Asymmetric triptycene compound and electroluminescent device

Abstract

The invention belongs to the technical field of organic light-emitting materials and semiconductors, and particularly relates to an asymmetric triptycene compound and an electroluminescent device. According to the invention, triptycene is taken as a matrix, and the asymmetric triptycene compound is obtained by substituting a site 1 and a site 8 of the triptycene; the structural formula of the asymmetric triptycene compound is shown in the specification. The asymmetric triptycene compound is used as a guest luminescent material, and the prepared electroluminescent device has narrower half-peak width, higher luminous efficiency and longer service life. .

Description

Technical Field

[0001] This invention belongs to the field of organic light-emitting materials and semiconductor technology, specifically relating to an asymmetric triterpenoid compound and an electroluminescent device. Background Technology

[0002] Organic light-emitting diodes, or OLEDs for short, have attracted much attention in the lighting and display fields due to their excellent characteristics such as self-illumination, high brightness, high contrast, flexibility, low energy consumption, and wide viewing angle.

[0003] A typical OLED device usually consists of an anode layer, a hole transport layer, an emissive layer, an electron transport layer, and a cathode layer. Under the influence of an applied voltage, holes injected from the anode move to the emissive layer through the hole transport layer, while electrons injected from the cathode move to the emissive layer through the electron transport layer, recombine to form excitons, and the exciton energy is transferred to the luminescent material, thus causing light emission. The performance of the luminescent material in the emissive layer directly determines the overall luminous efficacy and lifespan of the OLED device; therefore, developing high-performance luminescent materials has become a key factor driving the development of OLED technology.

[0004] Triptene possesses a rigid three-dimensional cage-like framework. Its molecular structure consists of three benzene rings symmetrically fused together through a central cyclohexene structure, presenting an overall spatial configuration resembling a butterfly spreading its wings. This structure endows it with high rigidity, strong modifiability, and internal hydrophobic cavities, making tripterene a promising candidate for a wide range of applications in supramolecular chemistry, porous materials, luminescent materials, and organic electronics.

[0005] Currently, existing technologies report on trimerene-based compounds and their applications in OLED devices. For example, patent application number 201980062456.1 proposes a class of trimerene compounds as auxiliary dopants. Although these compounds possess good thermal stability and can effectively promote TADF-assisted fluorescence, the luminous efficiency of the fabricated OLED devices is still unsatisfactory. Patent application number 202210290018.4 discloses a symmetrical 1,8-disubstituted trimerene derivative as a luminescent material, achieving high blue light emission efficiency; however, the lifetime of the OLED device is insufficient.

[0006] Although triptenes possess unique properties and application potential in the field of luminescent materials, and existing technologies have explored triptene-based OLED luminescent materials, the currently disclosed triptene compounds still suffer from low luminous efficiency and insufficient lifespan, making it difficult to meet the higher requirements of OLED devices in terms of luminous performance, stability, and lifespan. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides an asymmetric tripterene compound and an electroluminescent device. This invention uses an asymmetric tripterene compound as a guest light-emitting material to solve the technical problems of insufficient lifetime and low luminous efficiency of guest light-emitting materials.

[0008] The first object of the present invention is to provide an asymmetric tripterene compound, the structural formula of which is shown in general formula 1, general formula 2, general formula 3 or general formula 4: ; Z1, Z2, and Z3 are each independently selected from C-R0 or N; R0 is selected from H, D, F, cyano, trifluoromethyl, C1-C6 alkyl, or phenyl; R1 and R2 are each independently selected from H, D, F, cyano, trifluoromethyl, C1-C6 alkyl, or phenyl; X is selected from O, S, or NR. 11 M1 is selected from B, P, P=O, P=S, and Si-R. 12 Ge-R 13 Sn-R 14 Or Sb; R3 to R5 are independently selected from H, methyl, ethyl, isopropyl, or tert-butyl; R8 to R 10 Each of the following is independently selected from H, methyl, ethyl, isopropyl, or tert-butyl; R is selected from C6 to C6. 20 Aryl groups.

[0009] Preferably, R is phenyl, 4-tert-butylphenyl, naphthyl, biphenyl, or 9,9-dimethylfluorenyl.

[0010] Preferably, Z1, Z2, and Z3 are all C-RO, and RO is selected from H, D, F, cyano, trifluoromethyl, methyl, ethyl, tert-butyl, phenyl, or deuterated methyl; R1 and R2 are each independently selected from H, D, F, cyano, trifluoromethyl, methyl, tert-butyl, phenyl, deuterated methyl, or deuterated tert-butyl; or, Z1 and Z3 are all N, R1 and R2 are both selected from phenyl, and R0 is selected from H; or, Z1, Z2, and Z3 are all N, and R1 and R2 are both selected from phenyl.

[0011] Preferred, R 11 It is selected from phenyl, 4-methylphenyl, 4-isopropylphenyl or 4-tert-butylphenyl.

[0012] Preferred, R 12 ~R 14 Each is independently selected from phenyl, methyl, ethyl, propyl, or butyl.

[0013] The asymmetric triterpenoid compound is selected from one of the following compounds: .

[0014] The second objective of this invention is to provide an electroluminescent device comprising an anode layer, a hole transport layer, an emitting layer, an electron transport layer, and a cathode layer stacked sequentially; the emitting layer is prepared from a host emitting material and a guest emitting material, wherein the guest emitting material is the aforementioned asymmetric triterpenoid compound.

[0015] Preferably, the mass of the guest luminescent material accounts for 1% to 3% of the mass of the luminescent layer.

[0016] Preferably, the host luminescent material is selected from one of the following compounds: .

[0017] Preferably, the anode layer is made of indium tin oxide, indium zinc oxide, tin dioxide, or zinc oxide; a material with a high work function is selected to facilitate the injection of holes into the organic layer composed of the hole transport layer, the light-emitting layer, and the electron transport layer.

[0018] Preferably, the cathode layer is made of at least one of magnesium, silver, aluminum, aluminum-lithium, calcium, magnesium-indium, and magnesium-silver. Choosing a material with a low work function facilitates the injection of electrons into the organic layer composed of the hole transport layer, the light-emitting layer, and the electron transport layer.

[0019] Preferably, the hole transport layer can be a single-layer hole transport layer containing only one compound, or it can be a composite hole transport layer containing multiple compounds. The composite hole transport layer is composed of multiple organic hole materials, including a hole injection layer, a hole transport layer, and an electron blocking layer stacked sequentially.

[0020] In this invention, the hole injection layer is preferably a p-doped hole injection layer, which refers to a hole injection layer doped with a p-doped agent. A p-doped agent is a material that can impart p-type semiconductor characteristics; p-type semiconductor characteristics refer to the characteristics of injecting or transporting holes at the HOMO energy level, that is, having high hole conductivity.

[0021] Preferably, the electron transport layer is a composite electron transport layer, comprising an electron injection layer, an electron transport layer, and a hole blocking layer, wherein the material of the electron transport layer is selected from at least one of E1, E2, and E3. .

[0022] Compared with the prior art, the present invention has the following beneficial effects: In the asymmetric triterpenoid compound structure of the present invention, such as Figure 2 The multi-electron resonance unit structure A possesses unique electronic delocalization properties, allowing for flexible adjustment of molecular frontier orbital energy levels. The push-pull electron group structure B can further construct a "donor-triptene framework-acceptor" or "multi-electron resonance-push-pull electron" synergistic effect, achieving precise control of the emission wavelength. Furthermore, the multi-electron resonance structure easily achieves a narrow half-width at half-maximum, contributing to improved color purity of OLEDs. Moreover, structure A, through electronic delocalization and resonance effects, significantly reduces the singlet-trittite energy level difference, promoting "intersystem crossing" and radiative transitions of triplet excitons while suppressing non-radiative transitions, thus improving fluorescence / delayed fluorescence quantum yield. Simultaneously, the push-pull electron group structure B can flexibly control HOMO / LUMO energy levels, matching them with the energy levels of the host material and electrodes, efficiently capturing holes and electrons and promoting recombination, thereby improving electroluminescence efficiency. The formation of a rigid planar structure through the resonant conjugation of multiple aromatic rings suppresses molecular thermal vibrations and aggregation, reducing exciton quenching while improving the thermal and chemical stability of the material, extending device lifetime.

[0023] The electroluminescent device of the present invention uses asymmetric triterpenoid compounds as guest light-emitting materials, which has high luminous efficiency and long service life. At the same time, the emission wavelength of the device is in the range of violet to visible light, which meets the application requirements of the device in different scenarios. Attached Figure Description

[0024] Figure 1 This is a cross-sectional view of the electroluminescent device of the present invention.

[0025] Figure 2 This is a structural diagram of the asymmetric triterpenoid compound represented by general formula 1 of the present invention.

[0026] Figure label: 1-Substrate, 2-Anode layer, 3-Hole injection layer, 4-Hole transport layer, 5-Electron blocking layer, 6-Light emitting layer, 7-Hole blocking layer, 8-Electron transport layer, 9-Electron injection layer, 10-Cathode layer, 11-Cover layer. Detailed Implementation

[0027] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0028] It should be noted that all process equipment or apparatus not specifically specified in the following embodiments are conventional equipment or apparatus in the art. This invention uses tripterene as a matrix and obtains asymmetric tripterene compounds with both structural A and structural B substitutions by substituting structure A at site 1 and structure B at site 8 of the tripterene. Structure A is provided by reactant a; structure B is provided by reactant b; reactant a is selected from at least one compound represented by formulas a1 to a27, and reactant b is selected from one compound represented by formulas b1 to b21.

[0029] .

[0030] It should be noted that the English name for High Performance Liquid Chromatography is HPLC; the English name for Liquid Chromatography-Mass Spectrometry is LC-MS; the Chinese name for Pd(dppf)Cl2 is 1,1-bis(diphenylphosphine)ferrocene palladium dichloride; the Chinese name for Pd(PPh3)4 is tetrakis(triphenylphosphine)palladium; the Chinese name for Pd2(dba)3 is tris(dibenzylindeneacetone)palladium; and the Chinese name for DIEA is N,N-diisopropylethylamine. m-chloroperoxybenzoic acid was purchased from Changzhou Zhuoxin Biotechnology Co., Ltd., CAS No.: 937-14-4, purity: 85%.

[0031] In a specific embodiment for synthesizing asymmetric triterpenoids, the synthetic routes for intermediates M1-1, M1-2, and compound M1 are as follows: .

[0032] The specific synthesis process is as follows: Synthesis of intermediate M1-1: Take a 2.0L three-necked flask equipped with a reflux tube and a dropping funnel, and add 0.2 mol of 1,8-dibromoanthracene, 0.33 mol of isoamyl nitrite, and 700 mL of ethylene glycol dimethyl ether in sequence. Start stirring and heat to 85°C. Slowly add 300 mL of ethylene glycol dimethyl ether solution containing 0.4 mol of an-aminobenzoic acid over 2 hours. After naturally cooling to room temperature, add 0.33 mol of isoamyl nitrite and heat to 85°C. Slowly add 300 mL of ethylene glycol dimethyl ether solution containing 0.4 mol of an-aminobenzoic acid over 2 hours. After naturally cooling to room temperature, add 100 mL of methanol to the reaction solution, followed by 1000 mL of 10% sodium hydroxide aqueous solution. At this point, some solid precipitates out. The reaction solution was cooled to 10°C and allowed to stand. When a large amount of solid precipitated, it was filtered. The obtained solid was washed with a mixed solution of methanol and water, in which the volume ratio of methanol to water was 4:1. The crude product was then dried.

[0033] Take a 1000mL flask equipped with a reflux tube, and add the above crude product, 25g of maleic anhydride, and 300mL of triethylene glycol dimethyl ether in sequence. Start stirring and heat to 180℃ for 15 minutes. After naturally cooling to room temperature, add 300mL of 10% sodium hydroxide aqueous solution. Cool the reaction solution to 10℃ and filter. The obtained solid is washed and dried with a mixed solution of methanol and water in a volume ratio of 4:1 to obtain intermediate M1-1; totaling 68.6g, yield 83.2%, HPLC purity 97%.

[0034] Synthesis of intermediate M1-2: Under nitrogen protection, 0.15 mol of intermediate M1-1, 0.17 mol of pinacol diborate, 0.3 mol of potassium acetate, and 800 mL of 1,4-dioxane were added to a 2000 mL three-necked flask. The mixture was stirred and heated to 60 °C, then 2.2 mmol of Pd(dppf)Cl2 was added. The mixture was then heated to reflux for 8 h until intermediate M1-1 was completely reacted. The reaction solution was directly filtered, and the filtrate was collected, concentrated under reduced pressure, dissolved in 500 mL of toluene, and washed with water. The organic phase was dried over anhydrous magnesium sulfate, filtered, and concentrated. After passing the organic phase through a silica gel column, the column chromatography solution was concentrated again under reduced pressure until solid precipitates. The solution was then cooled to 10–15 °C for crystallization, filtered, and dried to obtain intermediate M1-2; total yield 54.8 g, yield 79.6%, HPLC purity 98%.

[0035] Synthesis of compound M1: The synthesis method of intermediate M1-2 was similar, except that 0.1 mol of intermediate M1-1 was replaced with 0.1 mol of intermediate M1-2 to obtain compound M1; the total amount was 41.3 g, the yield was 81.5%, the HPLC purity was 98%, and the LC-MS showed a molecular weight of 506.3.

[0036] Example 1 The synthetic method for asymmetric triterpenoids is shown below, with the specific synthetic route as follows: .

[0037] Step 1, Synthesis of intermediate M2-1: 0.2 mol of 2,5-dibromo-1,3-difluorobenzene (formula a1), 0.4 mol of 4-tert-butylphenol (formula a2), 1.0 mol of NaH, and 400 mL of N,N-dimethylformamide were added to a 1000 mL three-necked flask. The mixture was stirred and heated to 100 °C for 5 h. After the reaction was completed, the reaction solution was cooled to room temperature, and 600 mL of ethyl acetate and 500 mL of saturated ammonium bicarbonate were added for washing. The ethyl acetate was used three times, with each use being 200 mL. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain a crude product. The crude product was subjected to silica gel column chromatography using dichloromethane and petroleum ether in a volume ratio of 10:1 to separate intermediate M2-1. The total yield was 97.4 g, with a yield of 91.5% and an HPLC purity of 98%.

[0038] Step 2, Synthesis of intermediate M2: Under nitrogen protection, 0.1 mol of intermediate M2-1 and 400 mL of tert-butylbenzene solution were added to a 1000 mL three-necked flask. The mixture was stirred and cooled to -40 °C. 75 mL of a 1.6 mol / L tert-butyllithium solution in n-hexane was added dropwise to obtain the reaction solution. The reaction solution was slowly heated to 60 °C and stirred for 2 hours, then cooled again to -10 °C. 0.03 mol of boron tribromide was added, and the mixture was allowed to react at room temperature for 1 hour. Then, 0.04 mol of N,N-diisopropylethylamine was added dropwise. After the addition was complete, the reaction solution was heated to 160 °C and reacted for 12 hours until the reaction was complete. The reaction solution was cooled to room temperature and concentrated. The residue was purified by silica gel column chromatography using petroleum ether and dichloromethane in a volume ratio of 8:1 to obtain intermediate M2, weighing 27.2 g, with a yield of 59.0% and an HPLC purity of 98%.

[0039] Step 3, Synthesis of Intermediate 1-1: Under nitrogen protection, 0.02 mol of intermediate M2, 0.02 mol of intermediate M1-2, 0.2 mmol of Pd(PPh3)4, 0.06 mol of K2CO3, 40 mL of tetrahydrofuran, and 10 mL of H2O were added to a 100 mL three-necked flask to obtain a reaction solution. The reaction solution was heated to reflux and reacted for 18 h until the reaction was complete. The reaction solution was washed with water and separated. The organic phase was passed through a diatomaceous earth funnel and the filtrate was collected. The filtrate was concentrated under reduced pressure to obtain a crude solid product. The residue was purified by silica gel column chromatography. The solvent used was petroleum ether and dichloromethane, with a volume ratio of petroleum ether to dichloromethane of 8:1, to obtain intermediate 1-1; totaling 10.0 g, yield 70.3%, HPLC purity 98%.

[0040] Step 4: Synthesis of asymmetric triterpenoids: Under nitrogen protection, 0.01 mol of intermediate 1-1, 0.01 mol of phenylboronic acid (formula b1), 0.1 mmol of Pd(PPh3)4, 0.03 mol of K2CO3, 40 mL of tetrahydrofuran, and 10 mL of H2O were added to a 100 mL three-necked flask to obtain a reaction solution. The reaction solution was heated to reflux and reacted for 18 h until the reaction was complete. The reaction solution was washed with water and separated. The organic phase was passed through a diatomaceous earth funnel and the filtrate was collected. The filtrate was concentrated under reduced pressure to obtain a crude solid product. The residue was purified by silica gel column chromatography. The solvent used was petroleum ether and dichloromethane in a volume ratio of 8:1 to obtain compound 1. The total yield was 5.1 g, with a yield of 71.2%, an HPLC purity of 99%, and a molecular weight of 710.5 as shown by LC-MS.

[0041] Example 2 The synthetic method for asymmetric triterpenoids is shown below, with the specific synthetic route as follows: .

[0042] Step 1, Synthesis of intermediate M3-1: Under nitrogen protection, 0.2 mol of 2,5-dibromo-1,3-difluorobenzene (formula a1), 0.4 mol of 4-tert-butyl-N-aniline (formula a4), 0.4 mol of cesium carbonate, and 500 mL of N,N-dimethylformamide were added to a 1000 mL three-necked flask. The mixture was stirred and heated to 130 °C for 8 hours. After the reaction was completed, the reaction solution was cooled to room temperature, and dichloromethane was added for washing with purified water. The organic phase was separated and retained, while the aqueous phase was further extracted with dichloromethane. The organic phases were combined, dried over anhydrous magnesium sulfate, concentrated, and purified by silica gel column chromatography. The solvents used were petroleum ether and dichloromethane in a volume ratio of 10:1, yielding intermediate M3-1, weighing 126.0 g, with a yield of 92.3% and an HPLC purity of 97%.

[0043] Step 2, Synthesis of intermediate M3: The synthesis method of intermediate M2 in Example 1 was followed, except that intermediate M2-1 was replaced with intermediate M3-1 to obtain intermediate M3; the total amount was 36.8g, the yield was 60.2%, and the HPLC content was 98%.

[0044] Step 3, Synthesis of Intermediate 17-1: The synthesis method of intermediate 1-1 in Example 1 was followed, except that intermediate M2 was replaced by intermediate M3 and intermediate M1-2 was replaced by compound M1 to obtain intermediate 17-1; totaling 12.8g, yield 70.4%, HPLC content 98%.

[0045] Step 4: Synthesis of asymmetric triterpenoids: The synthesis method of compound 1 in Example 1 was followed, except that 2-bromo-4,6-diphenyl-1,3,5-triazole as shown in formula b8 was used to replace intermediate 1-1, and intermediate 17-1 was used to replace phenylboronic acid as shown in formula b1, to obtain compound 17; total 7.2 g, yield 70.6%, HPLC purity 99%, LC-MS showed molecular weight 1015.8.

[0046] Example 3 The synthetic method for asymmetric triterpenoids is shown below, with the specific synthetic route as follows: .

[0047] Step 1, Synthesis of intermediate M4-1: The synthesis method of intermediate M2-1 in Example 1 was followed, except that 2-fluoro-4-tert-butylphenol as shown in Formula a9 was used to replace 4-tert-butylphenol as shown in Formula a2 to obtain intermediate M4-1; the total yield was 101.8, the yield was 89.6%, and the HPLC content was 98%.

[0048] Step 2: Synthesis of intermediate M4-2: Under nitrogen protection, 0.1 mol of M4-1, 0.1 mol of aniline (formula a18), 2 mmol of Pd2(dba)3, 5 mmol of 2-(di-tert-butylphosphine)biphenyl, 0.3 mol of sodium tert-butoxide, and 500 mL of toluene were added to a 1000 mL three-necked flask. The mixture was stirred and heated to 110 °C, and reacted for 12 h to obtain the reaction solution. After the reaction was complete, the reaction solution was directly filtered, the filtrate was collected, concentrated under reduced pressure, dissolved in 500 mL of toluene, washed with water, dried over anhydrous magnesium sulfate, filtered, and concentrated. The concentrate was purified by silica gel column chromatography using petroleum ether and dichloromethane in a volume ratio of 10:1 to obtain intermediate M4-2; totaling 49.8 g, yield 80.2%, HPLC purity 98%.

[0049] Step 3, Synthesis of intermediate M4: The synthesis method of intermediate M2 in Example 1 was the same, except that 0.05 mol of intermediate M4-2 was used to replace 0.1 mol of intermediate M2-1 to obtain intermediate M4, totaling 16.6 g, with a yield of 60.0% and an HPLC purity of 98%.

[0050] Step 4, Synthesis of Intermediate 37-1: The synthesis method of intermediate 1-1 in Example 1 was followed, except that intermediate M2 was replaced by intermediate M4 to obtain intermediate 37-1; totaling 11.4 g, yield 71.2%, HPLC content 98%.

[0051] Step 5: Synthesis of asymmetric triterpenoids: The synthesis method of compound 1 in Example 1 was followed, except that intermediate 1-1 was replaced with intermediate 37-1 to obtain compound 37; total amount 5.8g, yield 72.3%, HPLC purity 99%, LC-MS showed molecular weight 799.8.

[0052] 1H NMR data for compound 37: 1 H NMR (500 MHz, (CH3)2SO ) δ 7.73 (s, 1H),7.57-7.29 (m, 13H), 7.24 (s, 3H), 7.12-6.95 (m, 7H), 6.55 (s, 2H), 4.88 (d, J= 12.3 Hz, 2H), 1.37 (s, 18H).

[0053] Example 4 The synthetic method for asymmetric triterpenoids is shown below, with the specific synthetic route as follows: .

[0054] Step 1, Synthesis of intermediate M5-1: The synthesis method of intermediate M3-1 in Example 2 was followed, except that 4-tert-butyl-N-aniline represented by formula a4 was replaced with aniline represented by formula a18 to obtain intermediate M5-1; totaling 76.7 g, yield 91.7%, HPLC content 98%.

[0055] Step 2, Synthesis of intermediate M5-2: The synthesis method of intermediate M3-1 in Example 2 was followed, with the following differences: 0.1 mol of (2,2'-dioxy(1-(tert-butyl)-4-iodophenyl) as shown in formula a15 was used to replace 0.2 mol of 2,5-dibromo-1,3-difluorobenzene as shown in formula a1, and 0.1 mol of intermediate M5-1 was used to replace 0.4 mol of 4-tert-butyl-N-aniline as shown in formula a4, to obtain intermediate M5-2; totaling 57.8 g, yield 81.3%, HPLC purity 98%.

[0056] Step 3, Synthesis of intermediate M5: The synthesis method of intermediate M2 in Example 1 was followed, except that 0.05 mol of intermediate M5-2 was used to replace 0.1 mol of intermediate M2-1 to obtain intermediate M5; the total amount was 19.1 g, the yield was 60.0%, and the HPLC content was 98%.

[0057] Step 4, Synthesis of Intermediate 49-1: The synthesis method of intermediate 1-1 in Example 1 was followed, except that intermediate M2 was replaced with intermediate M5 to obtain intermediate 49-1; totaling 12.6 g, yield 71.6%, and HPLC content 98%.

[0058] Step 5: Synthesis of asymmetric triterpenoids: The synthesis method of compound 1 in Example 1 was followed, except that intermediate 1-1 was replaced by intermediate 49-1, and phenylboronic acid shown in formula b1 was replaced by 2,4-tert-butylphenylboronic acid shown in formula b4, to obtain compound 49; total amount 7.1 g, yield 72.3%, HPLC purity 99%, LC-MS showed molecular weight 986.7.

[0059] 1H NMR data for compound 49: 1 H NMR (500 MHz, (CH3)2SO) δ 7.61 (s, 1H),7.55-7.39 (m, 5H), 7.39-7.15 (m, 11H), 7.12-6.96 (m, 8H), 6.93 (s, 2H), 6.82(s, 2H), 4.84 (d, J = 21.5 Hz, 2H), 1.53-1.15 (m, 36H).

[0060] Example 5 The synthetic method for asymmetric triterpenoids is shown below, with the specific synthetic route as follows: .

[0061] Step 1: Synthesis of intermediate M6-1: The synthesis method of intermediate M2-1 in Example 1 was followed, except that o-fluorophenol represented by formula a11 was used to replace 4-tert-butylphenol represented by formula a2 to obtain intermediate M6-1; totaling 83.5g, yield 91.5%, HPLC content 98%.

[0062] Step 2, Synthesis of intermediate M6-3: The synthesis method of intermediate M4-2 in Example 3 was followed, except that 0.1 mol of intermediate M4-1 was replaced with 0.15 mol of intermediate M6-1 to obtain intermediate M6-3; the total yield was 63.1 g, the yield was 82.6%, and the HPLC content was 98%.

[0063] Step 3, Synthesis of intermediate M6: Under nitrogen protection, 400 mL of a toluene solution containing 0.1 mol of intermediate M6-3 was added to a 1000 mL three-necked flask. Stirring was started, and the system was cooled to -40 °C. 75 mL of a 1.6 mol / L sec-butyllithium solution in n-hexane was added dropwise to obtain the reaction solution. The reaction solution was slowly heated to 50 °C and stirred for 2 hours, then cooled to -10 °C, and 0.15 mol of phosphorus trichloride was added dropwise. After the addition was complete, the temperature was raised to 80 °C and the reaction was continued for 1 hour. 5.1 g of sublimed sulfur was added, and the reaction was continued for another hour. The temperature was lowered again to -40 °C, and 0.6 mol of AlCl3 and 0.36 mol of DIEA were added. The temperature was then raised to 110 °C, and the reaction was continued for 12 hours until complete. The reaction solution was cooled to room temperature and concentrated. The residue was purified by silica gel column chromatography using petroleum ether and dichloromethane in a volume ratio of 5:1. Intermediate M6 was obtained, weighing 31 g, with a yield of 64% and an HPLC purity of 98%.

[0064] Step 4, Synthesis of intermediate M7: Under nitrogen protection, 0.05 mol of intermediate M6 and 200 mL of dichloromethane were added to a 500 mL three-necked flask. Stirring was started, and the system was cooled to -15 °C. 0.05 mol of m-chloroperoxybenzoic acid was slowly added, and the reaction was allowed to proceed for 1 h until complete, yielding a reaction solution. The reaction solution was transferred to room temperature, and 20.0 mL of saturated sodium sulfite aqueous solution was added. The mixture was stirred for 1 h, and insoluble matter was removed. The solution was separated from the solvent by vacuum distillation. The residue was then subjected to silica gel column chromatography. The solvent used was petroleum ether and dichloromethane in a volume ratio of 3:1, yielding intermediate M7, weighing 8.2 g, with a yield of 61% and an HPLC purity of 99%.

[0065] Step 5, Synthesis of Intermediate 61-1: The synthesis method of intermediate 1-1 in Example 1 was followed, except that intermediate M2 was replaced with intermediate M7 to obtain intermediate 61-1; totaling 10.3g, yield 72.5%, and HPLC content 98%.

[0066] Step 6: Synthesis of asymmetric triterpenoids: The synthesis method of compound 1 in Example 1 was followed, except that intermediate 1-1 was replaced with intermediate 61-1 to obtain compound 61; the total yield was 5.3 g, the yield was 73.1%, the HPLC purity was 99%, and the LC-MS showed a molecular weight of 723.3.

[0067] 1H NMR data for compound 61: 1 H NMR (500 MHz, (CH3)2SO) δ 7.56-7.31 (m,15H), 7.24 (d, J = 5.0 Hz, 4H), 7.06 (dd, J = 34.3, 15.7 Hz, 7H), 6.83 (s,2H), 4.87 (s, 1H), 4.66 (s, 1H).

[0068] Example 6 The synthetic method for asymmetric triterpenoids is shown below, with the specific synthetic route as follows: .

[0069] Step 1, Synthesis of intermediate M8: Under nitrogen protection, 0.05 mol of intermediate M6, 200 mL of o-xylene, and 0.25 mol of triethylphosphine were added to a 500 mL three-necked flask. The mixture was stirred and heated to 130 °C for 48 h. After the reaction was completed, the mixture was cooled to room temperature, and excess o-xylene and triethylphosphine were removed by vacuum distillation to obtain intermediate M8, totaling 21.4 g, with a yield of 93.5% and an HPLC purity of 96%.

[0070] Step 2, Synthesis of Intermediate 109-1: The synthesis method of intermediate 1-1 in Example 1 was followed, except that intermediate M2 was replaced with intermediate M8 to obtain intermediate 109-1; totaling 10.1 g, yield 71.3%, HPLC content 98%.

[0071] Step 3: Synthesis of asymmetric triterpenoids: The synthesis method of compound 1 in Example 1 was followed, except that intermediate 1-1 was replaced by intermediate 109-1, and phenylboronic acid shown in formula b1 was replaced by 2,4-tert-butylphenylboronic acid shown in formula b4, to obtain compound 109; total amount 5.9g, yield 71.7%, HPLC purity 99%, LC-MS showed molecular weight 819.6.

[0072] 1H NMR data for compound 109: 1H NMR (500 MHz, (CH3)2SO ) δ 7.70 (s, 2H),7.61 (s, 1H), 7.52 (s, 1H), 7.45 (dd, J = 19.3, 4.2 Hz, 4H), 7.33 (d, J = 9.5Hz, 3H), 7.20 (d, J = 10.0 Hz, 4H), 7.10 – 6.93 (m, 7H), 6.90 (s, 2H), 6.63(s, 2H), 4.82 (d, J = 25.9 Hz, 2H), 1.32 (s, 18H).

[0073] Example 7 The synthetic method for asymmetric triterpenoids is shown below, with the specific synthetic route as follows: .

[0074] Step 1, Synthesis of intermediate M9: Under nitrogen protection, 150 mL of a tert-butylbenzene solution containing 0.05 mol of intermediate M6-3 was added to a 500 mL three-necked flask. Stirring was started, and the system was cooled to -40 °C. 40 mL of a 2.5 mol / L tert-butyllithium solution in n-hexane was added dropwise to obtain the reaction solution. The reaction solution was heated to 50 °C and stirred for 1 hour. The reaction was then stopped, and the reaction solution was concentrated at low temperature to remove low-boiling-point n-hexane. The reaction solution was cooled again to -40 °C, and 0.15 mol of trichloromethylsilane was added. The reaction solution was transferred to room temperature and reacted for 1 hour. 0.12 mol of DIEA was added dropwise at room temperature. After the addition was complete, the reaction solution was slowly heated to 160 °C and the reaction was continued for 18 hours until the reaction was complete. After the reaction was completed, the reaction solution was cooled to room temperature and concentrated. The residue was purified by silica gel column chromatography. The solvent used was petroleum ether and dichloromethane, with a volume ratio of 5:1. Intermediate M9 was obtained, weighing 13.2 g, with a yield of 57.6% and an HPLC purity of 98%.

[0075] Step 2, Synthesis of Intermediate 77-1: The synthesis method of intermediate 1-1 in Example 1 was followed, except that intermediate M2 was replaced with intermediate M9 to obtain intermediate 77-1; totaling 10.3g, yield 71.5%, HPLC content 98%.

[0076] Step 3: Synthesis of asymmetric triterpenoids: The synthesis method of compound 1 in Example 1 was followed, except that intermediate 1-1 was replaced with intermediate 77-1 to obtain compound 77; the total yield was 6.9 g, the yield was 71.4%, the HPLC purity was 99%, and the LC-MS showed a molecular weight of 719.3.

[0077] 1H NMR data for compound 77: 1 H NMR (500 MHz, (CH3)2SO) δ 7.61 (s, 1H), 7.54– 7.31 (m, 12H), 7.25 (d, J = 15.0 Hz, 4H), 7.15 (s, 2H), 7.12 – 6.96 (m,7H), 6.73 (s, 2H), 4.84 (s, 1H), 4.59 (s, 1H), 0.66 (s, 3H).

[0078] Example 8 The synthetic method for asymmetric triterpenoids is shown below, with the specific synthetic route as follows: .

[0079] Step 1: Synthesis of intermediate M10: Under nitrogen protection, 120 mL of a tert-butylbenzene solution containing 0.03 mol of intermediate M6-3 was added to a 500 mL three-necked flask. Stirring was started, and the system was cooled to -40 °C. 48 mL of a 2.5 mol / L tert-butyllithium solution in n-hexane was added dropwise. The reaction solution was heated to 50 °C and stirred for 1 hour. The reaction was stopped, and the reaction solution was concentrated at low temperature to remove low-boiling-point n-hexane. The reaction solution was cooled again to -40℃, and 0.12 mol of germanium tetrachloride was added. The reaction solution was then slowly heated to 160℃ and reacted for 18 h until the reaction was complete. The reaction solution was then cooled to 0℃, and 150 mL of 1.2 mol / L lithium methyl ether solution was added dropwise. After the addition was complete, the reaction solution was transferred to room temperature and reacted for 1 h. After the reaction was completed, the solution was filtered with magnesium silicate, and the eluent was dichloromethane. The solvent was removed by vacuum distillation to obtain the crude product. The crude product was purified by silica gel column chromatography to obtain intermediate M10; totaling 12.7 g, yield 49.2%, HPLC purity 98%.

[0080] Step 2, Synthesis of Intermediate 98-1: The synthesis method of intermediate 1-1 in Example 1 was followed, with the difference that intermediate M2 was replaced by intermediate M10 and intermediate M1-2 was replaced by compound M1 to obtain 98-1; totaling 11.6 g, yield 71.3%, HPLC content 98%.

[0081] Step 3: Synthesis of asymmetric triterpenoids: The synthesis method of compound 1 in Example 1 was followed, except that 4-bromo-1,3-dicyanobenzene (as shown in formula b2) was used to replace intermediate 1-1, and intermediate 98-1 was used to replace phenylboronic acid (as shown in formula b1) to obtain compound 98; total yield was 5.8 g, yield was 70.9%, HPLC purity was 99%, and LC-MS showed a molecular weight of 814.8.

[0082] Example 9 The synthetic method for asymmetric triterpenoids is shown below, with the specific synthetic route as follows: .

[0083] Step 1: Synthesis of intermediate M11: Under nitrogen protection, 150 mL of a tert-butylbenzene solution containing 0.05 mol of intermediate M6-3 was added to a 500 mL three-necked flask. Stirring was started, and the system was cooled to -40 °C. 40 mL of a 2.5 mol / L tert-butyllithium solution in n-hexane was added dropwise to obtain the reaction solution. The reaction solution was heated to 50 °C and stirred for 2 hours, then the reaction was stopped. The reaction solution was cooled to -40 °C, 0.2 mol of bismuth trichloride was added, and the mixture was transferred to room temperature for 1 hour. Then, 0.12 mol of DIEA was added dropwise at room temperature. After the addition was complete, the reaction solution was slowly heated to room temperature and the reaction was continued for 15 hours until the reaction was complete. After the reaction was complete, the reaction solution was concentrated, and the residue was purified by silica gel column chromatography. The solvent used was petroleum ether and dichloromethane, with a volume ratio of petroleum ether to dichloromethane of 5:1, to obtain intermediate M11; weight 12.1 g, yield 53.0%, HPLC purity 98%.

[0084] Step 2, Synthesis of Intermediate 102-1: The synthesis method of intermediate 1-1 in Example 1 was followed, except that intermediate M11 was used to replace intermediate M2, and compound M1 was used to replace M1-2, to obtain intermediate 102-1; totaling 12.0 g, yield 70.6%, HPLC content 98%.

[0085] Step 3: Synthesis of asymmetric triterpenoids: The synthesis method of compound 1 in Example 1 was followed, except that 4-bromo-1,3-dicyanobenzene as shown in formula b2 was used to replace intermediate 1-1, and intermediate 102-1 was used to replace phenylboronic acid as shown in formula b1, resulting in 5.8 g of compound 102, with a yield of 71.2%, an HPLC purity of 99%, and a molecular weight of 847.3 as shown by LC-MS.

[0086] Example 10 The synthetic method for asymmetric triterpenoids is shown below, with the specific synthetic route as follows: .

[0087] Step 1: Synthesis of intermediate M11: Under nitrogen protection, 150 mL of a tert-butylbenzene solution containing 0.05 mol of intermediate M6-3 was added to a 500 mL three-necked flask. Stirring was started, and the system was cooled to -40 °C. 40 mL of a 2.5 mol / L tert-butyllithium solution in n-hexane was added dropwise to obtain the reaction solution. The reaction solution was heated to 50 °C and stirred for 1 hour, then the reaction was stopped. The reaction solution was cooled again to -40 °C, and 0.2 mol of trichlorophenyltinane was added. The mixture was then transferred to room temperature and reacted for 2 hours. 0.12 mol of DIEA was added dropwise at room temperature. After the addition was complete, the reaction solution was slowly heated to 60 °C and reacted for 2 hours until the reaction was complete. After the reaction was complete, the reaction solution was concentrated, and the residue was purified by silica gel column chromatography. The solvent used was petroleum ether and dichloromethane, with a volume ratio of 5:1, to obtain intermediate M11, weighing 10.0 g, with a yield of 32.1% and an HPLC purity of 98%.

[0088] Step 2, Synthesis of Intermediate 105-1: The synthesis method of intermediate 1-1 in Example 1 was followed, with the difference that 0.015 mol of intermediate M12 was used to replace 0.02 mol of intermediate M2, and 0.015 mol of compound M1 was used to replace 0.02 mol of intermediate M1-2, to obtain intermediate 105-1, totaling 9.6 g, with a yield of 69.3% and an HPLC purity of 98%.

[0089] Steps for the synthesis of asymmetric triterpenoids: The synthesis method of compound 1 in Example 1 was followed, except that 4-bromo-1,3-dicyanobenzene (as shown in formula b2) was used to replace intermediate 1-1, and intermediate 105-1 was used to replace phenylboronic acid (as shown in formula b1) to obtain compound 105; total yield was 6.5 g, yield was 70.2%, HPLC purity was 99%, and LC-MS showed a molecular weight of 923.2.

[0090] 1H NMR data for compound 105: 1 H NMR (500 MHz, (CH3)2SO) δ 8.32-8.00 (m,3H), 7.49 (dd, J = 11.4, 6.7 Hz, 4H), 7.40-7.30 (m, 4H), 7.20 (d, J = 35.0Hz, 4H), 7.11-6.96 (m, 7H), 6.90 (s, 2H), 6.63 (s, 2H), 4.93 (s, 1H), 4.41 (s, 1H).

[0091] Example 11 The synthetic method for asymmetric triterpenoids is shown below, with the specific synthetic route as follows: .

[0092] Step 1, Synthesis of intermediate M13-1: Under nitrogen protection, 0.1 mol of 2,5-dibromo-1,3-difluorobenzene (formula a1), 0.1 mol of 3,3'-oxydiphenol (formula a26), 0.3 mol of cesium carbonate, 0.015 mol of trans-1,2-cyclohexanediamine, 0.02 mol of CuI, and 500 mL of N,N-dimethylformamide were added to a 1000 mL three-necked flask. The mixture was stirred for 30 minutes and then refluxed at 130 °C for 2 days to obtain a reaction solution. The reaction solution was cooled to room temperature and filtered. The filtrate was distilled under reduced pressure to obtain a residue, which was purified by silica gel column chromatography. The solvent used was petroleum ether and dichloromethane in a volume ratio of 10:1, yielding intermediate M13-1, weighing 24.4 g, with a yield of 56.1% and an HPLC purity of 98%.

[0093] Step 2, Synthesis of intermediate M13: The synthesis method of intermediate M9 in Example 7 was used, except that intermediate M13-1 was used instead of intermediate M6-3 to obtain intermediate M13; weight 11.5g, yield 58.3%, HPLC content 98%.

[0094] Step 3, Synthesis of Intermediate 87-1: The synthesis method of intermediate 1-1 in Example 1 was followed, except that intermediate M2 was replaced by intermediate M13 to obtain intermediate 87-1; totaling 9.3g, yield 71.5%, HPLC content 98%.

[0095] Step 4: Synthesis of asymmetric triterpenoids: The synthesis method of compound 1 in Example 1 was followed, except that intermediate 1-1 was replaced by intermediate 87-1, and phenylboronic acid shown in formula b1 was replaced by 2,4-tert-butylphenylboronic acid shown in formula b6, to obtain compound 87; total yield was 5.5 g, yield was 72.1%, HPLC purity was 99%, and LC-MS showed a molecular weight of 757.0.

[0096] 1H NMR data for compound 87: 1H NMR (500 MHz, (CH3)2SO)2δ 7.73 (s, 2H), 7.57(d, J = 17.7 Hz, 2H), 7.49 (dd, J = 6.6, 3.8 Hz, 4H), 7.44-7.29 (m, 5H), 7.15(s, 2H), 7.04 (s, 2H), 6.79 (s, 4H), 4.85 (d, J = 13.9 Hz, 2H), 1.32 (s,18H), 0.66 (s, 3H).

[0097] The synthesis of other compounds follows the same method as the compounds described above, except that the corresponding a1 to a2 are used. 27 Reactants a and b1~b 21 The reactant b can be replaced. The reactant composition of some compounds in this invention is shown in Table 1:

[0098] Table 1. Reactant composition of some compounds in this invention Note: All basic reactants of all compounds involve reactant a1, which is not shown in the table.

[0099] Electroluminescent devices were fabricated using asymmetric triterpenoid compounds as guest light-emitting materials. A schematic diagram of the electroluminescent device structure is shown below. Figure 1 As shown, the device includes a substrate 1 and, sequentially stacked on the substrate 1, an anode layer 2, a hole injection layer 3, a hole transport layer 4, an electron blocking layer 5, a light-emitting layer 6, a hole blocking layer 7, an electron transport layer 8, an electron injection layer 9, a cathode layer 10, and a capping layer 11. The electroluminescent device is fabricated using currently recognized device fabrication technology in the industry.

[0100] The chemical structures of some of the materials used in the fabrication of electroluminescent devices are as follows: .

[0101] Application Example 1 The method for fabricating an electroluminescent device includes the following steps: Under high vacuum conditions, on the cleaned conductive glass 1, a 25 nm thick indium tin oxide layer 2 was sequentially deposited as an anode layer, a 10 nm thick mixture of compounds HT1 and P1 as a hole injection layer 3, a 50 nm thick compound HT-1 as a hole transport layer 4, and a 10 nm thick EB-1 as an electron blocking layer 5. After the electron blocking layer 5 was deposited, a 30 nm thick light-emitting layer 6 was deposited. The light-emitting layer 6 used compound PH-4 as the host light-emitting material and compound 1 synthesized in Example 1 as the guest light-emitting material. The mass ratio of the host light-emitting material to the guest light-emitting material was 97:3, and the mass ratio of compound HT1 to compound P1 was 97:3.

[0102] The following layers are deposited sequentially on the light-emitting layer 6: a 16 nm thick compound HB-1 as a hole blocking layer 7, a 25 nm thick compound E1 as an electron transport layer 8, a 10 nm thick lithium 8-hydroxyquinoline layer as an electron injection layer 9, and a 50 nm thick Al electrode layer as a cathode layer 10. Finally, the cover layer material X is deposited and then encapsulated to obtain the electroluminescent device, denoted as Ex.1.

[0103] Application Example 2 The preparation method of the electroluminescent device is basically the same as that of the preparation method in Application Example 1, except that: compound 17 synthesized in Example 2 is used as the guest luminescent material; and the mass ratio of the host luminescent material to the guest luminescent material is 99:1, and the electroluminescent device is obtained, denoted as Ex.2.

[0104] Application Example 3 The preparation method of the electroluminescent device is basically the same as that of the preparation method in Application Example 1, except that: compound 37 synthesized in Example 3 is used as the guest luminescent material; and the mass ratio of the host luminescent material to the guest luminescent material is 98:2, and the electroluminescent device is obtained, denoted as Ex.3.

[0105] Application Example 4 The preparation method of the electroluminescent device is basically the same as that of Application Example 1, except that the guest light-emitting material is different. According to the substitution relationship shown in Table 2, the corresponding electroluminescent devices are prepared in sequence, denoted as Ex.4, Ex.5, Ex.6, Ex.7, Ex.8, Ex.9, Ex.10, Ex.11, Ex.12, Ex.13, Ex.14, Ex.15, Ex.16, Ex.17, Ex.18, Ex.19, Ex.20, Ex.21, Ex.22, Ex.23, Ex.24, Ex.25, Ex.26, Ex.27, Ex.28, Ex.29, Ex.30, Ex.31, Ex.32, Ex.33, Ex.34, Ex.35, Ex.36, Ex.37, Ex.38, Ex.39, Ex.40, Ex.41 and Ex.42.

[0106] Table 2. Different compounds used in the guest light-emitting materials of the electroluminescent devices in Application Example 4 Application Comparative Example 1 The method for fabricating an electroluminescent device includes the following steps: Under high vacuum conditions, on the cleaned conductive glass, a 25 nm thick indium tin oxide layer is deposited sequentially as an anode layer 2, a 10 nm thick mixture of compounds HT1 and P1 as a hole injection layer 3, a 50 nm thick compound HT-1 as a hole transport layer 4, and a 10 nm thick compound EB-1 as an electron blocking layer 5. After the electron blocking layer 5 is deposited, a 30 nm thick light-emitting layer 6 is deposited. The light-emitting layer 6 uses compound PH-4 as the host light-emitting material and compound I from the patent application number 201980062456.1 as the guest light-emitting material. The mass ratio of the host light-emitting material to the guest light-emitting material is 98:2, and the mass ratio of compound HT1 to compound P1 is 97:3.

[0107] A 16 nm thick compound HB-1 was deposited sequentially on the light-emitting layer 6 as a hole-blocking layer 7, a 25 nm thick compound E1 as an electron transport layer 8, a 10 nm thick lithium 8-hydroxyquinoline layer as an electron injection layer 9, and a 50 nm thick Al electrode layer as a cathode layer 10. Finally, a capping layer material X was deposited and the device was encapsulated to obtain an electroluminescent device. This method yields devices such as... Figure 1 The electroluminescent device shown.

[0108] Application Comparative Example 2 The preparation method of the electroluminescent device is basically the same as that of Comparative Example 1, except that the light-emitting layer is different. The light-emitting layer is obtained by using compound PH-4 as the main light-emitting material and compound II from the patent application with application number 202210290018.4 as the guest light-emitting material.

[0109] Application Comparative Example 3 The preparation method of the electroluminescent device is basically the same as that of Comparative Example 1, except that the light-emitting layer is different. The light-emitting layer is obtained by using compound PH-4 as the main light-emitting material and compound M38 from the patent application number 202310367273.9 as the guest light-emitting material.

[0110] Table 3 Performance data of the electroluminescent devices prepared in Comparative Examples 1-3 and Application Examples 1-4 Note: "T95" indicates the time it takes for the brightness of an electroluminescent device to decay to 95% of its initial brightness.

[0111] As can be seen from the data in Table 3, compared with electroluminescent devices prepared using compounds I, II, and M38 in the prior art as guest luminescent materials, the electroluminescent devices prepared using the asymmetric tripterene compounds synthesized in the embodiments of the present invention as guest luminescent materials exhibit significantly narrower full width at half maximum (FWHM), significantly longer lifespan, and significantly improved current efficiency. Furthermore, the electroluminescent devices prepared using the asymmetric tripterene compounds of the embodiments of the present invention as guest luminescent materials have emission wavelengths in the violet to visible light range, meeting the application requirements of the devices in different scenarios.

[0112] The data from the electroluminescent devices Ex.1 to Ex.3 show that when the mass of the guest light-emitting material in the light-emitting layer is in the range of 1% to 3%, the overall luminous efficiency of the electroluminescent devices is similar; when the mass of the guest light-emitting material is 2%, the luminous performance of the prepared electroluminescent device is slightly better than that of Example 1 and Example 2.

[0113] In summary, when the asymmetric triterpenoid compounds described in this invention are used as guest luminescent materials in the luminescent layer of OLEDs, they can effectively reduce the full width at half maximum (FWHM) of OLED devices and improve the luminous efficiency and lifespan of OLED devices.

[0114] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

[0115] Many other changes and modifications can be made without departing from the concept and scope of this invention. It should be understood that this invention is not limited to the specific embodiments, and the scope of this invention is defined by the appended claims.

Claims

1. An asymmetric triterpenoid compound, characterized in that, The structural formulas of the asymmetric triterpenoid compounds are shown in general formula 1, general formula 2, general formula 3 or general formula 4: ； Z1, Z2 and Z3 are independently selected from C-R0 or N, and R0 is selected from H, D, F, cyano, trifluoromethyl, C1-C6 alkyl or phenyl; R1 and R2 are each independently selected from H, D, F, cyano, trifluoromethyl, C1-C6 alkyl or phenyl; X is selected from O, S, or NR. 11 ; M1 is selected from B, P, P=O, P=S, and Si-R. 12 Ge-R 13 Sn-R 14 Or Sb; R3 to R5 are each independently selected from H, methyl, ethyl, isopropyl, or tert-butyl. R8~R 10 Each is independently selected from H, methyl, ethyl, isopropyl, or tert-butyl; R is selected from C6~C 20 Aryl groups.

2. The asymmetric triterpenoid compound according to claim 1, characterized in that, R is phenyl, 4-tert-butylphenyl, naphthyl, biphenyl, or 9,9-dimethylfluorenyl.

3. The asymmetric triterpenoid compound according to claim 1, characterized in that, Z1, Z2, and Z3 are all C-R0, where R0 is selected from H, D, F, cyano, trifluoromethyl, methyl, ethyl, tert-butyl, phenyl, or deuterated methyl; R1 and R2 are each independently selected from H, D, F, cyano, trifluoromethyl, methyl, tert-butyl, phenyl, deuterated methyl, or deuterated tert-butyl. Alternatively, Z1 and Z3 are both N, R1 and R2 are both selected from phenyl, and R0 is selected from H; Alternatively, Z1, Z2, and Z3 are all N, and R1 and R2 are both selected from phenyl groups.

4. The asymmetric triterpenoid compound according to claim 1, characterized in that, R 11 It is selected from phenyl, 4-methylphenyl, 4-isopropylphenyl or 4-tert-butylphenyl.

5. The asymmetric triterpenoid compound according to claim 1, characterized in that, R 12 ~R 14 Each is independently selected from phenyl, methyl, ethyl, propyl, or butyl.

6. The asymmetric triterpenoid compound according to claim 1, characterized in that, The asymmetric triterpenoid compound is selected from one of the following compounds: 。 7. An electroluminescent device, comprising an anode layer, a hole transport layer, a light-emitting layer, an electron transport layer, and a cathode layer stacked sequentially, characterized in that, The light-emitting layer is prepared from a host light-emitting material and a guest light-emitting material, wherein the guest light-emitting material is an asymmetric triterpenoid compound as described in any one of claims 1 to 7.

8. The electroluminescent device according to claim 7, characterized in that, The mass of the luminescent material is 1% to 3% of the mass of the luminescent layer.

9. The electroluminescent device according to claim 7, characterized in that, The host luminescent material is selected from one of the following compounds: 。

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