Organometallic compound and preparation method and application thereof

Abstract

The invention discloses an organic metal compound as well as a preparation method and application thereof, and relates to the technical field of organic electroluminescence. Functional groups such as benzene and biphenyl are introduced to a dibenzofuran ring main body, and electron withdrawing groups such as cyano or methyl are added to a benzene ring, so that compared with a contrast compound, the compound provided by the invention has the advantages that the molecular configuration is changed, a conjugated system is enlarged, and the electrochemical characteristics of the compound are adjusted; after the obtained organic compound is applied to the organic electroluminescent device, the starting voltage of the device is reduced, the luminous efficiency of the device is improved, and the service life of the device is prolonged.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescence technology, and more specifically to an organometallic compound, its preparation method, and its application. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are a type of device with a sandwich-like structure, consisting of positive and negative electrode layers and an organic functional material layer sandwiched between the electrode layers. When a voltage is applied to the electrodes of an OLED device, positive charges are injected from the positive electrode and negative charges are injected from the negative electrode. Under the influence of an electric field, the positive and negative charges migrate, meet, and recombine in the organic layer to emit light.

[0003] Due to its advantages such as high brightness, fast response, wide viewing angle, simple manufacturing process, and flexibility, OLED devices have attracted much attention in the fields of new display technology and new lighting technology. Currently, OLED devices are widely used in display panels of new lighting fixtures, smartphones, and tablets, and will further expand into large-size display products such as televisions. It is a rapidly developing new display technology with high technical requirements.

[0004] The research on high-efficiency phosphorescent organic light-emitting devices has provided a significant impetus for the development of the flat panel and portable display industries. Therefore, how to develop a high-performance phosphorescent material that enables organic light-emitting devices to possess comprehensive characteristics such as high efficiency, long lifespan, and low voltage is a technical problem that urgently needs to be solved by researchers in this field. Summary of the Invention

[0005] In view of this, the present invention provides an organometallic compound, its preparation method and application. When used in organic electroluminescent devices, the organometallic compound reduces the device's start-up voltage and improves the device's luminous efficiency and lifespan.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An organometallic compound with the structure shown in Formula I:

[0008]

[0009] Among them, R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 Each is independently selected from -H, -D, -T, -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, silicon-based, germanium-based, substituted or unsubstituted C2-C. 10Alkyl, substituted or unsubstituted C3-C8 cycloalkyl, substituted or unsubstituted C6-C 20 Any one of aryl, substituted or unsubstituted 4- to 8-membered heterocyclic groups;

[0010] The R 13 R 14 R 15 R 16 Each is independently selected from H, and at least one of the substituents is S1;

[0011] The N1, N2, N3, N4, N5, and N6 are each independently selected from H, and at least three of them are simultaneously and independently selected from substituted or unsubstituted phenyl groups.

[0012] Preferably, ligand L A Selected from the following structure L A -1~L A Any of the following: -96

[0013]

[0014]

[0015]

[0016]

[0017] Preferably, ligand L B Selected from the following structure L B -1~L B Any one of -90:

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024] Preferably, Formula I is selected from any one of the following structures L-1 to L-900:

[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] Another object of the present invention is to provide a method for preparing the above-mentioned organometallic compounds, the synthetic route of which is as follows:

[0076]

[0077] The substituents in the above formulas are the same as those in the above organometallic compounds;

[0078] The specific steps are as follows:

[0079] Step 1: Add raw material LA, iridium trichloride trihydrate, ethylene glycol ethyl ether and water under nitrogen conditions, react at 120°C for 48 hours, filter, wash with ethanol and petroleum ether, and dry to obtain intermediate L-A1;

[0080] Step 2: Under nitrogen conditions, add intermediate L-A1, silver trifluoromethanesulfonate, isopropanol and dichloromethane, react at 25°C for 48 hours, pass through a silica gel funnel, and wash with dichloromethane until no product is produced. Combine the organic phases and spin dry to obtain intermediate L-A2.

[0081] Step 3: Under nitrogen atmosphere, add intermediate L-A2, LB, and ethanol. React at 90°C for 48 hours, then filter and column chromatography to obtain product L, which is the organometallic compound.

[0082] Another object of the present invention is to provide the application of the above-mentioned organometallic compounds in organic electroluminescent devices.

[0083] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects:

[0084] The organic electroluminescent device provided by this invention uses doped materials with specific structures. By introducing functional groups such as benzene and biphenyl onto the dibenzofuran ring host, and adding electron-withdrawing groups such as cyano or methyl groups onto the benzene ring, the compound of this invention, compared with the comparative compound, changes the molecular configuration, increases the conjugated system, and adjusts the electrochemical properties of the compound. As a result, when the organic compound is used in an organic electroluminescent device, the starting voltage of the device is reduced, and the luminous efficiency and lifetime of the device are improved. Attached Figure Description

[0085] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0086] Figure 1 This is the hydrogen NMR spectrum of L-345. Detailed Implementation

[0087] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0088] Example 1: Preparation of organometallic compound L-21

[0089] The specific operation and process route are as follows:

[0090]

[0091] Step 1: Under nitrogen atmosphere, weigh out raw material A-21 (CAS: 889109-65-3) (355 mmol), pinacol diborate (355 mmol), 1,4-dioxane (2 L), and potassium acetate (0.88 mol), and add them sequentially to the reaction system. Replace the nitrogen atmosphere twice. Under nitrogen atmosphere, add tris(dibenzylacetone)dipalladium (7.01 mmol) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (28.4 mmol). React at 80 °C for 24 h. After the reaction is stopped, cool the system to room temperature, pass the system through a silica gel funnel, evaporate to dryness, and perform column chromatography to obtain intermediate B-21 (88.7 g, yield 76%).

[0092]

[0093] Step 2: Under nitrogen atmosphere, weigh B-21 (243 mmol), C-21 (243 mmol CAS162720-29-0), potassium carbonate (729 mmol), toluene (1600 ml), ethanol (800 ml), and water (800 ml). Replace the nitrogen atmosphere twice and add tetraphenylphosphine palladium (4.86 mmol) under nitrogen atmosphere. React at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and precipitate by column chromatography to obtain intermediate D-21 (69.8 g, yield 70%).

[0094]

[0095] Step 3: Under nitrogen atmosphere, weigh out D-21 (153 mmol), phenylboronic acid (306 mmol), potassium carbonate (459 mmol), toluene (1380 ml), ethanol (690 ml), and water (690 ml). Replace the nitrogen atmosphere twice, then add tetraphenylphosphine palladium (3.06 mmol) under nitrogen atmosphere. React at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and perform column chromatography to obtain intermediate E-21 (41.8 g, yield 61%).

[0096]

[0097] Step 4: Under nitrogen atmosphere, weigh E-21 (89 mmol), pinacol diborate (89 mmol), 1,4-dioxane (800 ml), and potassium acetate (222.5 mmol) and add them sequentially to the reaction system. Replace the nitrogen atmosphere twice. Under nitrogen atmosphere, add tris(dibenzylacetone)dipalladium (1.78 mmol) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (7.12 mmol). React at 80 °C for 24 h. After the reaction is complete, cool the system to room temperature, pass the system through a silica gel funnel, evaporate to dryness, and perform column chromatography to obtain intermediate F-21 (31.3 g, yield 65%).

[0098]

[0099] Step 5: Under nitrogen atmosphere, weigh out F-21 (55 mmol), phenylboronic acid (55 mmol), potassium carbonate (550 mmol), toluene (600 ml), ethanol (300 ml), and water (300 ml). Replace the nitrogen atmosphere twice, then add tetraphenylphosphine palladium (1.1 mmol) under nitrogen atmosphere and react at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and perform column chromatography to obtain intermediate G-21 (20.9 g, yield 61%).

[0100]

[0101] Step 6: Under nitrogen atmosphere, weigh out G-21 (33 mmol), H-21 (50 mmol CAS: 1086381-43-2), potassium carbonate (330 mmol), toluene (400 ml), ethanol (200 ml), and water (200 ml). Replace the nitrogen atmosphere twice. Add tetraphenylphosphine palladium (0.6 mmol) under nitrogen atmosphere and react at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and precipitate by column chromatography to obtain intermediate I-21 (13.9 g, yield 70%).

[0103]

[0104] Step 7: Weigh the following raw material J-21 (CAS1622235-49-759.8 mmol), iridium trichloride (27.2 mmol), ethylene glycol ether (200 ml), and water (67 ml) under nitrogen atmosphere. React at 120°C for 48 h. Filter, wash, and dry to obtain intermediate K-21 (12.5 g, 80% yield).

[0105] Step 8: Weigh out the following raw materials under nitrogen atmosphere: K-21 (10.6 mmol), silver trifluoromethanesulfonate (23.3 mmol), dichloromethane (242 ml), and isopropanol (60 ml). React at 25°C for 48 h. Pass the mixture through a silica gel funnel and evaporate to dryness to obtain intermediate M-21 (12 g, 75% yield).

[0106]

[0107] Step 9: Weigh out the starting material M-21 (7.48 mmol), I-21 (14.96 mmol), and 120 ml of ethanol under nitrogen atmosphere, and react at 90°C for 48 h. Filter and column chromatography to obtain the final product L-21 (4.8 g, 58% yield).

[0108] HPLC purity >99%

[0109] Mass spectrometry: Measured value 1125.53

[0110] Elemental analysis: Calculated values: C, 72.57%; H, 5.19%; N, 3.73%; O, 1.42%. Measured values: C,

[0111] 72.58%; H5.20%; N3.75%; O, 1.44%

[0112] Nuclear magnetic field: NMR (400MHz, Chloroform-d) δ 8.69 (d, 1H), 8.38 (d, 2H), 8.13-8.02 (m, 4H), 7.84 (d, 2H), 7.69 (dd, 2H), 7.64 (s, 1H), 7.63-7.59(m, 7H), 7.59-7.47(m, 6H), 7.41-7.33(m, 11H), 7.22-7.16(m, 3H), 3.10-3.02(m, 1H), 1.28(d, 6H).

[0113] Example 2: Preparation of organometallic compound L-183

[0114] The specific operation and process route are as follows:

[0115]

[0116] Step 1: Under nitrogen atmosphere, weigh out raw material A-183 (CAS: 889109-65-3) (355 mmol), pinacol diborate (355 mmol), 1,4-dioxane (2 L), and potassium acetate (0.88 mol), and add them sequentially to the reaction system. Replace the nitrogen atmosphere twice. Under nitrogen atmosphere, add tris(dibenzylacetone)dipalladium (7.01 mmol) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (28.4 mmol). React at 80 °C for 24 h. After the reaction is stopped, cool the system to room temperature, pass the system through a silica gel funnel, evaporate to dryness, and perform column chromatography to obtain intermediate B-183 (88.7 g, yield 76%).

[0117]

[0118] Step 2: Under nitrogen atmosphere, weigh B-183 (243 mmol), C-183 (243 mmol CAS162720-29-0), potassium carbonate (729 mmol), toluene (1600 ml), ethanol (800 ml), and water (800 ml). Replace the nitrogen atmosphere twice. Add tetraphenylphosphine palladium (4.86 mmol) under nitrogen atmosphere and react at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and precipitate by column chromatography to obtain intermediate D-183 (69.8 g, yield 70%).

[0119]

[0120] Step 3: Under nitrogen atmosphere, weigh D-183 (153 mmol), phenylboronic acid (306 mmol), potassium carbonate (459 mmol), toluene (1380 ml), ethanol (690 ml), and water (690 ml). Replace the nitrogen atmosphere twice, add tetra-triphenylphosphine palladium (3.06 mmol) under nitrogen atmosphere, and react at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and precipitate by column chromatography to obtain intermediate E-183 (41.8 g, yield 61%).

[0121]

[0122] Step 4: Under nitrogen atmosphere, weigh E-183 (89 mmol), pinacol diborate (89 mmol), 1,4-dioxane (800 ml), and potassium acetate (222.5 mmol) and add them sequentially to the reaction system. Replace the nitrogen atmosphere twice. Under nitrogen atmosphere, add tris(dibenzylacetone)dipalladium (1.78 mmol) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (7.12 mmol). React at 80 °C for 24 h. After the reaction is complete, cool the system to room temperature, pass the system through a silica gel funnel, evaporate to dryness, and perform column chromatography to obtain intermediate F-183 (31.3 g, yield 65%).

[0123]

[0124] Step 5: Under nitrogen conditions, weigh out F-183 (55 mmol), phenylboronic acid (55 mmol), potassium carbonate (550 mmol), toluene (600 ml), ethanol (300 ml), and water (300 ml). Replace the nitrogen twice, add tetrakis(triphenylphosphine)palladium (1.1 mmol) under nitrogen conditions, and react at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and precipitate by column chromatography to obtain intermediate G-183 (20.9 g, yield 63%).

[0125]

[0126] Step 6: Under nitrogen atmosphere, weigh out G-183 (33 mmol), H-183 (50 mmol CAS: 109-04-6), potassium carbonate (330 mmol), toluene (400 ml), ethanol (200 ml), and water (200 ml). Replace the nitrogen atmosphere twice. Add tetraphenylphosphine palladium (0.6 mmol) under nitrogen atmosphere and react at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and precipitate by column chromatography to obtain intermediate I-183 (13.9 g, yield 70%).

[0127]

[0128] Step 7: Weigh the following raw material J-183 (CAS27012-22-296.3 mmol), iridium trichloride (32.1 mmol), ethylene glycol ether (218 ml), and water (71 ml) under nitrogen atmosphere. React at 120°C for 48 h. Filter, wash, and dry to obtain intermediate K-183 (13.8 g, 82% yield).

[0129] Step 8: Weigh out the following raw materials under nitrogen atmosphere: K-183 (11.1 mmol), silver trifluoromethanesulfonate (24.4 mmol), 238 ml dichloromethane, and 60 ml isopropanol. React at 25°C for 48 h. Pass through a silica gel funnel and evaporate to dryness to obtain intermediate M-183 (12.5 g, 78% yield).

[0130]

[0131] Step 9: Weigh out the starting material M-183 (7.53 mmol), I-183 (15.06 mmol), and 120 ml of ethanol under nitrogen atmosphere, and react at 90°C for 48 h. Filter and column chromatography to obtain the final product L-183 (4.69 g, 60% yield).

[0132] HPLC purity >99%

[0133] Mass spectrometry: Measured value 1077.54

[0134] Elemental analysis: Calculated values: C, 72.47%; H, 4.30%; N, 3.90%; O, 1.49%. Measured values: C,

[0135] 72.48%; H4.32%; N3.91%; O, 1.51%

[0136] Nuclear magnetic NMR (400MHz, Chloroform-d) δ8.71 (dd, 1H), 8.47 (d, 2H), 8.11 (dd, 2H), 8.07-8.01 (m, 2H), 7. 90 (dd, 1H), 7.75 (td, 1H), 7.71-7.31 (m, 28H), 7.25 (ddd, 1H), 7.19 (td, 2H), 2.27-2.23 (m, 6H).

[0137] Example 3: Preparation of organometallic compound L-345

[0138] The specific operation and process route are as follows:

[0139]

[0140] Step 1: Under nitrogen atmosphere, weigh out raw material A-345 (CAS: 889109-65-3) (355 mmol), pinacol diborate (355 mmol), 1,4-dioxane (2 L), and potassium acetate (0.88 mol), and add them sequentially to the reaction system. Replace the nitrogen atmosphere twice. Under nitrogen atmosphere, add tris(dibenzylacetone)dipalladium (7.01 mmol) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (28.4 mmol). React at 80 °C for 24 h. After the reaction is complete, cool the system to room temperature, pass the system through a silica gel funnel, evaporate to dryness, and perform column chromatography to obtain intermediate B-345 (88.7 g, yield 76%).

[0141]

[0142] Step 2: Under nitrogen atmosphere, weigh out B-345 (243 mmol), C-345 (243 mmol CAS162720-29-0), potassium carbonate (729 mmol), toluene (1600 ml), ethanol (800 ml), and water (800 ml). Replace the nitrogen atmosphere twice, then add tetraphenylphosphine palladium (4.86 mmol) under nitrogen atmosphere. React at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and perform column chromatography to obtain intermediate D-345 (69.8 g, yield 70%).

[0143]

[0144] Step 3: Under nitrogen atmosphere, weigh out D-345 (153 mmol), phenylboronic acid (306 mmol), potassium carbonate (459 mmol), toluene (1380 ml), ethanol (690 ml), and water (690 ml). Replace the nitrogen atmosphere twice, then add tetraphenylphosphine palladium (3.06 mmol) under nitrogen atmosphere. React at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and perform column chromatography to obtain intermediate E-345 (41.8 g, yield 61%).

[0145]

[0146] Step 4: Under nitrogen atmosphere, weigh E-345 (89 mmol), pinacol diborate (89 mmol), 1,4-dioxane (800 ml), and potassium acetate (222.5 mmol) and add them sequentially to the reaction system. Replace the nitrogen atmosphere twice. Under nitrogen atmosphere, add tris(dibenzylacetone)dipalladium (1.78 mmol) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (7.12 mmol). React at 80 °C for 24 h. After the reaction is complete, cool the system to room temperature, pass the system through a silica gel funnel, evaporate to dryness, and perform column chromatography to obtain intermediate F-345 (31.3 g, yield 65%).

[0147]

[0148] Step 5: Under nitrogen atmosphere, weigh out F-345 (55 mmol), phenylboronic acid (55 mmol), potassium carbonate (550 mmol), toluene (600 ml), ethanol (300 ml), and water (300 ml). Replace the nitrogen atmosphere twice, then add tetraphenylphosphine palladium (1.1 mmol) under nitrogen atmosphere and react at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and perform column chromatography to obtain intermediate G-345 (20.9 g, yield 63%).

[0149]

[0150] Step 6: Under nitrogen atmosphere, weigh out G-345 (33 mmol), H-345 (50 mmol CAS: 1086381-43-2), potassium carbonate (330 mmol), toluene (400 ml), ethanol (200 ml), and water (200 ml). Replace the nitrogen atmosphere twice. Add tetra-triphenylphosphine palladium (0.6 mmol) under nitrogen atmosphere and react at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and precipitate by column chromatography to obtain intermediate I-345 (13.9 g, yield 70%).

[0152]

[0153] Step 7: Weigh the following raw material J-345 (CAS1008-89-596.6 mmol), iridium trichloride (32.2 mmol), ethylene glycol ether (220 ml), and water (73 ml) under nitrogen atmosphere. React at 120°C for 48 h. Filter, wash, and dry to obtain intermediate K-345 (14.1 g, 82% yield).

[0154] Step 8: Weigh out the following raw materials under nitrogen atmosphere: K-345 (11.2 mmol), silver trifluoromethanesulfonate (24.6 mmol), dichloromethane (240 ml), and isopropanol (60 ml). React at 25°C for 48 h. Pass through a silica gel funnel and evaporate to dryness to obtain intermediate M-345 (12.9 g, yield 81%).

[0155]

[0156] Step 9: Weigh out the starting material M-345 (7.80 mmol), I-345 (15.60 mmol), and 120 ml of ethanol under nitrogen atmosphere, and react at 90°C for 48 h. Filter and column chromatography to obtain the final product L-345 (5.19 g, 61% yield).

[0157] HPLC purity >99%

[0158] Mass spectrometry: Measured value 1091.55

[0159] Elemental analysis: Calculated values: C, 72.96%; H, 4.68%; N, 3.75%; O, 1.43%. Measured values: C,

[0160] 72.99%; H4.69%; N3.76%; O, 1.46%

[0161] Nuclear magnetic NMR (400MHz, Chloroform-d) δ8.69 (d, 1H), 8.62 (dd, 2H), 8.12-8.04 (m, 3H), 8.03 (d, 1H), 7.83 (dd, 2H), 7.75-7.67 (m, 2H), 7.66-7.53 (m, 1 1H), 7.50(d, 1H), 7.48-7.43(m, 2H), 7.43-7.39(m, 2H), 7.39-7.30(m, 9H), 7.25(ddd, 2H), 7.22-7.16(m, 3H), 3.10-3.02(m, 1H), 1.28(d, 6H).

[0162] The hydrogen NMR spectrum of L-345 is as follows: Figure 1 As shown.

[0163] Example 4: Preparation of organometallic compound L-507

[0164] The specific operation and process route are as follows:

[0165]

[0166] Step 1: Under nitrogen atmosphere, weigh out raw material A-507 (CAS: 889109-65-3) (355 mmol), pinacol diborate (355 mmol), 1,4-dioxane (2 L), and potassium acetate (0.88 mol), and add them sequentially to the reaction system. Replace the nitrogen atmosphere twice. Under nitrogen atmosphere, add tris(dibenzylacetone)dipalladium (7.01 mmol) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (28.4 mmol). React at 80 °C for 24 h. After the reaction is stopped, cool the system to room temperature, pass the system through a silica gel funnel, evaporate to dryness, and perform column chromatography to obtain intermediate B-507 (88.7 g, yield 76%).

[0167]

[0168] Step 2: Under nitrogen atmosphere, weigh out B-507 (243 mmol), C-507 (243 mmol CAS162720-29-0), potassium carbonate (729 mmol), toluene (1600 ml), ethanol (800 ml), and water (800 ml). Replace the nitrogen atmosphere twice, then add tetraphenylphosphine palladium (4.86 mmol) under nitrogen atmosphere. React at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and perform column chromatography to obtain intermediate D-507 (69.8 g, yield 70%).

[0169]

[0170] Step 3: Under nitrogen atmosphere, weigh out D-507 (153 mmol), phenylboronic acid (306 mmol), potassium carbonate (459 mmol), toluene (1380 ml), ethanol (690 ml), and water (690 ml). Replace the nitrogen atmosphere twice, then add tetraphenylphosphine palladium (3.06 mmol) under nitrogen atmosphere. React at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and perform column chromatography to obtain intermediate E-507 (41.8 g, yield 61%).

[0171]

[0172] Step 4: Under nitrogen atmosphere, weigh E-507 (89 mmol), pinacol diborate (89 mmol), 1,4-dioxane (800 ml), and potassium acetate (222.5 mmol) and add them sequentially to the reaction system. Replace the nitrogen atmosphere twice. Then, under nitrogen atmosphere, add tris(dibenzylacetone)dipalladium (1.78 mmol) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (7.12 mmol). React at 80 °C for 24 h. After the reaction is complete, cool the system to room temperature, pass the system through a silica gel funnel, evaporate to dryness, and perform column chromatography to obtain intermediate F-507 (31.3 g, yield 65%).

[0173]

[0174] Step 5: Under nitrogen atmosphere, weigh out 55 mmol of F-507, 55 mmol of phenylboronic acid, 550 mmol of potassium carbonate, 600 ml of toluene, 300 ml of ethanol, and 300 ml of water. Replace the nitrogen atmosphere twice, then add 1.1 mmol of tetraphenylphosphine palladium under nitrogen atmosphere and react at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and precipitate by column chromatography to obtain intermediate G-507 (20.9 g, yield 63%).

[0175]

[0176] Step 6: Under nitrogen atmosphere, weigh out G-507 (33 mmol), H-507 (50 mmol CAS: 1086381-43-2), potassium carbonate (330 mmol), toluene (400 ml), ethanol (200 ml), and water (200 ml). Replace the nitrogen atmosphere twice. Add tetraphenylphosphine palladium (0.6 mmol) under nitrogen atmosphere and react at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and precipitate by column chromatography to obtain intermediate I-507 (13.9 g, yield 70%).

[0177]

[0178] Step 7: Weigh the following raw materials: J-507 (CAS 701261-35-0490mmol), K-507 (CAS 53939-30-3490mmol), potassium carbonate (1.4mol), toluene (500ml), and ethanol (250ml). React at 70°C for 8 hours. Dry column chromatography yields intermediate M-507 (63g, 70% yield).

[0179]

[0180] Step 8: Weigh out the following raw materials: M-507 (342 mmol), N-507 (CAS 5720-05-8342 mmol), potassium carbonate (1.02 mol), toluene (630 ml), ethanol (315 ml), and water (315 ml). React at 90°C for 12 h. Dry by rotary evaporation and column chromatography to obtain intermediate O-507 (53 g, 65% yield).

[0181] Step 9: Weigh out the starting material O-507 (221 mmol), potassium hydroxide (442 mmol), and dimethyl sulfoxide (280 ml), and react at 90°C for 48 h. Separately evaporate to dryness, and precipitate by column chromatography to obtain intermediate P-507 (27.5 g, yield 50.9%).

[0182]

[0183] Step 10: Weigh the following raw materials under nitrogen atmosphere: P-507, iridium trichloride (50.3 mmol), ethylene glycol ethyl ether (514 ml), and water (171 ml). React at 120°C for 48 h. Filter, wash, and dry to obtain intermediate Q-507 (22.2 g, 60% yield).

[0184] Step 11: Weigh out the following raw materials under nitrogen atmosphere: Q-507 (15.3 mmol), silver trifluoromethanesulfonate (33.8 mmol), dichloromethane (440 ml), and isopropanol (89 ml). React at 25°C for 48 h. Pass the mixture through a silica gel funnel and evaporate to dryness to obtain intermediate R-507 (17.5 g, 60% yield).

[0185]

[0186] Step 12: Weigh out raw materials R-507 (6.34 mmol), I-507 (12.68 mmol), and 120 ml of ethanol under nitrogen atmosphere, and react at 90°C for 48 h. Filter and column chromatography to obtain the final product L-507 (4.74 g, 59% yield).

[0187] HPLC purity >99%

[0188] Mass spectrometry: Measured value 1269.70

[0189] Elemental analysis: Calculated values: C, 73.78%; H, 6.51%; N, 3.31%; O, 1.26%. Measured values: C,

[0190] 73.80%; H6.52%; N3.33%; O, 1.28%

[0191] Nuclear magnetic field: NMR (400MHz, Chloroform-d) δ 8.69 (d, 1H), 8.25 (d, 2H), 8.08 (d, 1H), 8.04 (dd, 1H), 7.91 (d, 2H), 7.86 (d, 2H), 7.66-7.53 (m, 13 H), 7.49(t, 1H), 7.43-7.39(m, 2H), 7.39-7.32(m, 9H), 7.30(dd, 2H), 7.20(dd, 1H), 3.10-3.02(m, 1H), 1.28(d, 6H), 1.19(s, 18H).

[0192] Example 5: Preparation of organometallic compound L-541

[0193] The specific operation and process route are as follows:

[0194]

[0195] Step 1: Under nitrogen atmosphere, weigh out raw material A-541 (CAS: 889109-65-3) (355 mmol), pinacol diborate (355 mmol), 1,4-dioxane (2 L), and potassium acetate (0.88 mol), and add them sequentially to the reaction system. Replace the nitrogen atmosphere twice. Under nitrogen atmosphere, add tris(dibenzylacetone)dipalladium (7.01 mmol) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (28.4 mmol). React at 80 °C for 24 h. After the reaction is stopped, cool the system to room temperature, pass the system through a silica gel funnel, evaporate to dryness, and precipitate by column chromatography to obtain intermediate B-541 (88.7 g, yield 76%).

[0196]

[0197] Step 2: Under nitrogen atmosphere, weigh B-541 (243 mmol), C-541 (243 mmol CAS162720-29-0), potassium carbonate (729 mmol), toluene (1600 ml), ethanol (800 ml), and water (800 ml). Replace the nitrogen atmosphere twice and add tetraphenylphosphine palladium (4.86 mmol) under nitrogen atmosphere. React at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and precipitate by column chromatography to obtain intermediate D-541 (69.8 g, yield 70%).

[0198]

[0199] Step 3: Under nitrogen atmosphere, weigh out D-541 (153 mmol), phenylboronic acid (306 mmol), potassium carbonate (459 mmol), toluene (1380 ml), ethanol (690 ml), and water (690 ml). Replace the nitrogen atmosphere twice, then add tetraphenylphosphine palladium (3.06 mmol) under nitrogen atmosphere. React at 70°C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and perform column chromatography to obtain intermediate E-541 (41.8 g, yield 61%).

[0200]

[0201] Step 4: Under nitrogen atmosphere, weigh E-541 (89 mmol), pinacol diborate (89 mmol), 1,4-dioxane (800 ml), and potassium acetate (222.5 mmol) and add them sequentially to the reaction system. Replace the nitrogen atmosphere twice. Under nitrogen atmosphere, add tris(dibenzylacetone)dipalladium (1.78 mmol) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (7.12 mmol). React at 80 °C for 24 h. After the reaction is complete, cool the system to room temperature, pass the system through a silica gel funnel, evaporate to dryness, and precipitate by column chromatography to obtain intermediate F-541 (31.3 g, yield 65%).

[0202]

[0203] Step 5: Under nitrogen atmosphere, weigh out F-541 (55 mmol), phenylboronic acid (55 mmol), potassium carbonate (550 mmol), toluene (600 ml), ethanol (300 ml), and water (300 ml). Replace the nitrogen atmosphere twice, then add tetraphenylphosphine palladium (1.1 mmol) under nitrogen atmosphere. React at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and perform column chromatography to obtain intermediate G-541 (20.9 g, yield 63%).

[0204]

[0205] Step 6: Under nitrogen atmosphere, weigh out G-541 (33 mmol), H-541 (50 mmol CAS: 1086381-43-2), potassium carbonate (330 mmol), toluene (400 ml), ethanol (200 ml), and water (200 ml). Replace the nitrogen atmosphere twice and add tetraphenylphosphine palladium (0.6 mmol) under nitrogen atmosphere. React at 70 °C for 24 h. After the reaction is complete, cool to room temperature, separate the ethyl acetate, evaporate to dryness, and precipitate by column chromatography to obtain intermediate I-541 (13.9 g, yield 70%).

[0206]

[0207] Step 7: Weigh J-541 (CAS27012-22-273.2 mmol) under nitrogen atmosphere. Add 123 ml of dimethyl sulfoxide and 146 mmol of sodium hydroxide, and react at 90°C for 48 h. Separately evaporate to dryness through a funnel to obtain intermediate K-541 (17 g, 85% yield).

[0208] Step 8: Weigh out the following raw materials under nitrogen atmosphere: K-541 (60.2 mmol), iridium trichloride (27.4 mmol), ethylene glycol ethyl ether (192 ml), and water (64 ml). React at 120°C for 48 h. Filter, wash, and dry to obtain intermediate M-541 (16.9 g, 78% yield).

[0209] Step 9: Weigh out the following raw materials under nitrogen atmosphere: M-541 (10.1 mmol), silver trifluoromethanesulfonate (22.4 mmol), dichloromethane (320 ml), and isopropanol (59 ml). React at 25°C for 48 h. Pass the mixture through a silica gel funnel and evaporate to dryness to obtain intermediate N-541 (14.1 g, 68% yield).

[0210]

[0211] Step 10: Weigh out the starting material N-541 (5.87 mmol), I-541 (11.74 mmol), and 120 ml of ethanol under nitrogen atmosphere, and react at 90°C for 48 h. Filter and column chromatography to obtain the final product L-541 (5.21 g, 66% yield).

[0212] HPLC purity >99%

[0213] Mass spectrometry: Measured value 1345.82

[0214] Elemental analysis: Calculated values: C, 74.97%; H, 6.44%; N, 3.12%; O, 1.19%. Measured values: C,

[0215] 74.98%; H6.46%; N3.13%; O, 1.20%

[0216] Nuclear magnetic field: NMR (400MHz, Chloroform-d) δ8.69 (d, 1H), 8.31 (s, 2H), 8.09-7.98 (m, 4H), 7.64-7.48 (m, 16H), 7. 48-7.42(m, 4H), 7.42-7.35(m, 9H), 7.35-7.25(m, 6H), 7.20(dd, 1H), 3.09-2.94(m, 1H), 1.28(d, 6H).

[0217] The synthesis methods of other organometallic iridium complexes L-30, L-84, L-92, L-123, L-134, L-192, L-354, L-487, L-524, and L-567 are the same as those in the above examples, and will not be repeated here. The molecular formulas and mass spectra of the synthesized organometallic iridium complexes are shown in Table 1 below.

[0218] Table 1

[0219]

[0220]

[0221] Device Examples

[0222] Device Example 1: Fabrication of an organic electroluminescent device using an organometallic compound of formula L-21

[0223] The coating thickness is The ITO glass substrate was washed twice in distilled water and ultrasonically cleaned for 30 minutes. After the distilled water cleaning was completed, it was ultrasonically cleaned in sequence with solvents such as isopropanol, acetone, and methanol, and then dried. It was then transferred to a plasma cleaning machine and cleaned for 5 minutes before being sent to a vapor deposition machine.

[0224] First, the thickness of the ITO (anode) vapor deposit is... 4,4',4”-tris[2-naphthylphenylamino]triphenylamine ("2-TNATA") was used as the hole injection layer, and then a thickness of [missing information] was deposited on the hole injection layer. N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB) is used as the hole transport layer, followed by a evaporation deposition of a thickness of [missing information]. The light-emitting layer consists of a host material of 4,4'-N,N'-biphenyldicarbazole ("CBP") and a dopant compound of formula L-2190 in a weight ratio of 10:10. A thickness of [missing information - likely a specific thickness] is then deposited on the light-emitting layer. ALq3 is used as the electron transport layer, and then a thickness of [missing information] is deposited on the electron transport layer. The electron injection layer material is Liq, and finally a thickness of [thickness missing] is deposited on the electron injection layer. Organic electroluminescent devices can be obtained by using Al as the cathode material.

[0225] The performance and luminescence characteristics of the obtained devices were tested using a KEITHLEY 2400 source measurement unit and a CS-1000 spectroradiometer to evaluate the driving voltage, lifetime, and luminous efficiency.

[0226] Comparative Example 1: An organic electroluminescent device was fabricated using the same method as in Device Example L-21. The structure of the green-doped compound in the emitting layer is as follows:

[0227]

[0228] Comparative Example 2: An organic electroluminescent device was fabricated using the same method as in Device Example L-21. The structure of the green-doped compound in the emitting layer is as follows:

[0229]

[0230] Comparative Example 3: An organic electroluminescent device was fabricated using the same method as in Device Example L-21. The structure of the green doped compound in the emitting layer is as follows.

[0231]

[0232] Comparative Example 4: An organic electroluminescent device was fabricated using the same method as in Device Example L-21. The structure of the green doped compound in the emitting layer is as follows.

[0233]

[0234] Comparative Example 5: An organic electroluminescent device was fabricated using the same method as in Device Example L-21. The structure of the green doped compound in the emitting layer is as follows.

[0235]

[0236] Comparative Example 6: An organic electroluminescent device was fabricated using the same method as in Device Example L-21. The structure of the green doped compound in the emitting layer is as follows.

[0237]

[0238] Comparative Example 7: An organic electroluminescent device was fabricated using the same method as in Device Example L-21. The structure of the green-doped compound in the emitting layer is as follows.

[0239]

[0240] Device Example 2: The method is the same as that in Device Example L-21 above, except that the doping material L-21 is replaced with L-183.

[0241] Device Example 3: The method is the same as that in Device Example L-21 above, except that the doping material L-21 is replaced with L-345.

[0242] Device Example 4: The method is the same as that in Device Example L-21 above, except that the doping material L-21 is replaced with L-507.

[0243] Device Example 5: The method is the same as that in Device Example L-21 above, except that the doping material L-21 is replaced with L-541.

[0244] Device Example 6: The method is the same as that in Device Example L-21 above, except that the doping material L-21 is replaced with L-84.

[0245] Device Example 7: The method is the same as that in Device Example L-21 above, except that the doping material L-21 is replaced with L-192.

[0246] Device Example 8: The method is the same as that in Device Example L-21 above, except that the doping material L-21 is replaced with L-354.

[0247] Device Example 9: The method is the same as that in Device Example J-1 above, except that the doping material L-21 is replaced with L-487.

[0248] Device Example 10: The method is the same as that in Device Example L-21 above, except that the doping material L-21 is replaced with L-567.

[0249] Device Example 11: The method is the same as that in Device Example L-21 above, except that the doping material L-21 is replaced with L-30.

[0250] Device Example 12: The method is the same as that in Device Example L-21 above, except that the doping material L-21 is replaced with L-92.

[0251] Device Example 13: The method is the same as that in Device Example L-21 above, except that the doping material L-21 is replaced with L-123.

[0252] Device Example 14: The method is the same as that in Device Example L-21 above, except that the doping material L-21 is replaced with L-134.

[0253] Device Example 15: The method is the same as that in Device Example L-21 above, except that the doping material L-21 is replaced with L-524.

[0254] The driving voltage, luminous efficiency, and lifetime of the organic electroluminescent devices obtained from the above-mentioned device embodiments and comparative examples were characterized at a brightness of 1000 nits. The test results are shown in Table 2 below.

[0255] Table 2

[0256]

[0257]

[0258] Comparing device data L-183 with Comparative Example 6 shows that adding a phenyl group to the benzene ring increases the size of its conjugated system and, by changing its spatial structure, significantly reduces the driving voltage, resulting in a substantial improvement in luminous efficiency and lifetime. Other comparative examples also demonstrate that adding electron-withdrawing groups to the benzofuran ring makes its structure more stable, thereby greatly improving the device's lifetime.

[0259] 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. An organometallic compound, characterized in that, Its structure is shown in Equation I below: Among them, R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 Each is independently selected from -H, -D, -T, -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, silicon-based, germanium-based, substituted or unsubstituted C2-C. 10 Alkyl, substituted or unsubstituted C3-C8 cycloalkyl, substituted or unsubstituted C6-C 20 Any one of aryl, substituted or unsubstituted 4- to 8-membered heterocyclic groups; The R 13 R 14 R 15 R 16 Each is independently selected from H, and at least one of the substituents is S1; The N1, N2, N3, N4, N5, and N6 are each independently selected from H, and at least three of them are simultaneously and independently selected from substituted or unsubstituted phenyl groups.

2. The organometallic compound according to claim 1, characterized in that the ligand... L A Selected from the following structure L A -1~L A Any of the following: -96 3. The organometallic compound according to claim 1, characterized in that the ligand... L B Selected from the following structure L B -1~L B Any one of -90:

4. The organometallic compound according to claim 1, characterized in that, Formula I is selected from any one of the following structures L-1 to L-900:

5. A method for preparing an organometallic compound as described in any one of claims 1-4, characterized in that, The synthesis route is as follows: The substituents in the above formulas are identical to those in the organometallic compounds of any one of claims 1-4; The specific steps are as follows: Step 1: Add raw material LA, iridium trichloride trihydrate, ethylene glycol ethyl ether and water under nitrogen conditions, react at 120°C for 48 hours, filter, wash with ethanol and petroleum ether, and dry to obtain intermediate L-A1; Step 2: Under nitrogen conditions, add intermediate L-A1, silver trifluoromethanesulfonate, isopropanol and dichloromethane, react at 25°C for 48 hours, pass through a silica gel funnel, and wash with dichloromethane until no product is produced. Combine the organic phases and spin dry to obtain intermediate L-A2. Step 3: Under nitrogen atmosphere, add intermediate L-A2, LB, and ethanol. React at 90°C for 48 hours, then filter and column chromatography to obtain product L, which is the organometallic compound.

6. The application of an organometallic compound as described in claims 1-4 or an organometallic compound prepared by the method of claim 5 in an organic electroluminescent device.

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