A deuterated compound for organic electroluminescent material

Abstract

The application belongs to the technical field of organic electroluminescent materials, and relates to a deuterated compound for an organic electroluminescent material. The application provides a deuterated compound for an organic electroluminescent material. After deuterium atoms are selectively positioned and introduced in the luminescent material, the spin-orbital coupling effect of the luminescent molecule will be enhanced, which will increase the intersystem crossing ability of the electron in the molecule, thereby facilitating the generation of phosphorescence and increasing the luminescent efficiency. The compound provided by the application is suitable as an organic electroluminescent material, and has the performance of reducing the driving voltage of a device and improving the brightness efficiency and service life of the device.

Description

Technical Field

[0001] This invention belongs to the field of organic electroluminescent materials technology, and relates to a deuterated compound for use in organic electroluminescent materials. Background Technology

[0002] Due to the "heavy atom effect," the introduction of deuterium (D) atoms into luminescent materials enhances the spin-orbit coupling of the luminescent molecules, increasing the intersystem crossing (ISC) capability and thus promoting phosphorescence generation and increasing luminescence efficiency. Furthermore, the introduction of deuterium atoms lowers the energy of the luminescent material due to the shorter bond length and higher bond energy of the carbon-deuterium bond, significantly improving the stability and lifetime of the luminescent device. Therefore, to maximize the performance of phosphorescent materials, it is necessary to dope them into the host material to reduce the quenching effect of the luminescent material itself, thereby achieving higher device performance. Phosphorescent materials themselves have high triplet energy; as the host material for phosphorescence, its energy must be higher than that of the luminescent material, otherwise energy backflow can easily occur, reducing luminescence efficiency. While phosphorescent host materials have seen significant development in recent years, host materials with high triplet energy and good stability are still rare, and developing more high-performance phosphorescent host materials remains a hot topic in the industry. In terms of the actual needs of the current OLED display and lighting industry, the development of OLED materials is far from sufficient and lags behind the requirements of panel manufacturers. Therefore, it is particularly important for material companies to develop higher-performance organic functional materials. Summary of the Invention

[0003] Introducing deuterium (D) atoms into luminescent materials is beneficial for phosphorescence generation, increases luminescence efficiency, and improves the performance of the luminescent materials. The purpose of this invention is to explore deuterated compounds for organic electroluminescent materials and to provide a method for preparing deuterated compounds with greater selectivity and smaller amounts of deuterium source. To this end, this invention provides a deuterated compound for organic electroluminescent materials to address this need in the art.

[0004] On one hand, the present invention relates to a deuterated compound for use in organic electroluminescent materials, having a structure shown in any one of Formulas I to III.

[0005]

[0006] R1 or R2 is independently selected from one of phenyl, naphthyl, anthracene, phenanthryl, biphenyl, furan, and carbazole.

[0007] On the other hand, the present invention relates to a method for preparing a deuterated compound, comprising: dissolving the compound to be deuterated in an organic solvent, adding a solid acid catalyst and heavy water, and heating to carry out a hydrogen-deuterium exchange reaction;

[0008] The compound to be deuterated is an aromatic compound or a heterocyclic aromatic compound.

[0009] Furthermore, in the method for preparing deuterated compounds provided by the present invention, the heteroatom in the heterocyclic aromatic compound is at least one of O, N, and S.

[0010] Furthermore, in the method for preparing the deuterated compound provided by the present invention, the deuterated compound to be substituted is one of benzene, naphthalene, anthracene, phenanthrene, pyrene, fluorene, β-carbazole, carbazole, benzo[a]anthracene, benzo[a]fluorene, dibenzo[a]furan, dibenzo[a]thiophene, 9-phenylanthracene, 9-naphthylanthracene, N-phenylcarbazole, N-naphthylcarbazole, and diphenylamine.

[0011] Furthermore, in the method for preparing deuterated compounds provided by the present invention, the aromatic compound is free of substituents or contains one or more substituents; each substituent is independently selected from one of fluorine, chlorine, bromine, iodine, alkyl, alkoxy, aryl, amino, and hydroxyl groups.

[0012] Furthermore, in the method for preparing the deuterated compound provided by the present invention, the solid acid catalyst is at least one selected from sulfuric acid / zirconium dioxide, sulfuric acid / titanium dioxide, sulfuric acid / silica, sulfuric acid / activated alumina, phosphotungstic acid / zirconium dioxide, phosphotungstic acid / titanium dioxide, phosphomolybdic acid / zirconium dioxide, phosphomolybdic acid / titanium dioxide, sulfonic acid resin, and perfluorosulfonic acid resin.

[0013] Furthermore, in the method for preparing the deuterated compound provided by the present invention, the organic solvent is selected from at least one of methylcyclohexane, decahydronaphthalene, toluene, xylene, tert-butylbenzene, chlorobenzene, o-dichlorobenzene, and 1,2,4-trichlorobenzene.

[0014] Furthermore, the method for preparing the deuterated compound provided by the present invention includes: adding heavy water in at least two batches to carry out multiple hydrogen-deuterium exchange reactions;

[0015] After each hydrogen-deuterium exchange reaction, the aqueous phase is separated, and heavy water is added again to carry out the next hydrogen-deuterium exchange reaction.

[0016] Furthermore, in the method for preparing the deuterated compound provided by the present invention, the mass ratio of the deuterated compound to be deuterated, heavy water and the solid acid catalyst is 1:2~20:0.03~0.5.

[0017] Furthermore, in the method for preparing the deuterated compound provided by the present invention, the heating temperature is 80~180℃;

[0018] The hydrogen-deuterium exchange reaction is carried out in an inert gas environment.

[0019] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages:

[0020] On the one hand, this invention selectively deuterates to form a class of deuterated compounds, which improves the efficiency, lifetime, and other properties of organic electroluminescent materials. The compounds provided by this invention, as the host material for the light-emitting layer, can significantly improve the performance of light-emitting devices, achieving high efficiency and long lifespan, and are widely applicable to OLED light-emitting devices and display devices.

[0021] On the other hand, the preparation method provided by this invention uses heavy water as a deuterium source, substituted or unsubstituted aromatic compounds or heterocyclic compounds as raw materials, and a solid acid as a catalyst to achieve a selective and directional deuteration reaction of aromatic compounds. The preparation method provided by this invention uses a solid acid as a catalyst, and the formation mechanism of the acidic center in the solid acid differs from that of liquid acids. Using SO4... 2- Taking MxOy type solid acids as an example, the formation of their acidic centers involves sulfate ions (SO42-). 2- The adsorption and coordination of S=O on the catalyst surface enhances the electron-acquiring ability of the corresponding metal ions, leading to a shift in the electron cloud of the MO bond and thus enhancing the selectivity of deuteration. The preparation method provided by this invention uses solid acid as a catalyst. The separation of the solid acid catalyst from the product after the reaction is relatively simple; the deuterium source can be recovered through simple operations such as filtration and liquid separation, significantly reducing deuterium loss. This is a significant advantage in industrial production, reducing separation costs and improving production efficiency. Solid acid catalysts can be repeatedly regenerated, exhibiting high activity and good selectivity, which reduces catalyst consumption and waste generation, lowering production costs. Solid acids are environmentally friendly catalysts, possessing high activity, no pollution, and no equipment corrosion, reducing the generation of industrial wastewater. Attached Figure Description

[0022] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of an organic electroluminescent element.

[0024] Wherein, 1 is the substrate, 2 is the anode layer, 3 is the hole injection layer, 4 is the first hole transport layer, 5 is the second hole transport layer, 6 is the light-emitting layer, 7 is the hole blocking layer, 8 is the electron transport layer, 9 is the electron injection layer, and 10 is the cathode layer. Detailed Implementation

[0025] The technical solution of the present invention will be described below with reference to embodiments. However, the present invention is not limited to the following embodiments. Unless otherwise specified, the experimental and detection methods described in each embodiment are conventional methods; the reagents and materials described are commercially available unless otherwise specified. Unless otherwise specified, all percentages in the following embodiments refer to mass percentages. Unless otherwise specified, all proportions in the following embodiments refer to mass ratios.

[0026] Sulfuric acid / zirconium dioxide, sulfuric acid / titanium dioxide, sulfuric acid / silica, sulfuric acid / activated alumina, phosphotungstic acid / zirconium dioxide, phosphotungstic acid / titanium dioxide, phosphomolybdic acid / zirconium dioxide, and phosphomolybdic acid / titanium dioxide were all purchased from Qiyuan (Guangdong) Pharmaceutical Chemical Co., Ltd., with product batch numbers 2024012606R, 2024012607R, 2024012608R, 2024012609R, 2024012610R, 2024012611R, 2024012612R, and 2024012613R, respectively; sulfonic acid resin and perfluorosulfonic acid resin were purchased from Nanda Synthetic Chemical Co., Ltd., with product models HNF-5W and HND-31, respectively.

[0027] Example 1

[0028] This embodiment provides the synthesis of bis(phenyl-2,4,6-D3)amine.

[0029]

[0030] 5 g (29.55 mmol) of diphenylamine and 40 mL of o-xylene were added to the reaction flask after nitrogen purging. Then, 6 g of heavy water and 1.0 g of sulfonic acid resin were added. The mixture was stirred and heated to 90 °C for hydrogen-deuterium exchange reaction for 10 h. After the reaction was completed, the aqueous phase was separated and the deuteration rate was 63% as determined by GCMS.

[0031] The hydrogen-deuterium exchange reaction was carried out a second time using the same reaction method. For each hydrogen-deuterium exchange reaction, 6g of heavy water was added to the system, and the mixture was stirred and heated to 90℃ for 10 hours under nitrogen protection. The aqueous phase was then separated before proceeding to the next hydrogen-deuterium exchange reaction. The ratio of diphenylamine, heavy water, and sulfonic acid resin used was 1g:3.6g:0.2g.

[0032] After the third hydrogen-deuterium exchange reaction, the sulfonic acid resin was first removed by filtration, and the mixture was allowed to stand and separated to recover the heavy water. 100 mL of toluene was added to the organic phase for extraction, followed by washing with water and solvent removal to obtain 4.8 g of bis(phenyl-2,4,6-D3)amine (yield 92.8%) with a GC purity of 99.7% and a deuteration rate of 95% as determined by GC-MS.

[0033] The characterization data are as follows: 1H NMR (600MHz, DMSO-d6) δ 8.15 (s, 1H), 7.22 (m, 4H), 7.07 (d, 0.16H), 6.81 (t, 0.06H). MS (EI) 175.2.

[0034] Example 2

[0035] This embodiment provides the synthesis of 9-hydro-carbazole-1,3,6,8-D4.

[0036]

[0037] 5 g (29.90 mmol) of carbazole and 50 mL of 1-chlorobenzene were added to the reaction flask after the displacement was completed. Then, 8 g of heavy water and 0.8 g of perfluorosulfonic acid resin were added. The mixture was stirred and heated to 120 °C for hydrogen-deuterium exchange reaction for 10 h. After the reaction was completed, the aqueous phase was separated and the deuteration rate was detected by GC-MS to be 55%.

[0038] The hydrogen-deuterium exchange reaction was repeated twice using the same reaction method. For each reaction, 8g of heavy water was added to the system, and the mixture was stirred and heated to 120℃ for 10 hours under nitrogen protection. The aqueous phase was then separated before the next hydrogen-deuterium exchange reaction. The ratio of carbazole, heavy water, and perfluorosulfonic acid resin used was 1g:4.8g:0.16g.

[0039] After three hydrogen-deuterium exchange reactions, the perfluorosulfonic acid resin was first removed by filtration, the mixture was allowed to stand and separated, and the heavy water was recovered. Then, 100 mL of toluene was added for extraction, followed by washing with water and solvent removal to obtain 44.9 g of 9-hydro-carbazole-1,3,6,8-D (yield 95.6%), with a GC purity of 99.5% and a deuteration rate of 98% as determined by GC-MS.

[0040] The characterization data are as follows: 1 H NMR (600MHz, DMSO-d6) δ 11.25 (s, 1H, NH), 8.11 (s, 2H), 7.49 (d, 0.08H), 7.38 (t, 1.98H), 7.15 (t, 0.09H). MS (EI) 171.2.

[0041] Example 3

[0042] This example provides the synthesis of 1-naphthylamine-2,4-D2.

[0043]

[0044] 5g (34.94mmol) of 1-naphthylamine and 50mL of methylcyclohexane were added to the reaction flask after nitrogen purging. Then, 5g of heavy water and 1.5g of sulfuric acid / titanium dioxide were added. The mixture was stirred and heated to 100℃ for hydrogen-deuterium exchange reaction for 10h. After the reaction was completed, the aqueous phase was separated and the deuteration rate was 58% as determined by GC-MS.

[0045] The hydrogen-deuterium exchange reaction was repeated twice using the same reaction method. For each reaction, 5g of heavy water was added to the system, and the mixture was stirred and heated to 100℃ for 10 hours under nitrogen protection. The aqueous phase was then separated before the next hydrogen-deuterium exchange reaction. The ratio of 1-naphthylamine, heavy water, and sulfuric acid / titanium dioxide used was 1g:3g:0.3g.

[0046] After three hydrogen-deuterium exchange reactions, sulfuric acid / titanium dioxide was first removed by filtration, the mixture was allowed to stand and separated, and heavy water was recovered. Then, 100 mL of toluene was added for extraction, followed by washing with water and solvent removal to obtain 24.6 g of 1-naphthylamine-2,4-D (yield 92.1%), with a GC purity of 99.8% and a deuteration rate of 97% as determined by GC-MS.

[0047] The characterization data are as follows: 1 H NMR (600MHz, DMSO-d6) δ 8.06 (d, 1H) , 7.71 (d, 1H) , 7.39 (dt, 1H) , 7.35 (dt, 0.98H) , 7.19 (t, 0.99H) , 7.07 (d, 0.08H) , 6.67 (d,0.06H). MS (EI) 145.1.

[0048] Example 4

[0049] This embodiment provides a combination of solid acid catalysts for the synthesis process.

[0050]

[0051] 5 g (29.55 mmol) of diphenylamine and 40 mL of o-xylene were added to the reaction flask after nitrogen purging. Then, 6 g of heavy water, 0.5 g of sulfuric acid / titanium dioxide and 0.5 g of sulfonic acid resin were added. The mixture was stirred and heated to 90 °C for hydrogen-deuterium exchange reaction for 10 h. After the reaction was completed, the aqueous phase was separated and the deuteration rate was 63% as determined by GCMS.

[0052] The hydrogen-deuterium exchange reaction was repeated a second time using the same reaction method. For each hydrogen-deuterium exchange reaction, 6g of heavy water was added to the system, and the mixture was stirred and heated to 90℃ for 10 hours under nitrogen protection. The aqueous phase was then separated before proceeding to the next hydrogen-deuterium exchange reaction. The ratio of diphenylamine, heavy water, sulfuric acid / titanium dioxide, and sulfonic acid resin used was 1g:3.6g:0.1g:0.1g.

[0053] After the third hydrogen-deuterium exchange reaction, the solid acid catalyst was first removed by filtration, and the mixture was allowed to stand and separated to recover the heavy water. 100 mL of toluene was added to the organic phase for extraction, followed by washing with water and solvent removal to obtain 4.7 g of bis(phenyl-2,4,6-D3)amine (yield 90.5%) with a GC purity of 99.5% and a deuteration rate of 94.5% as determined by GC-MS.

[0054] The characterization data are as follows: 1 H NMR (600MHz, DMSO-d6) δ 8.15 (s, 1H), 7.22 (m, 4H), 7.07 (d, 0.16H), 6.81 (t, 0.06H). MS (EI) 175.2.

[0055] Example 5

[0056] This embodiment provides a combination of solid acid catalysts for the synthesis process.

[0057]

[0058] 5 g (34.94 mmol) of 1-naphthylamine and 50 mL of methylcyclohexane were added to the reaction flask after nitrogen purging. Then, 5 g of heavy water, 1 g of sulfuric acid / activated alumina and 0.5 g of phosphotungstic acid / zirconia were added. The mixture was stirred and heated to 100 °C for hydrogen-deuterium exchange reaction for 10 h. After the reaction was completed, the aqueous phase was separated and the deuteration rate was detected by GC-MS to be 58%.

[0059] The hydrogen-deuterium exchange reaction was repeated twice using the same reaction method. For each reaction, 5g of heavy water was added to the system, and the mixture was stirred and heated to 100℃ for 10 hours under nitrogen protection. The aqueous phase was then separated before the next hydrogen-deuterium exchange reaction. The ratio of 1-naphthylamine, heavy water, and sulfuric acid / titanium dioxide used was 1g:3g:0.3g.

[0060] After three hydrogen-deuterium exchange reactions, the solid acid catalyst was first removed by filtration, the mixture was allowed to stand and separated, and the heavy water was recovered. Then, 100 mL of toluene was added for extraction, followed by washing with water and solvent removal to obtain 24.4 g of 1-naphthylamine-2,4-D (yield 89.8%), with a GC purity of 99.4% and a deuteration rate of 95% as determined by GC-MS.

[0061] The characterization data are as follows: 1H NMR (600MHz, DMSO-d6) δ 8.06 (d, 1H) , 7.71 (d, 1H) , 7.39 (dt, 1H) , 7.35 (dt, 0.98H) , 7.19 (t, 0.99H) , 7.07 (d, 0.08H) , 6.67 (d,0.06H). MS (EI) 145.1.

[0062] Example 6

[0063] This embodiment provides a device example of the application of a representative compound from the compounds provided in this invention as a luminescent material.

[0064] , ,

[0065]

[0066] Under nitrogen protection, compound I-1 (10.0 g, 19.6 mmol), compound I-2 (3.5 g, 20.0 mmol), sodium tert-butoxide (2.8 g, 30.0 mmol), Pd(OAc)₂ (0.02 g, 0.1 mmol), S-Phos (0.08 g, 0.2 mmol), and toluene (100 mL) were added to a three-necked flask. After purging the flask three times with nitrogen, the mixture was heated to 106 °C and reacted for 2 h. The reaction solution was cooled to room temperature, washed with water until neutral, dried over anhydrous sodium sulfate, concentrated, and recrystallized from toluene / ethanol (volume ratio 2:1) to obtain 9.5 g of compound I-3, with a yield of 75%.

[0067] The obtained sample characterization results are as follows: HR-MS (APCI): m / z 649.2852 [M+H] + Calculated values ​​of C45H24D6N4O (%): C, 83.31; H, 5.59; N, 8.64; Measured values: C, 83.26; H, 5.50; N, 8.57.

[0068]

[0069] Under nitrogen protection, compound II-1-1 (12.0 g, 76.4 mmol), compound II-1-2 (11.1 g, 76.6 mmol), sodium tert-butoxide (11.03 g, 114.8 mmol), Pd(OAc)₂ (0.08 g, 0.38 mmol), XantPhos (0.3 g, 0.76 mmol), and toluene (100 mL) were added to a three-necked flask. After purging the flask three times with nitrogen, the mixture was heated to 106 °C and reacted for 3 h. The reaction solution was cooled to room temperature, washed with water until neutral, dried over anhydrous sodium sulfate, concentrated, and recrystallized from toluene / ethanol (volume ratio 2:5) to obtain 14.3 g of compound II-1, with a yield of 85%.

[0070] Under nitrogen protection, compound II-1 (10.0 g, 21.3 mmol), compound II-2 (4.7 g, 21.3 mmol), sodium tert-butoxide (3.1 g, 32.0 mmol), Pd2(dba)3 (0.9 g, 0.1 mmol), Ru-Phos (0.9 g, 0.2 mmol), and toluene (100 mL) were added to a three-necked flask. After purging the flask three times with nitrogen, the mixture was heated to 106 °C and reacted for 2 h. The reaction solution was cooled to room temperature, washed with water until neutral, dried over anhydrous sodium sulfate, concentrated, and recrystallized from toluene / ethanol (volume ratio 3:1) to obtain 9.7 g of compound II-3, with a yield of 70%.

[0071] The characterization results of the obtained samples are as follows: HR-MS (APCI): m / z 655.8207 [M+H] + Calculated values ​​of C47H30D2N4 (%): C, 86.21; H, 5.23; N, 8.56 Measured values: C, 86.14; H, 5.14; N, 8.48.

[0072]

[0073] Under nitrogen protection, compound III-1 (10.0 g, 25.4 mmol), compound III-2 (4.5 g, 25.5 mmol), sodium tert-butoxide (3.7 g, 38.3 mmol), Pd2(dba)3 (0.9 g, 0.1 mmol), t-Bu3P·HBF4 (0.06 g, 0.2 mmol), and toluene (100 mL) were added to a three-necked flask. After purging the flask with nitrogen three times, the temperature was raised to 106 °C and the reaction was carried out for 2 h. The reaction solution was cooled to room temperature, washed with water until neutral, dried over anhydrous sodium sulfate, concentrated, and recrystallized from toluene / ethanol (volume ratio 3:4) to obtain 10.2 g of compound III-3, with a yield of 76%.

[0074] The sample characterization results are as follows: HR-MS (APCI): m / z 529.6580 [M+H] + Calculated values ​​of C37H20D4N4 (%): C, 84.06; H, 5.34; N, 10.60; Measured values: C, 83.96; H, 5.27; N, 10.52;

[0075] Device Examples

[0076] This embodiment provides an organic electroluminescent device, the specific structure of which is as follows: Figure 1 As shown, it includes a substrate 1, an anode layer 2, a hole injection layer 3, a first hole transport layer 4, a second hole transport layer 5, a light-emitting layer 6, a hole blocking layer 7, an electron transport layer 8, an electron injection layer 9, and a cathode layer 10, which are stacked in sequence.

[0077] Specifically, the anode layer 2 is made of indium tin oxide (ITO) with a high work function; the hole injection layer 3 is made of HAT-CN with a thickness of 5 nm; the first hole transport layer 4 is made of HT1 with a thickness of 60 nm; the second hole transport layer 5 is made of HT2 with a thickness of 15 nm; the light-emitting layer 6 uses compound 25 as the host material and BD01 as the light-emitting material, with a doping mass ratio of 3% and a thickness of 20 nm; the hole blocking layer 7 is made of HB with a thickness of 10 nm; the electron transport layer 8 is made of ET-1 with a thickness of 30 nm; the electron injection layer 9 is made of Liq with a thickness of 2 nm; and the cathode layer is made of Al with a thickness of 100 nm.

[0078] The basic material structures used in each functional layer of the device are as follows:

[0079]

[0080] The specific fabrication steps of the above-mentioned organic electroluminescent device are as follows:

[0081] 1) Clean the ITO anode on the transparent glass or plastic substrate by ultrasonic cleaning with deionized water, acetone and ethanol for 20 minutes each, and then perform plasma treatment in an oxygen atmosphere for 5 minutes.

[0082] 2) Hole injection layer material (HI) HATCN with a thickness of 5nm is deposited on the ITO anode layer by vacuum evaporation. This layer serves as the hole injection layer.

[0083] 3) Hole transport material HT1 with a thickness of 60nm is deposited on the hole injection layer by vacuum evaporation. This layer serves as the first hole transport layer.

[0084] 4) Hole transport material HT2 with a thickness of 15nm is deposited on the first hole transport layer HT1 by vacuum evaporation. This layer serves as the second hole transport layer.

[0085] 5) On the second hole transport layer, a light-emitting layer is co-deposited by vacuum evaporation, using compound I-3 as the host material and BD01 as the light-emitting material, with a doping mass ratio of 3% and a thickness of 20nm;

[0086] 6) Hole blocking material HB with a thickness of 10nm is deposited on the light-emitting layer by vacuum evaporation. This layer serves as the hole blocking layer.

[0087] 7) Electron transport material ET-1 with a thickness of 30nm is deposited on the hole blocking layer by vacuum evaporation. This layer serves as the electron transport layer.

[0088] 8) On the electron transport layer, the electron injection material Liq is deposited by vacuum evaporation with a thickness of 2nm. This layer serves as the electron injection layer.

[0089] 9) On the electron injection layer, cathode Al is deposited by vacuum evaporation with a thickness of 100 nm. This layer is used as the cathode conductive electrode.

[0090] The implementation process of Device Example 2 and Device Example 3 is the same as that of Device Example 1, except that the main material of the light-emitting layer is replaced by compound II-3 and compound III-3 instead of compound I-3.

[0091] Comparative Examples 1 to 3: Same as Device Example 1, except that compounds IV, V, and VI are used as the main materials of the light-emitting layer to replace compounds I-3, II-3, and III-3, respectively.

[0092]

[0093] The constituent components of the different devices prepared in Examples 1-24 and Comparative Example 1 of the present invention are shown in Table 1:

[0094] Table 1. Comparison of the constituent components of organic electroluminescent devices in various device embodiments.

[0095]

[0096] Each group of organic light-emitting diodes (OLEDs) connected their cathodes and anodes using a known driving circuit. The voltage-efficiency-current density relationship of the OLED devices was measured using a Keithley 2400 power supply and a PR670 photometer, following standard methods. Device lifetime was tested using a constant current method under the condition that the initial luminance was 1000 cd / m². 2The time it takes for the brightness to decay to 90% of the initial brightness is the device's LT90 lifetime. The test results are shown in Table 2.

[0097] Table 2. Performance results of organic electroluminescent devices

[0098]

[0099] As shown in Table 2, the compounds provided by this invention, when used as the main material for the luminescent layer in OLED devices, exhibit excellent performance. For example, compound III-3 in device example 3, compared to compound VI in comparative example 3, shows a significant improvement in both luminous efficiency and lifespan as the main material for blue light emission. The luminous efficiency is increased by 28.6%, and the device lifespan is increased by 53%. It is evident that using the compounds of this invention as the main material for the luminescent layer or as the luminescent material, compared to the application of non-deuterated materials in OLED light-emitting devices, significantly improves the luminous efficiency and lifespan performance of the devices, demonstrating promising industrialization prospects.

[0100] As described above, the basic principles, main features, and advantages of the present invention have been well described. The above embodiments and specifications are merely descriptions of preferred embodiments of the present invention, and the present invention is not limited to the above embodiments. Various changes and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit and scope of the present invention should fall within the protection scope defined by the present invention.

Claims

1. A method of preparing a deuterated compound by selective directed deuterium substitution, characterized in that, The application relates to a method for deuterating a compound. The compound to be deuterated is dissolved in an organic solvent, a solid acid catalyst and heavy water are added, and a hydrogen-deuterium exchange reaction is carried out by heating; the heavy water is added in at least two batches, and the hydrogen-deuterium exchange reaction is carried out for multiple times; after each hydrogen-deuterium exchange reaction, the aqueous phase is separated, and the heavy water is added again for the next hydrogen-deuterium exchange reaction; The mass ratio of the compound to be deuterated, the heavy water and the solid acid catalyst is 1:2-20:0.03-0.5; The compound to be deuterated is an aromatic compound or a heterocyclic aromatic compound; The heteroatom in the heterocyclic aromatic compound is at least one of O, N and S; the compound to be deuterated is one of benzene, naphthalene, anthracene, phenanthrene, pyrene, fluorene, chrysene, carbazole, benzanthracene, benzofluorene, dibenzofuran, dibenzothiophene, 9-phenylanthracene, 9-naphthylanthracene, N-phenylcarbazole, N-naphthylcarbazole and diphenylamine; the aromatic compound does not contain a substituent or contains one or more substituents; each substituent is independently selected from one of fluorine, chlorine, bromine, iodine, an alkyl group, an alkoxy group, an aryl group, an amine group and a hydroxyl group; and the solid acid catalyst is at least one of sulfuric acid / zirconium dioxide, sulfuric acid / titanium dioxide, sulfuric acid / silicon dioxide, sulfuric acid / activated alumina, phosphotungstic acid / zirconium dioxide, phosphotungstic acid / titanium dioxide, phosphomolybdic acid / zirconium dioxide, phosphomolybdic acid / titanium dioxide, sulfonic acid resin and perfluorosulfonic acid resin.

2. The method for preparing the deuterated compound according to claim 1, characterized in that, The organic solvent is at least one of methylcyclohexane, decaline, toluene, xylene, tert-butylbenzene, chlorobenzene, o-dichlorobenzene and 1,2,4-trichlorobenzene.

3. The method for preparing the deuterated compound according to claim 1, characterized in that, The heating temperature is 80-180 DEG C. The hydrogen-deuterium exchange reaction is carried out in an inert gas environment.

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