Organometallic compounds and organic electroluminescent devices containing same and applications

Abstract

The present invention relates to the field of organic optoelectronic materials and discloses an organometallic compound and an organic electroluminescent device containing the same, as well as its application. The structural formula of the organometallic compound is Ir(L1) m (L2) n In this, m is 2, n is 1, L1 and L2 are both ligands, and [Formula 1] JPEG2025537288000097.jpg49169 The present invention provides organometallic compounds suitable for widespread application to solve the problems of conventional light-emitting devices, such as low efficiency, low stability, and short lifespan.

Description

Detailed Description of the Invention

[0001] [Technical Field] The present invention belongs to the field of organic optoelectronic materials, and in particular to organometallic compounds and organic electroluminescent devices containing same and applications.

[0002] [Background technology] Organic electroluminescence technology is the latest generation of flat panel display technology. Since the discovery of the phosphorescence phenomenon in organic light-emitting devices, it has always attracted people's attention. The luminous efficiency of phosphorescent materials is significantly higher than that of fluorescent materials, and theoretically, 100% luminous efficiency can be achieved. As a result, many scientific research institutions are improving their development capabilities of phosphorescent materials and promoting the industrial development of phosphorescent materials.

[0003] However, in the prior art, when some phosphorescent materials are applied to organic light-emitting devices, they have low efficiency and short lifespan. Therefore, how to provide organic electroluminescent materials with long lifespan, high efficiency and low driving voltage is a problem that those skilled in the art must solve.

[0004] Summary of the Invention In view of the above, the present invention provides organometallic compounds to solve the problems of conventional light-emitting devices, such as low efficiency, low stability and short lifespan.

[0005] To achieve the above object, the first object of the present invention is to provide an organometallic compound, and the following technical solution is adopted:

[0006] An organometallic compound with the structural formula Ir(L1) m (L2) n wherein L1 and L2 are both ligands, and each is

[0007] [ka]

[0008] and Among them, * is a bond, R1 to R8 are each independently selected from -H, -D, -T, -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, a substituted or unsubstituted C2 to C6 alkyl group, and a substituted or unsubstituted C6 to C10 aryl group.

[0009] Ar1 to Ar4 are each independently selected from -H, -D, -T, -F, -CN, -CH3, -CD3, -CT3, -CF3, -CH2F, -CHF2, and a substituted or unsubstituted C2 to C6 alkyl group.

[0010] Furthermore, the alkyl groups in R1 to R8 and Ar1 to Ar4 are each independently one selected from a substituted or unsubstituted straight-chain alkyl group, a substituted or unsubstituted branched-chain alkyl group, and a substituted or unsubstituted cycloalkyl group.

[0011] It should be noted that the organometallic compounds provided by the present invention can adjust the electrochemical properties of the compounds by combining deuterated groups and cyano groups at specific positions of specific heterocyclic ligands, and after the obtained organometallic formulations are used in organic electroluminescent devices, the luminous efficiency of the devices can be improved, the lifetime can be increased, and the driving voltage can be reduced.

[0012] Furthermore, the organometallic compound may have any one of the following structures, but is not limited to these:

[0013] [ka] JPEG2025537288000004.jpg206169JPEG2025537288000005.jpg211169JPEG2025537288000006.jpg231169JPEG2025537288000007.jpg209169JPEG2025537288000008.jpg230169JPEG2025537288000009.jpg204169JPEG2025537288000010.jpg215169JPEG2025537288000011.jpg226169JPEG2025537288000012.jpg202169JPEG2025537288000013.jpg214169JPEG2025537288000014.jpg229169JPEG2025537288000015.jpg209169JPEG2025537288000016.jpg207169JPEG2025537288000017.jpg203169JPEG2025537288000018.jpg213169JPEG2025537288000019.jpg209169JPEG2025537288000020.jpg212169JPEG2025537288000021.jpg215169JPEG2025537288000022.jpg212169JPEG2025537288000023.jpg207169JPEG2025537288000024.jpg218169JPEG2025537288000025.jpg206169JPEG2025537288000026.jpg204169JPEG2025537288000027.jpg218169JPEG2025537288000028.jpg212169JPEG2025537288000029.jpg213169JPEG2025537288000030.jpg213169JPEG2025537288000031.jpg213169JPEG2025537288000032.jpg218169JPEG2025537288000033.jpg156169

[0014] It should be noted that the inventors have conducted tests on all of the above L001 to L880 and found that after using these compounds in organic electroluminescent devices, they can significantly improve the luminous efficiency, extend the service life, and reduce the starting voltage.

[0015] A second object of the present invention is to provide an organic electroluminescent device comprising an organic layer containing the above organometallic compound.

[0016] Specifically, the organometallic compound may be in a single form, or may be present in the organic layer together with other substances.

[0017] Furthermore, the organic electroluminescent device further includes a first electrode and a second electrode, and the organic layer is located between the first electrode and the second electrode, among which: The organic layer includes a light-emitting layer containing the organometallic compound.

[0018] Furthermore, the light-emitting layer contains a host material and a doping material containing the organometallic compound, and the mass ratio of the host material to the doping material is (10 to 99.5):0.5.

[0019] Generally, the organic layer further includes one or more layers selected from the group consisting of a hole injection layer, a hole transport layer, a layer having both hole injection and hole transport functions, an electron blocking layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a layer having both electron transport and electron injection functions, at least one of which functional layers contains the organometallic compound described in the present invention.

[0020] The third object of the present invention is to provide an application of the organic electroluminescent device in the manufacture of an organic light-emitting device, an organic solar cell, an electronic paper, an organic photoreceptor or an organic thin film transistor, and to provide the device with better performance by introducing an organometallic compound into the light-emitting layer.

[0021] Compared with the prior art, the present invention provides an organometallic compound and an organic electroluminescent device containing the same and applications thereof, which have the following excellent effects:

[0022] The organometallic compounds provided by the present invention can adjust the electrochemical properties of the compounds by combining a deuterated group and a cyano group at specific positions of a specific heterocyclic ligand, and after the obtained organometallic compounds are used in organic electroluminescent devices, the luminous efficiency of the devices can be improved, the lifetime can be increased, and the driving voltage can be reduced.

[0023] BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly explain the technical solutions in the embodiments of the present invention or the prior art, the following will briefly describe the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only embodiments of the present invention, and those skilled in the art can also obtain other drawings based on the provided drawings without any creative efforts.

[0024] [Figure 1] Proton nuclear magnetic resonance spectrum of intermediate B-01.

[0025] [Figure 2] Proton nuclear magnetic resonance spectrum of intermediate B-02.

[0026] [Figure 3] Mass spectrum of organometallic compound L005.

[0027] [Figure 4] Mass spectrum of organometallic compound L006.

[0028] [Figure 5] Mass spectrum of organometallic compound L271.

[0029] [Figure 6] Mass spectrum of organometallic compound L567.

[0030] [Mode for Carrying Out the Invention] The technical solutions of the present invention will be described below clearly and completely in accordance with the embodiments of the present invention and the associated drawings, but it is obvious that the described embodiments are only some of the embodiments of the present invention, and not all of the embodiments, and based on the embodiments of the present invention, those skilled in the art can easily obtain all other embodiments without any creative effort, and all of the other embodiments fall within the scope of the present invention.

[0031] The features and performance of the present invention will be described in more detail below with reference to specific examples.

[0032] Compound Example 1 This example provides an organometallic compound L005, namely the compound numbered L005, and the specific synthesis steps are as follows:

[0033] 1) Synthesis of intermediate A-01

[0034] [ka]

[0035] The intermediate 2-bromo-4-methylpyridine (58.13 mmol, 10 g), phenylboronic acid (69.76 mmol, 8.51 g), 150 ml of toluene, 150 ml of water, and 75 ml of absolute ethanol were weighed and added to the reaction system. The reaction mixture was purged with nitrogen gas twice. Under nitrogen gas protection, 0.7 g of Pd(PPh3)4 and 16 g of potassium carbonate were added to the reaction system. The temperature outside the reaction system was set to 90 °C and maintained at 90 °C while stirring for 16 h. The reaction was monitored for completeness by TLC. The reaction system was cooled to 25 °C, the layers were separated, and the organic phase was extracted. The organic phase was dried over anhydrous sodium sulfate and distilled under reduced pressure until no liquid flowed out. The distilled solid was purified by column chromatography (eluent: ethyl acetate:petroleum ether = 1:30) to obtain intermediate A-01 (6.59 g, 67% yield).

[0036] Intermediate A-01 was subjected to the following analytical tests.

[0037] HPLC purity is greater than 99.6% Mass spectrometry gave a calculated value of 169.23 and a found value of 169.20.

[0038] 2) Synthesis of intermediate B-01

[0039] [ka]

[0040] The intermediate 2-pyridineboronic acid (40.68 mmol, 5 g), 6-bromodibenzo[b,d]furan-3-cyano group (33.90 mmol, 9.22 g), 100 ml of toluene, and 100 ml of water were weighed and added to the reaction system. The system was purged with nitrogen gas twice. Under nitrogen gas protection, 0.9 g of Pd(PPh3)4 and 17 g of potassium carbonate were added to the reaction system. The temperature outside the reaction system was set to 90 °C and maintained at 90 °C for 56 h while stirring. The reaction was monitored for completeness by TLC. The reaction system was cooled to room temperature, separated, and the organic phase was extracted and dried over anhydrous sodium sulfate. The organic phase was distilled under reduced pressure until no liquid flowed out. The distilled solid was purified by column chromatography (eluent: ethyl acetate:petroleum ether = 1:3) to obtain intermediate B-01 (6.89 g, yield 75.2%).

[0041] Intermediate B-01 was subjected to the following analytical tests.

[0042] HPLC purity is greater than 99% Mass spectrometry gave a calculated value of 270.29 and a measured value of 270.31.

[0043] The proton nuclear magnetic resonance spectrum is shown in FIG.

[0044] 3) Synthesis of intermediate B-02

[0045] [ka]

[0046] A 2 L reaction flask was purged with nitrogen gas twice, and 360 ml of tetrahydrofuran and intermediate B-01 (22.20 mmol, 6.0 g) were added under nitrogen gas. The reaction mixture was cooled to -80 °C, and 2.5 mol / L n-butyllithium (66.6 mmol, 26.6 ml) was added dropwise. The mixture was allowed to react at low temperature for 6 hours. While maintaining the temperature, 600 ml of heavy water was added dropwise. After maintaining the temperature at low temperature for 30 minutes, the reaction mixture was allowed to naturally return to 25 °C and stirred for 10 hours. 300 ml of ethyl acetate was added, and the mixture was separated. The organic phase was distilled under reduced pressure from the reaction mixture until no liquid flowed out. The distilled solid was purified by column chromatography (eluent: ethyl acetate:petroleum ether = 1:3) to obtain intermediate B-02 (4.86 g, 81% yield).

[0047] Intermediate B-02 was subjected to the following analytical tests.

[0048] HPLC purity is greater than 99% Mass spectrometry gave a calculated value of 271.30 and a found value of 271.28.

[0049] The proton nuclear magnetic resonance spectrum is shown in FIG.

[0050] In the present invention, the positions of some groups in intermediate B-01 are numbered as follows:

[0051] [ka]

[0052] Theoretical calculations indicate that the hydrogen at position 13 of intermediate B-01 has the highest activity and is most likely to be deuterated. As can be seen from the proton nuclear magnetic resonance spectrum data in Figure 1, a single peak with a chemical shift between 7.9 and 8.0 corresponds to hydrogen at position 13, while in the proton nuclear magnetic resonance spectrum in Figure 2, the single peak between 7.9 and 8.0 almost disappears, demonstrating that this position is deuterated.

[0053] 4) Synthesis of intermediate C-01

[0054] [ka]

[0055] Under nitrogen gas protection, intermediate A-01 (29.55 mmol, 5.0 g) and iridium trichloride trihydrate (11.82 mmol, 4.17 g) were weighed and added to the reaction system, and a mixed solution of 150 ml of ethylene glycol ether and 50 ml of purified water was added. Under nitrogen gas protection, the mixture was stirred at 120°C for 48 hours. The temperature of the reaction system was then lowered to 30°C, and a precipitate separated out from the solution. The precipitate was filtered under reduced pressure and washed with water, absolute ethanol, and petroleum ether in that order. The resulting solid was dried to obtain intermediate C-01 (4 g, yield 60%).

[0056] 5) Synthesis of intermediate C-02

[0057] [ka]

[0058] Intermediate C-01 (2.66 mmol, 3 g) was weighed, and silver trifluoromethanesulfonate (5.85 mmol, 1.5 g) was added. 90 ml of dichloromethane and 20 ml of methanol were then added to the system, and the mixture was stirred at 25°C for 56 hours under nitrogen gas protection. The reaction was completed, and the reaction solution was distilled until no more liquid flowed out. The mixture was then subjected to column chromatography (eluent: dichloromethane), and the receiving solution was distilled under reduced pressure until no more solids precipitated, yielding intermediate C-02 (3.85 g, yield 98%).

[0059] 6) Synthesis of organometallic compound L005

[0060] [ka]

[0061] Intermediate C-02 (4.06 mmol, 3 g) was weighed, and Intermediate B-02 (12.18 mmol, 3.31 g) was added. 90 ml of absolute ethanol was then added to the system. Under nitrogen gas protection, the system was refluxed at 90°C for 24 hours. Upon completion of the reaction, the temperature of the reaction system was lowered to 25°C, and the solution was filtered under reduced pressure. The filter cake was rinsed with absolute ethanol and petroleum ether at (60-90)°C in turn and dried under vacuum at 80°C. After drying, the solid was subjected to silica gel column chromatography (eluent: dichloromethane). The filtrate was concentrated to precipitate a solid, yielding organometallic compound L005 (1.59 g, yield 49%).

[0062] The organometallic compound L005 was subjected to the following analytical tests.

[0063] HPLC purity is greater than 99.8% HMOM:-5.38ev, LUMO:-2.60ev, Mass spectrometry gave a calculated value of 789.94 and a measured value of 789.95, as shown in FIG.

[0064] In this embodiment, the application of the above organometallic compounds in the manufacture of organic electroluminescent device products.

[0065] Compound Example 2 This example provides an organometallic compound L006, namely, the compound numbered L006, and the specific synthesis steps are as follows:

[0066] 1) Synthesis of intermediate A-02

[0067] [ka]

[0068] Intermediate A-01 (59.09 mmol, 10 g) and 99.42 g of deuterated DMSO were weighed and added to the reaction system, and the reaction system was heated to 80°C. After intermediate D-01 was completely dissolved in the deuterated DMSO solution, 7 g of sodium hydroxide was weighed and added to the reaction system. The reaction system was heated to 120°C and stirred for 72 hours. The reaction system was then cooled to 50°C and the reaction solution was distilled under reduced pressure until no more liquid was released. The distilled solid was purified by column chromatography (eluent: ethyl acetate:petroleum ether = 1:40) to obtain intermediate A-02 (8.65 g, yield 85%).

[0069] Intermediate A-02 was subjected to the following analytical tests.

[0070] HPLC purity is greater than 99% Mass spectrometry gave a calculated value of 172.25 and a measured value of 172.20.

[0071] 2) Synthesis of intermediate D-01

[0072] [ka]

[0073] Under nitrogen gas protection, intermediate A-02 (34.83 mmol, 6.0 g) and iridium trichloride trihydrate (13.93 mmol, 4.91 g) were weighed and added to the reaction system, and a mixed solution of 180 ml of ethylene glycol ether and 60 ml of purified water was added. Under nitrogen gas protection, the mixture was stirred at 120°C for 56 hours. The temperature of the reaction system was then lowered to 30°C, and a precipitate separated out from the solution. The precipitate was filtered under reduced pressure and washed with water, absolute ethanol, and petroleum ether in that order. The resulting solid was dried to obtain intermediate D-01 (5.08 g, yield 64%).

[0074] 3) Synthesis of intermediate D-02

[0075] [ka]

[0076] Intermediate D-01 (2.63 mmol, 3 g) was weighed, and silver trifluoromethanesulfonate (5.79 mmol, 1.5 g) was added. 90 ml of dichloromethane and 30 ml of methanol were then added to the system, and the mixture was stirred at 25°C for 56 hours under nitrogen gas protection. The reaction was completed, and the reaction solution was distilled until no more liquid flowed out. The mixture was then subjected to column chromatography (eluent: dichloromethane), and the receiving solution was distilled under reduced pressure until no more solids precipitated, yielding intermediate D-02 (3.84 g, yield 98%).

[0077] 4) Synthesis of organometallic compound L006

[0078] [ka]

[0079] Intermediate D-02 (4.03 mmol, 3 g) was weighed, and Intermediate B-02 (12.08 mmol, 3.28 g) was added. 60 ml of absolute ethanol was then added to the system. Under nitrogen gas protection, the mixture was refluxed at 90°C for 24 hours. Upon completion of the reaction, the mixture was filtered under reduced pressure. The filter cake was rinsed with absolute ethanol and petroleum ether at (60-90)°C in turn and dried under vacuum at 80°C. After drying, the solid was subjected to silica gel column chromatography (eluent: dichloromethane). The filtrate was concentrated to precipitate a solid, yielding organometallic compound L006 (1.26 g, yield 39%).

[0080] The organometallic compound L006 was subjected to the following analytical tests.

[0081] HPLC purity is greater than 99.8% HMOM:-5.35ev, LUMO:-2.65ev, Mass spectrometry gave a calculated value of 804.98 and a measured value of 804.90, as shown in FIG.

[0082] In this embodiment, the application of the above organometallic compounds in the manufacture of organic electroluminescent device products.

[0083] Compound Example 3 This example provides an organometallic compound L271, namely, the compound numbered L271, and the specific synthesis steps are as follows:

[0084] 1) Synthesis of intermediate E-01

[0085] [ka]

[0086] The intermediate 2-bromo-4-methylpyridine (29.07 mmol, 5 g), 4-methylphenylboronic acid (34.88 mmol, 4.74 g), 80 ml of toluene, 80 ml of water, and 75 ml of absolute ethanol were weighed and added to the reaction system. The reaction mixture was purged with nitrogen gas twice. Under nitrogen gas protection, 0.5 g of Pd(PPh3)4 and 12 g of potassium carbonate were added to the reaction system. The temperature outside the reaction system was set to 90 °C and maintained at 90 °C while stirring for 18 h. The reaction was monitored for completeness by TLC. The reaction system was then cooled to 30 °C, and the organic phase was extracted. The organic phase was dried over anhydrous sodium sulfate and evaporated under reduced pressure until no liquid flowed out. The evaporated solid was purified by column chromatography (eluent: ethyl acetate:petroleum ether = 1:20) to obtain intermediate E-01 (4.31 g, 81% yield).

[0087] Intermediate E-01 was subjected to the following analytical tests.

[0088] HPLC purity is greater than 99.5% Mass spectrometry gave a calculated value of 169.23 and a found value of 169.20.

[0089] 2) Synthesis of intermediate E-02

[0090] [ka]

[0091] Intermediate E-01 (21.83 mmol, 4 g) and 36.73 g of deuterated DMSO were weighed and added to the reaction system, and the reaction system was heated to 80°C. After intermediate E-01 was completely dissolved in the deuterated DMSO solution, 3.67 g of potassium hydroxide was weighed and added to the reaction system. The reaction system was heated to 120°C and stirred for 72 hours. The reaction system was then cooled to 50°C and the reaction solution was distilled under reduced pressure until no more liquid was flowing out. The distilled solid was purified by column chromatography (eluent: ethyl acetate:petroleum ether = 1:15) to obtain intermediate E-02 (3.14 g, yield 76%).

[0092] Intermediate E-02 was subjected to the following analytical tests.

[0093] HPLC purity is greater than 99.5% Mass spectrometry gave a calculated value of 189.29 and a found value of 189.20.

[0094] 3) Synthesis of intermediate F-01

[0095] [ka]

[0096] The intermediate 4-tert-butyl-2-pyridineboronic acid (33.51 mmol, 6 g), 6-bromodibenzo[b,d]furan-3-cyano group (16.76 mmol, 4.56 g), 120 ml of toluene, and 120 ml of water were weighed and added to the reaction system. The system was purged with nitrogen gas twice. Under nitrogen gas protection, 1 g of Pd(PPh3)4 and 6.95 g of potassium carbonate were added to the reaction system. The temperature outside the reaction system was set to 90 °C and maintained at 90 °C while stirring for 48 h. The reaction was monitored for completeness by TLC. The reaction system was cooled to 25 °C, the layers were separated, and the organic phase was extracted and dried over anhydrous sodium sulfate. The organic phase was evaporated under reduced pressure until no liquid flowed out. The evaporated solid was purified by column chromatography (eluent: ethyl acetate:petroleum ether = 1:1) to obtain intermediate F-01 (3.39 g, 62% yield).

[0097] Intermediate F-01 was subjected to the following analytical tests.

[0098] HPLC purity is greater than 99.2% Mass spectrometry gave a calculated value of 326.40 and a found value of 326.36.

[0099] 4) Synthesis of intermediate F-02

[0100] [ka]

[0101] A 2 L reaction flask was purged with nitrogen gas twice, and 180 ml of tetrahydrofuran and intermediate F-01 (9.19 mmol, 3.0 g) were added under nitrogen gas. The reaction mixture was cooled to -80 °C, and 2.5 mol / L n-butyllithium (27.5 mmol, 11 ml) was added dropwise. The mixture was allowed to react at low temperature for 6 hours. While maintaining the temperature, 300 ml of heavy water was added dropwise. After maintaining the temperature at low temperature for 30 minutes, the reaction mixture was allowed to naturally return to 25 °C and stirred for 10 hours. 100 ml of ethyl acetate was added, and the mixture was separated. The organic phase was distilled under reduced pressure from the reaction mixture until no liquid flowed out. The distilled solid was purified by column chromatography (eluent: ethyl acetate:petroleum ether = 1:3) to obtain intermediate B-02 (2.8 g, yield 93%).

[0102] Intermediate F-02 was subjected to the following analytical tests.

[0103] HPLC purity is greater than 99.1% Mass spectrometry gave a calculated value of 327.41 and a found value of 327.38.

[0104] 5) Synthesis of intermediate E-03

[0105] [ka]

[0106] Under nitrogen gas protection, intermediate E-02 (15.85 mmol, 3 g) and iridium trichloride trihydrate (7.92 mmol, 2.79 g) were weighed and added to the reaction system, and a mixed solution of 90 ml of ethylene glycol ether and 30 ml of purified water was added. Under nitrogen gas protection, the mixture was stirred at 120°C for 56 hours. The temperature of the reaction system was then lowered to 30°C, and a precipitate separated out from the solution. The precipitate was filtered under reduced pressure and washed successively with water, absolute ethanol, and petroleum ether. The resulting solid was dried to obtain intermediate E-03 (3.26 g, yield 68%).

[0107] 6) Synthesis of intermediate E-04

[0108] [ka]

[0109] Intermediate E-03 (2.48 mmol, 3 g) was weighed, and silver trifluoromethanesulfonate (6.21 mmol, 1.59 g) was added. 90 ml of dichloromethane and 30 ml of methanol were then added to the system, and the mixture was stirred at 25°C for 56 hours under nitrogen gas protection. The reaction was completed, and the reaction solution was distilled until no more liquid flowed out. The mixture was then subjected to column chromatography (eluent: dichloromethane), and the receiving solution was distilled under reduced pressure until no more solids precipitated, yielding intermediate E-04 (3.75 g, yield 97%).

[0110] 7) Synthesis of organometallic compound L271

[0111] [ka]

[0112] Intermediate E-04 (2.57 mmol, 2 g) was weighed, and Intermediate F-02 (7.70 mmol, 2.52 g) was added. 40 ml of absolute ethanol was then added to the system. Under nitrogen gas protection, the mixture was refluxed at 90°C for 24 hours. Upon completion of the reaction, the mixture was filtered under reduced pressure. The filter cake was rinsed with absolute ethanol and petroleum ether at (60-90)°C in turn and dried under vacuum at 80°C. After drying, the solid was subjected to silica gel column chromatography (eluent: dichloromethane). The filtrate was concentrated to precipitate a solid, affording organometallic compound L271 (1.43 g, 62% yield).

[0113] The organometallic compound L271 was subjected to the following analytical tests.

[0114] HPLC purity is greater than 99.6% HMOM:-5.33ev, LUMO:-2.49ev, Mass spectrometry gave a calculated value of 895.18 and a measured value of 895.15, as shown in FIG.

[0115] In this embodiment, the application of the above organometallic compounds in the manufacture of organic electroluminescent device products.

[0116] Compound Example 4 This example provides an organometallic compound L567, namely the compound numbered L567, and the specific synthesis steps are as follows:

[0117] 1) Synthesis of intermediate G-01

[0118] [ka]

[0119] The intermediate 2-bromo-4-methylpyridine (29.07 mmol, 5 g), deuterated phenylboronic acid (34.88 mmol, 4.43 g), 100 ml of toluene, 100 ml of water, and 50 ml of absolute ethanol were weighed and added to the reaction system. The reaction mixture was purged with nitrogen gas twice. Under nitrogen gas protection, 0.6 g of Pd(PPh3)4 and 12 g of potassium carbonate were added to the reaction system. The temperature outside the reaction system was set to 90 °C and maintained at 90 °C while stirring for 18 h. The reaction was monitored for completeness by TLC. The reaction system was then cooled to 30 °C, and the organic phase was extracted. The organic phase was dried over anhydrous sodium sulfate and evaporated under reduced pressure until no liquid flowed out. The evaporated solid was purified by column chromatography (eluent: ethyl acetate:petroleum ether = 1:25) to obtain intermediate G-01 (4.51 g, 89% yield).

[0120] Intermediate G-01 was subjected to the following analytical tests.

[0121] HPLC purity is greater than 99.6% Mass spectrometry gave a calculated value of 174.26 and a measured value of 174.33.

[0122] 2) Synthesis of intermediate G-02

[0123] [ka]

[0124] Intermediate G-01 (22.95 mmol, 4 g) and 51.51 g of deuterated DMSO were weighed and added to the reaction system, and the reaction system was heated to 80°C. After intermediate G-01 was completely dissolved in the deuterated DMSO solution, 1.2 g of sodium hydroxide was weighed and added to the reaction system. The reaction system was heated to 120°C and stirred for 72 hours. The reaction system was then cooled to 50°C and the reaction solution was distilled under reduced pressure until no more liquid was released. The distilled solid was purified by column chromatography (eluent: ethyl acetate:petroleum ether = 1:25) to obtain intermediate G-02 (3.54 g, yield 87%).

[0125] Intermediate G-02 was subjected to the following analytical tests.

[0126] HPLC purity is greater than 99.7% Mass spectrometry gave a calculated value of 177.28 and a measured value of 177.30.

[0127] 3) Synthesis of intermediate H-01

[0128] [ka]

[0129] The intermediate (4-isobutylpyridin-2-yl)boronic acid (55.86 mmol, 10 g), 6-bromodibenzo[b,d]furan-3-cyano group (27.93 mmol, 7.60 g), 200 ml of toluene, and 200 ml of water were weighed and added to the reaction system. The system was purged with nitrogen gas twice. Under nitrogen gas protection, 1.4 g of Pd(PPh3)4 and 11.58 g of potassium carbonate were added to the reaction system. The temperature outside the reaction system was set to 90 °C and maintained at 90 °C while stirring for 48 h. The reaction was monitored for completeness by TLC. The reaction system was then cooled to 25 °C, and the layers were separated. The organic phase was extracted and dried over anhydrous sodium sulfate. The organic phase was evaporated under reduced pressure until no liquid flowed out. The evaporated solid was purified by column chromatography (eluent: ethyl acetate:petroleum ether = 1:1) to obtain intermediate H-01 (5.10 g, 56% yield).

[0130] Intermediate H-01 was subjected to the following analytical tests.

[0131] HPLC purity is greater than 99.3% Mass spectrometry gave a calculated value of 326.40 and a found value of 326.36.

[0132] 4) Synthesis of intermediate H-02

[0133] [ka]

[0134] A 2 L reaction flask was purged with nitrogen gas twice, and 300 ml of tetrahydrofuran and intermediate H-01 (15.32 mmol, 5.0 g) were added under nitrogen gas. The reaction mixture was cooled to -80 °C, and 2.5 mol / L n-butyllithium (45.98 mmol, 18.4 ml) was added dropwise. The mixture was allowed to react at low temperature for 6 hours. While maintaining the low temperature, 500 ml of heavy water was added dropwise. After maintaining the low temperature for 30 minutes, the reaction mixture was allowed to naturally return to 25 °C and stirred for 10 hours. 200 ml of ethyl acetate was added, and the mixture was separated. The organic phase was distilled under reduced pressure from the reaction mixture until no liquid flowed out. The distilled solid was purified by column chromatography (eluent: ethyl acetate:petroleum ether = 1:3) to obtain intermediate H-02 (4.11 g, 82% yield).

[0135] Intermediate H-02 was subjected to the following analytical tests.

[0136] HPLC purity is greater than 99.1% Mass spectrometry gave a calculated value of 327.41 and a found value of 327.38.

[0137] 5) Synthesis of intermediate G-03

[0138] [ka]

[0139] Under nitrogen gas protection, intermediate G-02 (16.92 mmol, 3 g) and iridium trichloride trihydrate (7.92 mmol, 2.38 g) were weighed and added to the reaction system, and a mixed solution of 90 ml of ethylene glycol ether and 30 ml of purified water was added. Under nitrogen gas protection, the mixture was stirred at 120°C for 56 hours. The temperature of the reaction system was then lowered to 30°C, and a precipitate separated out from the solution. The precipitate was filtered under reduced pressure and washed successively with water, absolute ethanol, and petroleum ether. The resulting solid was dried to obtain intermediate G-03 (2.54 g, yield 65%).

[0140] 6) Synthesis of intermediate G-04

[0141] [ka]

[0142] Intermediate G-03 (2.16 mmol, 2.5 g) was weighed, and silver trifluoromethanesulfonate (5.40 mmol, 1.39 g) was added. 75 ml of dichloromethane and 28 ml of methanol were then added to the system, and the mixture was stirred at 25°C for 56 hours under nitrogen gas protection. The reaction was completed, and the reaction solution was distilled until no more liquid flowed out. The reaction solution was then subjected to column chromatography (eluent: dichloromethane), and the receiving solution was distilled under reduced pressure until no more solids precipitated, yielding intermediate G-04 (3.17 g, yield 97%).

[0143] 7) Synthesis of organometallic compound L567

[0144] [ka]

[0145] , Intermediate G-04 (3.97 mmol, 3 g) was weighed, and Intermediate H-02 (11.92 mmol, 3.9 g) was added. 60 ml of absolute ethanol was then added to the system. Under nitrogen gas protection, the mixture was refluxed at 80°C for 24 hours. Upon completion of the reaction, the mixture was filtered under reduced pressure. The filter cake was rinsed with absolute ethanol and petroleum ether at (60-90)°C in turn and dried under vacuum at 60°C. After drying, the solid was subjected to silica gel column chromatography (eluent: dichloromethane). The filtrate was concentrated to precipitate a solid, affording organometallic compound L567 (1.8 g, yield 52%).

[0146] The organometallic compound L567 was subjected to the following analytical tests.

[0147] HPLC purity is greater than 99.70% HMOM:-5.33ev, LUMO:-2.44ev, Mass spectrometry gave a calculated value of 869.14 and a measured value of 869.20 as shown in FIG.

[0148] In this embodiment, the application of the above organometallic compounds in the manufacture of organic electroluminescent device products.

[0149] The synthesis methods of other compounds are the same as above, and the description thereof is omitted here. The mass analysis and molecular formulas of other selected synthesis examples are shown in Table 1 below.

[0150] [Table 1]

[0151] Embodiments of the present invention further provide organic electroluminescent devices prepared with the organometallic compounds described above, more specifically, with the organometallic compounds shown in Chemical Formula 1.

[0152] Device Example 1 The compound L005 prepared in Example 1 was used to prepare an organic electroluminescent device, and the specific steps are as follows:

[0153] 1) Transparent glass with an anode material ITO on its surface was used as a substrate, which was then ultrasonically cleaned with deionized water, acetone, and ethanol for 15 minutes, respectively, and then treated with a plasma cleaner for 2 minutes. Then, the hole injection material HI-01 was deposited on the substrate with the anode by vacuum deposition to form a hole injection layer with a thickness of 100 Å.

[0154] 2) A hole transport material, HT-01, was deposited on the hole injection layer by vacuum deposition to form a hole transport layer with a thickness of 900 Å.

[0155] 3) An electron blocking material EB-01 was deposited on the hole transport layer by vacuum deposition to form an electron blocking layer with a thickness of 200 Å.

[0156] 4) A luminescent host material GH-02:GH-03=1:1 and a doping material L005 were mixed and deposited in a mass ratio of 90:10 on the electron blocking layer by vacuum deposition to form a luminescent layer with a thickness of 400 Å.

[0157] 5) A mixture of electron transport materials ET-01 and Liq was deposited in a mass ratio of 50:50 on the light-emitting layer by vacuum deposition to form an electron transport layer having a thickness of 400 Å.

[0158] 6) An electron injection material, LiF, was deposited on the electron transport layer by vacuum deposition to form an electron injection layer with a thickness of 150 Å.

[0159] 7) A cathode material, Al, was deposited on the electron injection layer by vacuum evaporation to form a cathode with a thickness of 1000 Å, that is, an organic electroluminescent device was obtained.

[0160] The other device examples and device comparative examples were prepared in the same manner as device example 1, except that the host material and doping material of the light-emitting layer were different from those of device example 1. The description thereof is omitted here, and the specific examples are shown in Table 2.

[0161] [Table 2] JPEG2025537288000061.jpg196169

[0162] The structure of the above device is as follows:

[0163] [ka] JPEG2025537288000063.jpg192169

[0164] The organic electroluminescent devices obtained in the device examples 1 to 22 and the device comparative examples 1 to 22 were also measured at a current density of 10 mA / cm. 2 The performance was measured under the above conditions, and the measurement results are shown in Table 3.

[0165] [Table 3]

[0166] As can be seen from Table 3, 1. Comparison of the comparative compounds GD-1, GD-2, GD-3, GD-4, GD-5, GD-6, and GD-19 with the organometallic compounds L005, L006, L271, L567, L010, and L043 of the present invention shows that the organic electroluminescent devices prepared using the compounds of the present invention as the doping material for the light-emitting layer by changing the combination of substituents in dibenzofuran, such as changing -H, -CD3, -C2D7, and -C6D5 to D and F to -CN, have significantly reduced driving voltages and significantly improved current efficiencies and lifetimes compared with the organic electroluminescent devices using the comparative compounds.

[0167] 2. Comparison of the comparative compounds GD-7, GD-8, GD-9, GD-10, GD-11, GD-12, GD-13, GD-14, GD-15, GD-16, GD-17, and GD-18 with the organometallic compound L005 of the present invention shows that the organic electroluminescent devices fabricated using the compounds of the present invention as the doping materials for the emitting layer at the positions of D and cyano groups exhibit significantly reduced driving voltages and significantly improved current efficiencies and lifetimes compared with the organic electroluminescent devices using the comparative compounds.

[0168] 3. The organic electroluminescent device manufactured using the organometallic compound provided by the present invention as a doping material for the emitting layer has a significantly lower driving voltage and significantly improved current efficiency and lifespan compared to the organic electroluminescent device manufactured using the comparative compounds Comparative Examples 1 to 22 as a doping material for the emitting layer.

[0169] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be 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 present invention. Therefore, the present invention is not limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. [Brief explanation of the drawings]

[0170] [Figure 1] 1 is a proton nuclear magnetic resonance spectrum of intermediate B-01. [Figure 2] 1 is a proton nuclear magnetic resonance spectrum of intermediate B-02. [Figure 3] This is the mass spectrum of organometallic compound L005. [Figure 4] This is the mass spectrum of organometallic compound L006. [Figure 5] This is the mass spectrum of organometallic compound L271. [Figure 6] This is a mass spectrum of the organometallic compound L567.

Claims

1. An organometallic compound having a structural formula of Ir(L 1 ) m (L 2 ) n Among them, L 1 and L 2 are both ligands, and 【Chemistry 1】 and Among them, * is a bond, R 1 ~R 8 are each independently -H, -D, -T, -F, -CN, or -CH 3 , -CD 3 , -CT 3 , -CF 3 , -CH 2 F, -CHF 2 , a substituted or unsubstituted C2 to C6 alkyl group, a substituted or unsubstituted C6 to C10 aryl group; Ar 1 ~Ar 4 are each independently -H, -D, -T, -F, -CN, or -CH 3 , -CD 3 , -CT 3 , -CF 3 , -CH 2 F, -CHF 2 , substituted or unsubstituted C2 to C6 alkyl groups; Organometallic compounds.

2. R 1 ~R 8 and Ar 1 ~Ar 4 wherein each alkyl group is independently one selected from a substituted or unsubstituted linear alkyl group, a substituted or unsubstituted branched alkyl group, and a substituted or unsubstituted cycloalkyl group. The organometallic compound of claim 1.

3. The organometallic compound Ir(L 1 ) m (L 2 ) n is characterized in that it is represented by any one of the following formulas L001-L880: The organometallic compound of claim 1. 【Chemistry 2】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】 【change】

4. An organic layer containing the organometallic compound according to any one of claims 1 to 3, Organic electroluminescent devices.

5. The organic electroluminescent device further includes a first electrode and a second electrode, and the organic layer is located between the first electrode and the second electrode, wherein: The organic layer includes a light-emitting layer containing an organometallic compound.

5. The organic electroluminescent device of claim 4.

6. the light-emitting layer includes a host material and a doping material containing an organometallic compound, and the mass ratio of the host material to the doping material is (10-99.5):0.5; 6. The organic electroluminescent device of claim 5.

7. The organic electroluminescent device according to claim 4 in the manufacture of an organic light-emitting device, an organic solar cell, an electronic paper, an organic photoreceptor or an organic thin film transistor, application.

Images