohol, and dried at 70°C for at least 12 hours. Dichloromethane was used as a solvent, and neutral alumina column chromatography was used. The filtrate was concentrated and solids precipitated to finally obtain the compound 5 (13.00 g, yield 33%).

[0175] HPLC purity was greater than 99.5%.

[0176] Mass spectrum: Test value is 197.22.

[0177] 1 H NMR (400MHz, Chloroform-d) δ8.65(dd,1H),8.40(d,1H),7.74(dd,1H),7.59(d,1H),7.46-7.41(m,1H),7.40-7.30(m,2H),4.84(s,1H),1.80(s,3H).

[0178]

[0179] In the second step, the reactor was replaced with nitrogen. Under a nitrogen atmosphere, intermediate 5 (200 mmol) and 137.25 ml of dichloromethane were added to the reactor and completely dissolved in dichloromethane. The temperature was lowered to 0°C. N-bromosuccinimide (NBS) (CAS: 128-08-5) (200 mmol) was added under a nitrogen atmosphere. The mixture was kept at 0°C for 3 hours under the protection of a nitrogen atmosphere. The mixture was concentrated under reduced pressure using a rotary evaporator. The crude product was subjected to column chromatography (200-300 mesh, 500 g) to remove impurities. The developing agent was EA:PE = 1:18. The receiving solution was vortexed until no liquid flowed out. The mixture was dried under vacuum to obtain the intermediate 6 (13.20 g, with a yield of 24%).

[0180] HPLC purity was greater than 99.5%.

[0181] Mass spectrum: Test value 275.10.

[0182] 1H NMR (400MHz, Chloroform-d) δ8.27(d,1H),7.84-7.77(m,1H),7.61(d,1H),7.51-7.44(m,1H),7.39-7.30(m,2H),5.03(s,1H),1.85(s,3H).

[0183]

[0184] The third step, under nitrogen protection, take intermediate 6 (180mmol), anhydrous potassium carbonate (540mmol) into the reaction system, add 1000ml toluene, 500mL anhydrous ethanol, 500mL purified water, add Pd(PPh3)4 (1.5mmol) under nitrogen protection, add (1-fluoro-2-naphthyl)boric acid (CAS: 2000289-18-7) (180mmol) in three batches every 1 hour, after the addition, reflux at 100℃ for 24h under nitrogen protection, then cool to 25℃, after the reaction is cooled, extract with ethyl acetate, wash three times with saturated brine, dry with anhydrous magnesium sulfate, concentrate under reduced pressure, and remove impurities by column chromatography (200-300 mesh, 450g) of the crude product, the developing agent EA:PE=1:12, the receiving liquid is vortexed until no liquid flows out, and vacuum dried to obtain the intermediate 7 shown as the compound (26.40g, yield 43%).

[0185] HPLC purity was greater than 99.5%.

[0186] Mass spectrum: Test value is 341.34.

[0187]

[0188] In the fourth step, under the protection of nitrogen, intermediate 7 (70 mmol), potassium carbonate (210 mmol) and DMF (500 mL) were added to the reaction system in sequence, and then heated and stirred at 100 ° C for 15 h. After the reaction was complete, it was cooled, filtered through diatomaceous earth, and the organic phase was washed with saturated brine, extracted with ethyl acetate three times, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The crude product was purified by column chromatography to remove impurities, and eluted with 10% (v / v) dichloromethane / petroleum ether solution to obtain Formula II-640 (12.14 g, yield 54%).

[0189] HPLC purity was greater than 99.5%.

[0190] Mass spectrum: Test value is 321.23.

[0191] 1H NMR(400MHz,Chloroform-d)δ8.61(d,1H),8.02-7.93(m,2H),7.77-7.69(m,2H),7.63(dd,1H) ,7.59(dd,1H),7.55-7.49(m,1H),7.47(td,1H),7.42-7.34(m,2H),7.31(td,1H),1.93(s,3H) .

[0192] Intermediate 9 was synthesized in two steps, and the specific operations are as follows:

[0193]

[0194] The first step, under nitrogen protection, take intermediate 6 (180mmol), anhydrous potassium carbonate (540mmol) into the reaction system, add 1000ml toluene, 500mL anhydrous ethanol, 500mL purified water, add Pd(PPh3)4 (1.5mmol) under nitrogen protection, add (4-bromo-1-fluoronaphthalene-2-yl)boric acid (CAS: 913836-09-6) (180mmol) in three batches every 1 hour, after the addition, reflux at 100°C for 24h under nitrogen protection, then cool to 25°C, after the reaction is cooled, extract with ethyl acetate, wash three times with saturated brine, dry with anhydrous magnesium sulfate, concentrate under reduced pressure, and remove impurities by column chromatography (200-300 mesh, 450g) of the crude product, the developing agent EA:PE=1:10, the receiving liquid is vortexed until no liquid flows out, and vacuum dried to obtain the intermediate 8 shown as the compound (34.70g, yield 46%).

[0195] HPLC purity was greater than 99.5%.

[0196] Mass spectrum: Test value is 419.21.

[0197]

[0198] In the second step, under the protection of nitrogen, intermediate 8 (70mmol), potassium carbonate (210mmol) and DMF (500mL) were added to the reaction system in sequence, and then heated and stirred at 100°C for 15h. After the reaction was complete, it was cooled, filtered through diatomaceous earth, and the organic phase was washed with saturated brine, extracted with ethyl acetate three times, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The crude product was purified by column chromatography to remove impurities, and eluted with 18% (v / v) dichloromethane / petroleum ether solution to obtain intermediate 9 (11.73g, yield 42%).

[0199] HPLC purity was greater than 99.5%.

[0200] Mass spectrum: Test value is 399.13.

[0201] 1 H NMR(400MHz,Chloroform-d)δ8.63(d,1H),8.12(s,1H),8.08-8.02(m,1H),7.73(dd, 1H),7.66-7.57(m,2H),7.45(td,1H),7.44-7.34(m,3H),7.30(td,1H),1.93(s,3H).

[0202]

[0203] In the first step, under nitrogen protection, intermediate 9 (180 mmol) and anhydrous potassium carbonate (540 mmol) were put into the reaction system, 1000 ml toluene, 500 ml anhydrous ethanol, 500 ml purified water were added, Pd (PPh3) 4 (1.5 mmol) was added under nitrogen protection, 4-methylphenylboronic acid (CAS: 5720-05-8) (180 mmol) was added in three batches every 1 hour, after the addition was completed, refluxed at 100 ° C for 24 h under nitrogen protection, and then cooled to 24 ° C. After the reaction was cooled, it was extracted with ethyl acetate, washed three times with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The crude product was column chromatographed (200-300 mesh, 450 g) to remove impurities, the developing agent EA: PE = 1:20, the receiving liquid was vortexed until no liquid flowed out, and vacuum dried to obtain the compound shown in formula II-640 (42.93 g, yield 58%).

[0204] HPLC purity was greater than 99.5%.

[0205] Mass spectrum: Test value is 411.27.

[0206] In the second step, under the protection of nitrogen, weigh the ligand II-640 (25 mmol) and IrC13·3H2O (10 mmol) and put them into the reaction system, add a mixed solution of 180 ml of ethylene glycol ethyl ether and 60 ml of pure water, reflux at 110°C for 24 hours under nitrogen protection, and then cool to room temperature. A precipitate is precipitated, and the precipitate is filtered, washed with water, anhydrous ethanol, and petroleum ether in turn, and dried at 50°C for at least 10 hours to obtain the bridged ligand III-640 (5.35 g, yield 51%).

[0207] The third step is to weigh the bridging ligand III-640 (5 mmol), add anhydrous potassium carbonate (50 mmol), and then add 144 ml of anhydrous ethylene glycol ether to the system, replace nitrogen three times, add acetylacetone (CAS: 88167-56-0) (15 mmol) under nitrogen, reflux at 110 ° C for 24 hours under nitrogen protection, cool, filter, wash with alcohol, dry at 50 ° C for at least 10 hours, use dichloromethane as solvent, and use neutral alumina column chromatography. The filtrate is concentrated and the solid is precipitated to finally obtain the organic light-emitting material Z-640 (3.28 g, yield 59%).

[0208] HPLC purity was greater than 99.5%.

[0209] Mass spectrum: test value is 1112.42.

[0210] Elemental Analysis:

[0211] Calculated values: C: 68.72; H: 3.84; Cl: 3.38; N: 2.67; O: 3.05.

[0212] The test values ​​are C:68.73; H:3.83; Cl:3.39; N:2.63; O:3.06.

[0213] 1H NMR (400MHz, Chloroform-d) δ8.69 (d, 2H), 8.09-8.01 (m, 4H), 7.69-7.58 (m, 4H), 7.47-7.42 (m, 2H), 7.44-7.32 (m, 10H), 7.32-7.24 (m, 6H), 5.86 (d, 1H), 2.36 (d, 6H), 2.14 (d, 3H), 2.02 (d, 3H), 1.93 (s, 6H). Example 5

[0214]

[0215] In the first step, under nitrogen protection, intermediate 9 (180 mmol) and anhydrous potassium carbonate (540 mmol) were put into the reaction system, 1000 ml toluene, 500 ml anhydrous ethanol, 500 ml purified water were added, Pd (PPh3) 4 (1.5 mmol) was added under nitrogen protection, 3, 4-dimethylphenylboronic acid (CAS: 55499-43-9) (180 mmol) was added in three batches every 1 hour, after the addition was completed, refluxed at 100 ° C for 24 h under nitrogen protection, and then cooled to 24 ° C. After the reaction was cooled, it was extracted with ethyl acetate, washed three times with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The crude product was column chromatographed (200-300 mesh, 450 g) to remove impurities, the developing agent EA: PE = 1: 10, the receiving liquid was vortexed until no liquid flowed out, and vacuum dried to obtain the compound shown in formula II-821 (47.45 g, yield 62%).

[0216] HPLC purity was greater than 99.5%.

[0217] Mass spectrum: Test value is 425.36.

[0218] In the second step, under the protection of nitrogen, weigh the ligand II-821 (25mmol) and IrC13·3H2O (10mmol) and put them into the reaction system, add a mixed solution of 180ml of ethylene glycol ethyl ether and 60ml of pure water, reflux at 110°C for 24h under nitrogen protection, and then cool to room temperature. A precipitate is precipitated, and the precipitate is filtered, washed with water, anhydrous ethanol, and petroleum ether in turn, and dried at 50°C for at least 10h to obtain the bridged ligand III-821 (4.52g, yield 42%).

[0219] The third step is to weigh the bridging ligand III-821 (5 mmol), add anhydrous potassium carbonate (50 mmol), and then add 144 ml of anhydrous ethylene glycol ether to the system, replace nitrogen three times, add 3,7-diethylnonane-4,6-dione (CAS: 872802-98-7) (15 mmol) under nitrogen, reflux at 110 ° C for 24 hours under nitrogen protection, cool, filter, wash with alcohol, dry at 50 ° C for at least 10 hours, use dichloromethane as solvent, use neutral alumina column chromatography, concentrate the filtrate and precipitate the solid, and finally obtain the organic phosphorescent material formula Z-821 (3.32 g, yield 53%).

[0220] HPLC purity was greater than 99.5%.

[0221] Mass spectrum: Test value is 1252.60.

[0222] Elemental Analysis:

[0223] Calculated values ​​are C: 71.92; H: 5.39; N: 2.24; O: 5.11.

[0224] The test values ​​are C:71.91; H:5.42; N:2.25; O:5.09.

[0225] 1H NMR(400MHz,Chloroform-d)δ8.71-8.02(m,6H),7.69-7.58(m,4H),7.47-7.32(m,12H),7.30-7.20(m,4H),5. 81(d,1H),2.76(d,1H),2.62(d,1H),2.38(s,6H),2.29(d,6H),1.93(s,6H),1.67-1.47(m,8H),0.89(t,12H).

[0226] Example 6

[0227]

[0228] In the first step, under nitrogen protection, intermediate 9 (180 mmol) and anhydrous potassium carbonate (540 mmol) were put into the reaction system, 1000 ml toluene, 500 ml anhydrous ethanol, 500 ml purified water were added, Pd(PPh3)4 (1.5 mmol) was added under nitrogen protection, 3,5-dimethylphenylboronic acid (CAS: 1172975-69-8) (180 mmol) was added in three batches every 1 hour, after the addition was completed, refluxed at 100 ° C for 24 h under nitrogen protection, and then cooled to 24 ° C. After the reaction was cooled, it was extracted with ethyl acetate, washed three times with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The crude product was column chromatographed (200-300 mesh, 450 g) to remove impurities, the developing agent EA: PE = 1: 10, the receiving liquid was vortexed until no liquid flowed out, and vacuum dried to obtain the compound shown in formula II-1002 (33.67 g, yield 44%).

[0229] Its HPLC purity is greater than 99.5%.

[0230] Mass spectrum: Test value is 425.29.

[0231] In the second step, under nitrogen protection system, weigh ligand II-1002 (25mmol), IrC13·3H2O (10mmo1) and put into the reaction system, add a mixed solution of 180ml ethylene glycol ethyl ether and 60ml pure water, reflux at 110°C for 24h under nitrogen protection, and then cool to room temperature. A precipitate is precipitated, and the precipitate is filtered, washed with water, anhydrous ethanol and petroleum ether in turn, and dried at 50°C for at least 10h to obtain the bridged ligand III-1002 (5.92g, yield 55%).

[0232] The third step is to weigh the bridging ligand III-1002 (5 mmol), add anhydrous potassium carbonate (50 mmol), and then add 144 ml of anhydrous ethylene glycol ether to the system, replace nitrogen three times, add 3,7-diethyl-5-fluoro-4,6-nonanedione (CAS: 2560616-03-5) (15 mmol) under nitrogen, reflux at 110 ° C for 24 hours under nitrogen protection, cool, filter, wash with alcohol, dry at 50 ° C for at least 10 hours, use dichloromethane as solvent, and use neutral alumina column chromatography. The filtrate is concentrated and the solid is precipitated to finally obtain the organic phosphorescent material Z-1002 (3.87 g, yield 61%).

[0233] HPLC purity was greater than 99.5%.

[0234] Mass spectrum: test value is 1270.69.

[0235] Elemental Analysis:

[0236] Calculated values ​​are C:70.90; H:5.24; F:1.50; N:2.20; O:5.04.

[0237] The test values ​​are C:70.91; H:5.23; F:1.48; N:2.23; O:5.05.

[0238] 1 H NMR(400MHz,Chloroform-d)δ8.71(d,2H),8.08(dd,2H),8.00(dd,2H),7.66(dd,2H),7.64-7.58(m,2H),7.47-7.32(m,8H),7.32-7.24(m ,6H),7.13-7.09(m,2H),2.97(d,2H),2.40(s,12H),1.93(s,6H),1.6 7-1.60(m,4H),1.63-1.56(m,2H),1.59-1.48(m,2H),0.90(td,12H).

[0239] In the embodiments of the present invention, the preparation methods of the metal iridium complexes represented by other formulas Z-1 to Z-1290 are basically the same as the methods in the above embodiments, and only the corresponding raw materials need to be replaced, which will not be described in detail here. For example, when preparing the metal iridium complex formula Z-730, the compound formula II-94 can be replaced with the compound formula II-730 according to the method for preparing the metal iridium complex formula Z-94, and other conditions can be adjusted accordingly.

[0240] In this example, the mass spectrometry results of some other preparation examples of metal iridium complexes are shown in Table 1.

[0241] Table 1

[0242] Compound Molecular formula Mass spectrometry measurements Type Z-28 <![CDATA[C 77 H 45 D4IrN4O4]]> 1290.46 Type Z-94 <![CDATA[C 54 H 41 IrN2O4]]> 974.38 Type Z-156 <![CDATA[C 72 H 77 D8Ge2IrN2O2Se2]]> 1518.56 Type Z-190 <![CDATA[C 68 H 44 D6IrN3O4]]> 1171.50 Type Z-230 <![CDATA[C 81 H 76 F3IrN2O4]]> 1390.61 Type Z-275 <![CDATA[C 62 H 41 IrN2O4]]> 1070.47 Type Z-306 <![CDATA[C 62 H 61 IrN2O2Si2]]> 1114.58 Type Z-421 <![CDATA[C 67 H 67 IrN2O4]]> 1156.69 Type Z-456 <![CDATA[C 77 H 51 IrN2O6]]> 1292.52 Type Z-512 <h2 style=";text-align:left;direction:ltr"><![CDATA[C <h2 style=";text-align:left;direction:ltr"> 69 <h2 style=";text-align:left;direction:ltr"> H<h2 style=";text-align:left;direction:ltr"> 71 <h2 style=";text-align:left;direction:ltr"> IrN2O2S2<h2 style=";text-align:left;direction:ltr"> 1216.56 Type Z-640 <![CDATA[C 65 H 47 IrN2O4]]> 1112.48 Type Z-730 <![CDATA[C 63 H 37 D6IrN2O4]]> 1090.55 Type Z-798 <![CDATA[C 61 H 31 D 24 IrN2O4]]> 1096.64 Type Z-821 <![CDATA[C 75 H 67 IrN2O4]]> 1252.59 Type Z-888 <![CDATA[C 77 H 95 IrN2O2Se2Si2]]> 1488.62 Type Z-903 <![CDATA[C 53 H 32 D7IrN2O4]]> 967.40 Type Z-907 <![CDATA[C 53 H 32 D7IrN2O4]]> 967.42 Type Z-989 <![CDATA[C 75 H 62 D 18 F3IrN2O4]]> 1340.82 Type Z-1002 <![CDATA[C 75 H 66 FIrN2O4]]> 1270.59 Type Z-1120 <![CDATA[C 87 H 75 IrN2O4]]> 1404.66

[0243] Device Example 1:

[0244] The metal iridium complex Z-94 prepared in Example 1 is used to prepare an organic electroluminescent device, and the specific method is as follows:

[0245] The coating thickness is The ITO glass substrate was washed in distilled water for 3 times, ultrasonically washed for 30 minutes, and repeatedly washed with distilled water for 3 times, ultrasonically washed for 30 minutes. After the distilled water washing, it was ultrasonically washed in sequence with isopropanol, acetone, methanol and other solvents, dried, and transferred to a plasma cleaning machine. The above ITO glass substrate was washed for 5 minutes and sent to a vapor deposition machine; under vacuum conditions, the standard pressure was set to 1×10 -6 torr, and then CuPc NPB CBP+Iridium Complex Z-94 Alq3 LiF and Al The organic matter layers are formed in this order.

[0246] The CBP+metal iridium complex Z-94 refers to CBP doped with 5% (mass) of metal iridium complex Z-94 for vapor deposition.

[0247] The structural formulas of CuPc, NPB, CBP and Alq3 used in the embodiments of the present invention are as follows:

[0248]

[0249] Other device embodiments:

[0250] Referring to the above method, the metal iridium complex Z-94 was replaced by the metal iridium complexes listed in Table 2 to prepare the corresponding organic electroluminescent devices.

[0251] Device Comparative Example 1-Device Comparative Example 6:

[0252] An organic electroluminescent device was prepared in the same manner as in Device Example 1, except that (btp)2Ir(acac), Comparative Example 2, Comparative Example 3, Comparative Example 4, Comparative Example 5, and Comparative Example 6 were used to replace the doping compound Z-94 in Example 1, respectively. The specific structures are as follows:

[0253]

[0254] The performance of the organic electroluminescent devices obtained from the device examples and the device comparative examples was tested respectively. The specific performance test results are shown in Table 2.

[0255] Table 2 Performance test results

[0256]

[0257]

[0258] As shown in Table 2, under the same current condition, the organic electroluminescent device prepared by the metal iridium complex of the present invention, by selecting a specific heterocyclic ligand to combine, changing the combination of substituents on the ligand, adding branched alkyl, substituted or unsubstituted aryl and substituted or unsubstituted alkyl to generate the metal iridium complex, improves the intermolecular spatial configuration, has a good spatial twisting ability, thereby avoiding carrier migration, and is used as a specific doping material for the light-emitting layer and applied to the organic electroluminescent device, the wavelength of the metal iridium complex can be adjusted, has a lower voltage, and the power efficiency is significantly improved, has the advantages of low evaporation temperature, high light and electrochemical stability, high luminous efficiency, long device life, etc., and the preparation method provided by the embodiment of the invention has a simple process, the prepared product has high purity, and is suitable for industrial production.

[0259] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be 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 will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A metal iridium complex, characterized in that The structure of the metal iridium complex is shown in Formula I: in, R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 , R 11 represents a single substituent or no substituent; R 12 , R 13 and R 14 represents a single substituent or no substituent; R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 and R 11 independently selected from hydrogen, deuterium, halogen, nitro, trimethylsilyl, trimethylgermanium, -CN, substituted or unsubstituted C1-C 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 Alkylamino, substituted or unsubstituted C2-C 60 Alkenyl, substituted or unsubstituted C2-C 60 Alkyne, substituted or unsubstituted C4-C 60 heterocyclic group; and said R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 , R 11 Each independently forms a substituted or unsubstituted C3-C30 aliphatic ring, a substituted or unsubstituted C6-C18 aromatic ring, or a substituted or unsubstituted C4-C18 aromatic heterocyclic ring with the ring in which it is located; R 12 , R 13 and R 14 Independently selected from hydrogen, methyl, propyl, tert-butyl, pentyl, deuterium, -CN, -F, -CF3, dimethylhexyl; X is independently selected from O, Ge, S, Si, Se; Y is independently selected from hydrogen, deuterium, -F, -CN, methyl, ethyl, propyl, phenyl, tert-butylbenzene, and phenyl substituted with cyano.

2. The metal iridium complex according to claim 1, characterized in that R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 and R 11 independently selected from hydrogen, deuterium, thiophene, furan, methyl, ethyl, propyl, tert-butyl, neopentyl, phenyl, deuterated phenyl, cyano-substituted phenyl, tert-butylbenzene, alkyl-substituted phenyl, nitro, trimethylsilyl, trimethylgermanium, -CN, halogen; Y is independently selected from hydrogen, deuterium, -F, -CN, methyl.

3. The metal iridium complex according to claim 1 or 2, characterized in that The hydrogen in the group or the substituent may be deuterated.

4. The metal iridium complex according to claim 1, characterized in that The metal iridium complex is selected from any one of the compounds represented by the following structural formulas:

5. A method for preparing the metal iridium complex as claimed in claim 1, characterized in that: The method specifically comprises the following steps: (1) providing a compound II represented by the following structural formula: (2) reacting the compound II provided in step (1) with iridium trichloride to obtain a compound III represented by the following structural formula: (3) providing a compound IV represented by the following structural formula: (4) reacting the compound IV provided in step (3) with the compound III obtained in step (2) to obtain the metal iridium complex; Among them, R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 , R 11 , R 12 , R 13 and R 14 The same as defined in claim 1.

6. The method for preparing the metal iridium complex according to claim 5, characterized in that: In step (2), the molar ratio of the compound II to the iridium trichloride is (2.2-2.5):1; in the reaction, the solvent used is a mixed solution of ethylene glycol ethyl ether and ultrapure water in a volume ratio of 3:1, the amount of the solvent used is 15-30 times the mass of the iridium trichloride, and the reaction time is 24-30 hours.

7. The method for preparing the metal iridium complex according to claim 5, characterized in that: In step (4), the molar ratio of the compound III to the compound IV is 1:(2.5-8); in the reaction, the base used is anhydrous potassium carbonate or anhydrous sodium carbonate, the solvent is ethylene glycol ethyl ether, the amount of the solvent used is 10-30 times the mass of the compound III, and the reaction time is 10-30 hours.

8. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises the metal iridium complex as claimed in claim 1.

9. The organic electroluminescent device according to claim 8, 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 comprises the metal iridium complex as claimed in claim 1.

10. The organic electroluminescent device according to claim 9, characterized in that: The organic electroluminescent device comprises a light-emitting layer; the light-emitting layer comprises a main material and a doping material, the doping material is the metal iridium complex, and the mixing ratio of the main material to the doping material is 90:10 to 99.5:0.5.

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