A material with electron transport function, an organic electroluminescent device, and its application.

Abstract

This invention belongs to the field of organic electroluminescent materials technology. It discloses a material with electron transport function, an organic electroluminescent device, and its application. The compound structure of the material with electron transport function has 9-alkyl-9-phenylfluorenyl, dibenzofuran, and triazine groups linked together. The overall molecular structure has formed a strong D-π-A (donor-bridge-acceptor) system, which gives the compound good electron transport function. When used in organic electroluminescent devices, it has low driving voltage, high luminous efficiency, and long service life.

Description

Technical Field

[0001] This invention belongs to the field of organic electroluminescent materials technology, and more specifically, relates to a material with electron transport function, an organic electroluminescent device, and its application. Background Technology

[0002] Organic light-emitting diodes (OLEDs) have a sandwich-like structure, consisting of electrode material layers and organic functional materials sandwiched between different electrode layers or independently. These various functional materials are stacked together according to their intended use to form the OLED. As a current-carrying device, when a voltage is applied to the two electrodes of the OLED, positive and negative charges are generated in the organic functional material layers through the action of an electric field. These charges then recombine in the light-emitting layer, producing light; this process is called electroluminescence. Research on improving the performance of OLEDs includes reducing the driving voltage, increasing the luminous efficiency, and extending the device's lifespan. To continuously improve the performance of OLEDs, innovation in not only the structure and fabrication process of OLEDs is needed, but also continuous research and innovation in organic electroluminescent functional materials to create higher-performance organic electroluminescent functional materials.

[0003] In organic functional layers, the electron transport layer and hole blocking layer play a crucial role in device performance, especially efficiency and lifetime. The primary function of the electron transport layer is to effectively receive electrons from the cathode and transport them to the emissive layer. Ideal electron transport materials should possess high electron mobility, suitable energy levels to lower the electron injection barrier, good thin-film formation capabilities, and chemical compatibility with adjacent layers. The hole blocking layer is typically placed between the emissive layer and the electron transport layer. Its core function is to utilize its higher lowest unoccupied molecular orbital energy level or higher ionization potential to prevent holes from the anode side from excessively migrating to the electron transport layer or cathode, thereby confining the holes within the emissive layer and increasing the probability of electron-hole recombination within it. This helps to widen the recombination region, reduce exciton quenching in non-emissive regions, and thus improve the device's luminous efficiency, color purity, and stability.

[0004] However, blue organic light-emitting diodes (OLEDs) have been a weak point in the development of full-color OLEDs, and their efficiency and lifetime performance have remained difficult to improve comprehensively. Therefore, developing novel electron transport functional materials with higher electron mobility, better energy level tunability, superior thermal / morphological / electrochemical stability, and potential multifunctional integration properties has become one of the key technological breakthroughs for improving the overall performance of blue organic optoelectronic devices and promoting their commercialization. Summary of the Invention

[0005] The main objective of this invention is to provide a highly efficient and stable compound with electron transport function. The compound's structure is mainly composed of 9-alkyl-9-phenylfluorenyl, dibenzofuran, and triazine groups. It can be used as an electron transport layer and hole blocking layer in organic electroluminescent devices, giving the device excellent characteristics such as low driving voltage, high luminous efficiency, and long service life.

[0006] To achieve the above objectives, the first objective of this invention is to provide a material with electronic transport functionality, employing the following technical solution:

[0007] A material with electron transport function, wherein the material with electron transport function has the general structural formula shown in chemical formula I:

[0008] ;

[0009] in,

[0010] R is independently selected from substituted or unsubstituted C1-C8 alkyl groups;

[0011] Ar1 and Ar2 are independently selected from hydrogen, deuterium, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, wherein the heteroatom contains at least one of O, S, N, Si, and Se;

[0012] Ar3 and Ar4 are independently selected from substituted or unsubstituted C6-C30 aryl and substituted or unsubstituted C3-C30 heteroaryl, respectively, wherein the heteroatom contains at least one of O, S, N, Si, and Se;

[0013] R1, R2, and R3 are independently selected from hydrogen and deuterium, respectively;

[0014] n1 and n3 are independently selected from 0, 1, 2, 3, and 4;

[0015] n2 is independently selected from 0, 1, 2, and 3;

[0016] In the chemical formula I, any hydrogen atom can be independently replaced by deuterium.

[0017] Furthermore, chemical formula I has the following structures: chemical formulas IA~IB:

[0018] .

[0019] Furthermore, R is independently selected from substituted or unsubstituted methyl, substituted or unsubstituted ethyl, substituted or unsubstituted propyl, substituted or unsubstituted isopropyl, and substituted or unsubstituted tert-butyl.

[0020] Furthermore, Ar1 and Ar2 are independently selected from hydrogen, deuterium, substituted or unsubstituted C6-C12 aryl, substituted or unsubstituted C5-C18 heteroaryl, wherein the heteroatom contains at least one of O, S, N, Si, and Se.

[0021] Furthermore, Ar3 and Ar4 are independently selected from substituted or unsubstituted C6-C20 aryl groups and substituted or unsubstituted C5-C18 heteroaryl groups, respectively, wherein the heteroatom contains at least one of O, S, N, Si, and Se.

[0022] Furthermore, Ar1 and Ar2 are independently selected from hydrogen, deuterium, and the following structures:

[0023]

[0024] In the above substituents, any H can be independently substituted by deuterium.

[0025] Furthermore, Ar3 and Ar4 are each independently selected from the following structures:

[0026]

[0027] In the above substituents, any H can be independently substituted by deuterium;

[0028] * indicates the linking site of a functional group.

[0029] Further, the term "substituted or unsubstituted" means substituted with one, two or more substituents selected from the following: deuterium, cyano, halogen, methyl, ethyl, propyl, butyl, tert-butyl, cyclopentane, cyclohexane, phenyl, biphenyl, naphthyl, fluorenyl, dimethylfluorenyl, phenanthrene, triphenylene, carbazolyl, furanyl, thiophene, pyrrole, pyridyl, benzofuranyl, benzothiophene, isobenzofuranyl, dibenzofuranyl, dibenzothiophene, or substituted with two or more substituents linked together from the substituents shown above, or without substituents.

[0030] Furthermore, the chemical formula I has any one of the structures of compounds 1-736:

[0031] .

[0032] A second objective of this invention is to provide a method for preparing the material as described above.

[0033] It should be noted that the material with electron transport function in this invention can be prepared by methods known to those skilled in the art. Alternatively, the following reaction process is preferred for preparation, and the specific operation is as follows:

[0034] Step 1 specifically includes the following processes:

[0035] Cool to -78℃, add THF to the reaction flask, then add raw material B (1.1-1.5 eq) dissolved in it, replace with nitrogen three times, stir for 10-30 min, slowly add n-butyllithium (1.1-1.5 eq) to the reaction flask, react for 1-4 h, dissolve raw material A (1.0 eq) in tetrahydrofuran, then slowly add the solution of raw material A dropwise to the reaction flask, stir until homogeneous, stop cooling, and continue the reaction at room temperature for 2-18 h. Detect the reaction using thin-layer chromatography. After the reaction is complete, wash three times with water, retain the organic phase, then extract the aqueous phase with dichloromethane, combine the organic phases and concentrate, and purify the intermediate 1 by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:2-1:6).

[0036] Step 2 specifically includes the following processes:

[0037] Dichloromethane was added to the reaction flask, followed by intermediate 1 (1.0 eq) dissolved therein. Triethylsilane (1.1-2.0 eq) was added while stirring at -10℃. After stirring for 15-60 min, methanesulfonic acid (2.0-4.0 eq) was added and stirring was continued for 10-30 min. The mixture was then transferred to room temperature and reacted for 1-4 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, water was added to the reaction solution and stirred. The mixture was extracted and separated, retaining the organic phase. The aqueous phase was then extracted with dichloromethane. The organic phases were combined and concentrated. Intermediate 2 was obtained by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:4-1:12) or pure petroleum ether.

[0038] Step 3 specifically includes the following processes:

[0039] THF was added to the reaction flask, followed by intermediate 2 (1.0 eq) dissolved in it. The mixture was stirred at room temperature until dissolved. Then, t-BuOK (2.0-10.0 eq) was slowly added to the reaction flask. After stirring for 1 h, starting material C (3.0-8.0 eq) was slowly added dropwise. The temperature was raised to 70-90℃, and the reaction was carried out for 6-20 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the temperature was lowered slightly, and the mixture was filtered with diatomaceous earth to remove salts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Intermediate 3 was obtained by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:4-1:12).

[0040] Step 4 specifically includes the following processes:

[0041] Intermediate 3 (1.0 eq), pinacol diborate (1.0-1.5 eq), and potassium acetate (2.0-4.0 eq) were added to a reaction flask, followed by 1,4-dioxane. Nitrogen gas was purged, and tris(dibenzylacetone)dipalladium (0.02-0.10 eq) and X-Phos (0.1-0.2 eq) were added under nitrogen protection. The mixture was then heated to 110-120 °C and refluxed for 2-30 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the temperature was slightly lowered, and the mixture was filtered with diatomaceous earth to remove salts and catalysts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Intermediate 4 was obtained by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:3-1:10).

[0042] Step 5 specifically includes the following processes:

[0043] Intermediate 4 (1.0 eq) and starting material D (1.0-1.3 eq) were added to a reaction flask, followed by a mixed solution of toluene, ethanol, and water (V:V:V = 3:1:1). Nitrogen gas was introduced, and under nitrogen protection, tetrakis(triphenylphosphine)palladium (0.01-0.05 eq) and potassium carbonate (2.0-4.0 eq) or palladium acetate (0.02-0.06 eq), X-Phos (0.1-0.3 eq) and cesium carbonate (2.0-4.0 eq) were added. The mixture was then heated to 80℃-100℃ and refluxed for 2-30 h. The mixture was filtered with diatomaceous earth to remove salts and catalysts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Intermediate 5 was obtained by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V = 1:3-1:10).

[0044] Note: In this reaction step, the starting material D contains two halogens. This is achieved by utilizing the characteristic of reactivity I > Br > Cl in the Suzuki coupling reaction, and by controlling the reaction conditions and reaction sites. The intermediate containing the target structure was then prepared. The reaction was purified by column chromatography or through a silica gel funnel to remove byproducts and obtain the target compound. For the reaction mechanism, please refer to:

[0045] Organometallic Chemistry (6th Edition), Robert H. Crabtree, published by East China University of Science and Technology Press, Shanghai, September 00, 2017, ISBN: 978-7-5628-5111-0, page 388.

[0046] Organic Chemistry and Optoelectronic Materials Experiment Tutorial, Chen Runfeng, Publisher: Southeast University Press, Publication Date: 2019-11-00, ISBN: 9787564184230, Page 174.

[0047] Step 6 specifically includes the following processes:

[0048] Intermediate 5 (1.0 eq), pinacol diborate (1.0-1.5 eq), and potassium acetate (2.0-4.0 eq) were added to a reaction flask, followed by 1,4-dioxane. Nitrogen gas was introduced, and under nitrogen protection, tris(dibenzylacetone)dipalladium (0.02-0.10 eq) and X-Phos (0.1-0.2 eq) were added. The mixture was then heated to 110-120 °C and refluxed for 2-30 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the temperature was slightly lowered, and the mixture was filtered with diatomaceous earth to remove salts and catalysts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Intermediate 6 was obtained by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:3-1:10).

[0049] Step 7 specifically includes the following processes:

[0050] Intermediate 6 (1.0 eq) and raw material E (1.0-1.3 eq) were added to a reaction flask, followed by a mixed solution of toluene, ethanol, and water (V:V:V = 3:1:1). Nitrogen gas was purged, and under nitrogen protection, tetrakis(triphenylphosphine)palladium (0.01-0.05 eq) and potassium carbonate (2.0-4.0 eq) or palladium acetate (0.02-0.06 eq), X-Phos (0.1-0.3 eq) and cesium carbonate (2.0-4.0 eq) were added. The mixture was then heated to 80-100°C and refluxed for 2-30 hours. The mixture was filtered with diatomaceous earth to remove salts and catalysts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. The solution was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V = 1:3-1:10) to obtain chemical formula I.

[0051] The specific synthesis route is as follows:

[0052] .

[0053] Among them, R, R1-R3, n1-n3, Ar1-Ar4 are as defined in chemical formula I, and Hal1-Hal3 are selected from Cl, Br, and I.

[0054] The present invention also provides an organic electroluminescent device, the organic electroluminescent device comprising an anode, a cathode and an organic material layer disposed between the anode and the cathode, the organic material layer containing the aforementioned material having electron transport function.

[0055] In one embodiment of the present invention, the organic electroluminescent device includes an anode, a cathode, and an organic material layer disposed between the anode and the cathode, wherein the organic material layer contains a hole blocking layer, and the hole blocking layer is the material having electron transport function.

[0056] In one embodiment of the present invention, the organic electroluminescent device includes an anode, a cathode, and an organic material layer disposed between the anode and the cathode, wherein the organic material layer contains an electron transport layer, and the electron transport layer is the material having electron transport function.

[0057] It should be noted that the organic material layer of the organic electroluminescent device in this invention can be formed as a single-layer structure or as a multilayer structure with two or more organic material layers. For example, the organic electroluminescent device may have a structure comprising a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting auxiliary layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer as organic material layers. However, the structure of the organic electroluminescent device is not limited to this, and may include fewer or more organic material layers.

[0058] A third objective of this invention is to provide an application of a material with electron transport functionality, as described above, in an organic electroluminescent device.

[0059] Furthermore, the organic electroluminescent device can be used in organic electroluminescent apparatuses, including but not limited to flat panel displays, computer monitors, a medical monitor, a television set, billboards, a lamp for internal or external lighting and / or signaling, head-up displays, fully transparent or partially transparent displays, flexible displays, a laser printer, a telephone, a mobile phone, tablets, a photo album, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a microdisplay, a 3D display, a virtual reality or augmented reality display, vehicles, video walls comprising multiple displays tiled together, theater or stadium screens, phototherapy devices, and signs.

[0060] Beneficial effects of this invention:

[0061] The electron transport material provided by this invention has a strong D-π-A (donor-bridge-acceptor) system formed by the linkage of 9-alkyl-9-phenylfluorenyl, dibenzofuran and triazine in its compound structure. This gives the compound excellent electron transport properties, and when used in organic electroluminescent devices, it has low driving voltage, high luminous efficiency and long lifespan.

[0062] Specifically, firstly, fluorene has a certain electron-donating ability; at position 9 of fluorene, an sp... 3The hybrid carbon atom connects to alkyl and phenyl groups. This tetrahedral carbon atom acts as a "three-dimensional hub," ensuring that the phenyl group (connecting the triazine-dibenzofuran system) and the fluorene ring are perpendicular to each other, and the alkyl chain extends further outward, introducing significant three-dimensional steric hindrance throughout the molecule. In solid-state films, this structure effectively prevents π-π stacking between adjacent luminescent molecules, suppressing concentration quenching and exciton annihilation caused by excessive molecular proximity. More excitons can decay through radiative transitions (luminescence), thereby increasing quantum yield and resulting in higher current efficiency and external quantum efficiency. The large, rigid fluorene structure and the presence of the alkyl chain significantly increase the glass transition temperature of the molecule. During device fabrication and operation, the material is less prone to crystallization, forming a uniform and stable amorphous film, thus delaying performance degradation under long-term power-on heating and extending the device's lifespan.

[0063] Secondly, the dibenzofuran group acts as a bridging group between the triazine group and the 9-alkyl-9-phenylfluorenyl group (a phenyl group attached to the 9-position of fluorenyl). This bridging function can regulate the charge transfer between the donor and acceptor, leading to a more balanced charge transfer, which is beneficial for radiative transitions. Simultaneously, through spatial conjugation or π-extension, it may narrow the singlet-tritt band gap, improving exciton utilization and effectively increasing the device's luminescence efficiency. Furthermore, the introduction of a rigid planar dibenzofuran group can increase the glass transition temperature (Tg) of the molecule, reducing the tendency for crystallization in the thin film state, which helps to form a uniform amorphous thin film, reduces phase separation during device aging, and extends device lifetime.

[0064] Triazine is a strong electron-withdrawing group with a deep LUMO level. It can significantly lower the LUMO level of the molecule, enhancing electron injection and transport capabilities. Combined with the preceding donor-bridging moiety (fluorene-dibenzofuran), it forms a highly efficient D-π-A structure. This strong intramolecular charge transfer characteristic leads to a high degree of spatial separation between the HOMO and LUMO electron clouds. The matched HOMO / LUMO energy levels (higher HOMO in the donor moiety and lower LUMO in the acceptor moiety) lower the potential barriers for hole and electron injection from the anode and cathode, respectively, thereby reducing the device's driving voltage. This allows for carrier balance, resulting in higher external quantum efficiency and reducing efficiency degradation caused by polaron quenching or triplet-triplet annihilation at high current densities. The rigid triazine ring also helps to increase the material's thermal decomposition temperature and glass transition temperature, preventing crystallization or phase separation due to heat during device operation, thus extending device lifetime.

[0065] Furthermore, structures with cyano-substituted phenyl, biphenyl, or pyridyl groups can be introduced onto the triazine group. The introduced cyano group is one of the strongest known electron-withdrawing groups. The cyano group and triazine work together; the introduction of the cyano group further lowers the LUMO energy level of the triazine and even the entire molecule, resulting in stronger electron injection and transport capabilities. This type of compound, as an electron transport layer material, further enhances device performance. Specifically, when the triazine and 9-alkyl-9-phenylfluorene groups are attached to different benzene rings on the intermediate bridging dibenzofuran group, the device exhibits superior luminous efficiency; when attached to the same benzene ring on the dibenzofuran group, the device exhibits superior lifetime. Attached Figure Description

[0066] Figure 1 The image shows the 1H NMR spectrum of compound 1 prepared in Example 1.

[0067] Figure 2 The 1H NMR spectrum of compound 217 prepared in Example 2.

[0068] Figure 3 The 1H NMR spectrum of compound 637 prepared in Example 3. Detailed Implementation

[0069] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0070] Additionally, it should be noted that the values ​​given in the following embodiments are as accurate as possible. However, those skilled in the art will understand that due to unavoidable measurement errors and experimental issues, each number should be understood as an approximation rather than an absolutely accurate value.

[0071] Example 1

[0072]

[0073] Step 1 specifically includes the following processes:

[0074] The mixture was cooled to -78°C, and THF was added to the reaction flask. Then, raw material B-1 (1.2 eq, CAS No.: 108313-42-4) was added and dissolved in it. Nitrogen gas was replaced three times, and the mixture was stirred for 30 min. Then, n-butyllithium (1.5 eq) was slowly added to the reaction flask, and the reaction was allowed to proceed for 2 h. Raw material A-1 (1.0 eq, CAS No.: 4269-14-1) was dissolved in tetrahydrofuran, and the solution of raw material A-1 was slowly added dropwise to the reaction flask. The mixture was stirred until homogeneous, and the refrigeration was stopped. The mixture was then heated to room temperature and the reaction was allowed to continue for 12 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the mixture was washed three times with water, and the organic phase was retained. The aqueous phase was then extracted with dichloromethane. The organic phases were combined and concentrated. The intermediate 1-1 (yield: 64.9%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:2).

[0075] Step 2 specifically includes the following processes:

[0076] Dichloromethane was added to the reaction flask, followed by intermediate 1 (1.0 eq) dissolved therein. Triethylsilane (1.5 eq) was added under stirring at -10°C. After stirring for 30 min, methanesulfonic acid (3.0 eq) was added, and stirring was continued for 15 min. The mixture was then transferred to room temperature and reacted for 2 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, water was added to the reaction solution and stirred. The mixture was extracted and separated, retaining the organic phase. The aqueous phase was then extracted with dichloromethane. The organic phases were combined and concentrated. The intermediate 2-1 was purified by column chromatography using petroleum ether (yield: 72.7%).

[0077] Step 3 specifically includes the following processes:

[0078] THF was added to the reaction flask, followed by intermediate 2 (1.0 eq) dissolved in it. The mixture was stirred at room temperature until dissolved. Then, t-BuOK (5.0 eq) was slowly added to the reaction flask and stirred for 1 h. Then, iodomethane (5.0 eq) was slowly added dropwise. The mixture was heated to 80 °C and reacted for 12 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the temperature was lowered slightly, and the mixture was filtered with diatomaceous earth to remove salts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Intermediate 3-1 (yield: 66.4%) was obtained by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:5).

[0079] Step 4 specifically includes the following processes:

[0080] Intermediate 3-1 (1.0 eq), pinacol diborate (1.5 eq), and potassium acetate (3.0 eq) were added to a reaction flask, followed by 1,4-dioxane. Nitrogen gas was purged, and tris(dibenzylacetone)dipalladium (0.03 eq) and X-Phos (0.2 eq) were added under nitrogen protection. The mixture was then heated to 120 °C and refluxed for 14 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the temperature was slightly lowered, and the mixture was filtered with diatomaceous earth to remove salts and catalysts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Intermediate 4-1 (yield: 77.6%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V = 1:4).

[0081] Step 5 specifically includes the following processes:

[0082] Intermediate 4-1 (1.0 eq) and starting material D-1 (1.2 eq, CAS No.: 1360145-45-4) were added to a reaction flask, followed by a mixed solution of toluene, ethanol and water (V:V:V = 3:1:1). Nitrogen gas was introduced, and tetrakis(triphenylphosphine)palladium (0.01 eq) and potassium carbonate (2.0 eq) were added under nitrogen protection. The mixture was then heated to 95 °C and refluxed for 7 h. The mixture was filtered with diatomaceous earth to remove salt and catalyst. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Intermediate 5-1 (yield: 82.4%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V = 1:6).

[0083] Step 6 specifically includes the following processes:

[0084] Intermediate 5-1 (1.0 eq), pinacol diborate (1.5 eq), and potassium acetate (3.0 eq) were added to a reaction flask, followed by 1,4-dioxane. Nitrogen gas was purged, and tris(dibenzylacetone)dipalladium (0.03 eq) and X-Phos (0.2 eq) were added under nitrogen protection. The mixture was then heated to 120 °C and refluxed for 16 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the temperature was slightly lowered, and the mixture was filtered with diatomaceous earth to remove salts and catalysts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Intermediate 6-1 (yield: 77.8%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V = 1:4).

[0085] Step 7 specifically includes the following processes:

[0086] Intermediate 6-1 (1.0 eq) and starting material E-1 (1.0 eq, CAS No.: 3842-55-5) were added to a reaction flask, followed by a mixed solution of toluene, ethanol and water (V:V:V = 3:1:1). Nitrogen gas was introduced, and tetrakis(triphenylphosphine)palladium (0.04 eq) and potassium carbonate (4.0 eq) were added under nitrogen protection. The mixture was then heated to 95 °C and refluxed for 19 h. The mixture was filtered with diatomaceous earth to remove salts and catalysts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Compound 1 was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V = 1:5) to obtain compound 1 (yield: 85.3%).

[0087] The obtained compound 1 was analyzed, and the results are as follows:

[0088] HPLC purity: >99.7%.

[0089] Mass spectrometry test: Waters XEVO TQD mass spectrometer with ESI source.

[0090] Test value MS(ESI, m / Z): [M+H] + =730.39.

[0091] Elemental analysis:

[0092] The test values ​​were: C, 86.94; H, 4.93; N, 5.90; O, 2.31.

[0093] Nuclear magnetic resonance hydrogen spectrum: as shown Figure 1 As shown in (Compound 1).

[0094] Example 2

[0095]

[0096] Raw material A-217 corresponds to intermediate 3 in the general formula, which is existing technology; steps 1-3 in the general formula are omitted.

[0097] Step 1 specifically includes the following processes:

[0098] In a reaction flask, raw material A-217 (1.0 eq, CAS No.: 2606032-37-3), pinacol diborate (1.5 eq), and potassium acetate (3.0 eq) were added, followed by 1,4-dioxane. Nitrogen gas was introduced, and under nitrogen protection, tris(dibenzylacetone)dipalladium (0.03 eq) and X-Phos (0.2 eq) were added. The mixture was then heated to 120 °C and refluxed for 13 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the temperature was slightly lowered, and the mixture was filtered with diatomaceous earth to remove salts and catalysts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Intermediate 1-217 (yield: 78.0%) was obtained by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:4).

[0099] Step 2 specifically includes the following processes:

[0100] Intermediate 1-217 (1.0 eq) and starting material B-217 (1.2 eq, CAS No.: 2173554-83-9) were added to a reaction flask, followed by a mixed solution of toluene, ethanol and water (V:V:V = 3:1:1). Nitrogen gas was introduced, and tetrakis(triphenylphosphine)palladium (0.01 eq) and potassium carbonate (2.0 eq) were added under nitrogen protection. The mixture was then heated to 95 °C and refluxed for 6 h. The mixture was filtered with diatomaceous earth to remove salt and catalyst. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Intermediate 2-217 (yield: 82.5%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V = 1:6).

[0101] Step 3 specifically includes the following processes:

[0102] Intermediate 2-217 (1.0 eq), pinacol diborate (1.5 eq), and potassium acetate (3.0 eq) were added to a reaction flask, followed by 1,4-dioxane. Nitrogen gas was purged, and tris(dibenzylacetone)dipalladium (0.03 eq) and X-Phos (0.2 eq) were added under nitrogen protection. The mixture was then heated to 120 °C and refluxed for 15 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the temperature was slightly lowered, and the mixture was filtered with diatomaceous earth to remove salts and catalysts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Intermediate 3-217 (yield: 78.3%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:4).

[0103] Step 4 specifically includes the following processes:

[0104] Intermediate 3-217 (1.0 eq) and starting material C-217 (1.0 eq, CAS No.: 3842-55-5) were added to a reaction flask, followed by a mixed solution of toluene, ethanol and water (V:V:V = 3:1:1). Nitrogen gas was introduced, and tetrakis(triphenylphosphine)palladium (0.04 eq) and potassium carbonate (4.0 eq) were added under nitrogen protection. The mixture was then heated to 95 °C and refluxed for 18 h. The mixture was filtered with diatomaceous earth to remove salts and catalysts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Compound 217 (yield: 85.6%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V = 1:4).

[0105] The obtained compound 217 was analyzed, and the results are as follows:

[0106] HPLC purity: >99.8%.

[0107] Mass spectrometry test: Waters XEVO TQD mass spectrometer with ESI source.

[0108] Test value MS(ESI, m / Z): [M+H] + =654.35.

[0109] Elemental analysis:

[0110] The test values ​​were: C, 86.06; H, 4.89; N, 6.56; O, 2.56.

[0111] Nuclear magnetic resonance hydrogen spectrum: as shown Figure 2 As shown in (compound 217).

[0112] Example 3

[0113]

[0114] Intermediate A-637 corresponds to raw material A-637 in the general formula, which is not a prior art and needs to be synthesized first, as shown in step 1 below:

[0115] Step 1 specifically includes the following processes:

[0116] In a reaction flask, raw material a (1.0 eq, CAS No.: 4269-17-4) and raw material b (1.0 eq, CAS No.: 126747-14-6) were added, followed by a mixed solution of toluene, ethanol, and water (V:V:V = 3:1:1). Nitrogen gas was introduced, and under nitrogen protection, tetrakis(triphenylphosphine)palladium (0.01 eq) and potassium carbonate (2.0 eq) were added. The mixture was then heated to 95 °C and refluxed for 15 h. The mixture was filtered with diatomaceous earth to remove salts and catalysts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Intermediate A-637 (yield: 81.9%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V = 1:4).

[0117] Step 2 specifically includes the following processes:

[0118] The mixture was cooled to -78°C, and THF was added to the reaction flask. Then, raw material B-637 (1.2 eq, CAS No.: 108313-42-4) was dissolved in the solution. Nitrogen gas was replaced three times, and the mixture was stirred for 30 min. Then, n-butyllithium (1.5 eq) was slowly added to the reaction flask, and the reaction was allowed to proceed for 2 h. Intermediate A-637 (1.0 eq, CAS No.: 952573-40-9) was dissolved in tetrahydrofuran, and the solution of intermediate A was slowly added dropwise to the reaction flask. The mixture was stirred until homogeneous, and the refrigeration was stopped. The mixture was then heated to room temperature and the reaction continued for 14 h. The reaction was detected using thin-layer chromatography. After the reaction was complete, the mixture was washed three times with water, and the organic phase was retained. The aqueous phase was then extracted with dichloromethane. The organic phases were combined and concentrated. Intermediate 1-637 (yield: 64.0%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V = 1:2).

[0119] Step 3 specifically includes the following processes:

[0120] Dichloromethane was added to the reaction flask, followed by intermediate 1-637 (1.0 eq) dissolved therein. Triethylsilane (1.5 eq) was added under stirring at -10°C, and after stirring for 30 min, methanesulfonic acid (3.0 eq) was added. After stirring for another 15 min, the mixture was transferred to room temperature and reacted for 2 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, water was added to the reaction solution and stirred. The mixture was extracted and separated, retaining the organic phase. The aqueous phase was then extracted with dichloromethane. The organic phases were combined and concentrated. The intermediate 2-637 was purified by column chromatography using petroleum ether (yield: 72.3%).

[0121] Step 4 specifically includes the following processes:

[0122] THF was added to the reaction flask, followed by intermediate 2-637 (1.0 eq) dissolved in it. The mixture was stirred at room temperature until dissolved. Then, t-BuOK (5.0 eq) was slowly added to the reaction flask and stirred for 1 h. Then, iodomethane (5.0 eq) was slowly added dropwise, and the mixture was heated to 80 °C and reacted for 13 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the temperature was lowered slightly, and the mixture was filtered with diatomaceous earth to remove salts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Intermediate 3-637 (yield: 66.1%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:5).

[0123] Step 5 specifically includes the following processes:

[0124] Intermediate 3-637 (1.0 eq), pinacol diborate (1.5 eq), and potassium acetate (3.0 eq) were added to a reaction flask, followed by 1,4-dioxane. Nitrogen gas was purged, and tris(dibenzylacetone)dipalladium (0.03 eq) and X-Phos (0.2 eq) were added under nitrogen protection. The mixture was then heated to 120 °C and refluxed for 15 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the temperature was slightly lowered, and the mixture was filtered with diatomaceous earth to remove salts and catalysts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Intermediate 4-637 (yield: 77.4%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V = 1:4).

[0125] Step 6 specifically includes the following processes:

[0126] Intermediate 4-637 (1.0 eq) and starting material D-637 (1.2 eq, CAS No.: 2087889-86-7) were added to a reaction flask, followed by a mixed solution of toluene, ethanol and water (V:V:V = 3:1:1). Nitrogen gas was purged, and tetrakis(triphenylphosphine)palladium (0.01 eq) and potassium carbonate (2.0 eq) were added under nitrogen protection. The mixture was then heated to 95 °C and refluxed for 8 h. The mixture was filtered with diatomaceous earth to remove salts and catalysts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Intermediate 5-637 (yield: 82.2%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V = 1:6).

[0127] Step 7 specifically includes the following processes:

[0128] Intermediate 5-637 (1.0 eq), pinacol diborate (1.5 eq), and potassium acetate (3.0 eq) were added to a reaction flask, followed by 1,4-dioxane. Nitrogen gas was purged, and tris(dibenzylacetone)dipalladium (0.03 eq) and X-Phos (0.2 eq) were added under nitrogen protection. The mixture was then heated to 120 °C and refluxed for 17 h. The reaction was detected by thin-layer chromatography. After the reaction was completed, the temperature was slightly lowered, and the mixture was filtered with diatomaceous earth to remove salts and catalysts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Intermediate 6-637 (yield: 77.5%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:4).

[0129] Step 8 specifically includes the following processes:

[0130] Intermediate 6-637 (1.0 eq) and starting material E-637 (1.0 eq, CAS No.: 3842-55-5) were added to a reaction flask, followed by a mixed solution of toluene, ethanol and water (V:V:V = 3:1:1). Nitrogen gas was introduced, and tetrakis(triphenylphosphine)palladium (0.04 eq) and potassium carbonate (4.0 eq) were added under nitrogen protection. The mixture was then heated to 95 °C and refluxed for 20 h. The mixture was filtered with diatomaceous earth to remove salts and catalysts. Water and dichloromethane were added to the filtrate for separation and extraction. The organic phase was retained and concentrated. Compound 637 (yield: 84.8%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V = 1:5).

[0131] The obtained compound 637 was analyzed, and the results are as follows:

[0132] HPLC purity: >99.6%.

[0133] Mass spectrometry test: Waters XEVO TQD mass spectrometer with ESI source.

[0134] Test value MS(ESI, m / Z): [M+H] + =755.36.

[0135] Elemental analysis:

[0136] The test values ​​were: C, 85.65; H, 4.66; N, 7.56; O, 2.25.

[0137] Nuclear magnetic resonance hydrogen spectrum: as shown Figure 3 As shown in (Compound 637).

[0138] In addition, it should be noted that other compounds of the present invention can be obtained by referring to the preparation methods of the examples listed above, so they will not be listed one by one here.

[0139] Device Example 1: Fabrication of Organic Electroluminescent Devices

[0140] The structure of the fabricated OLED device is: ITO anode / HIL / HTL / Prime / EML / HBL / ETL / EIL / cathode / light extraction layer.

[0141] a. ITO anode: The ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 1500 angstroms was cleaned three times in distilled water and ultrasonically washed for 30 minutes. Then it was cleaned three times in distilled water and ultrasonically washed for 10 minutes. After washing, it was ultrasonically washed sequentially with methanol, acetone and isopropanol (5 minutes each time). After drying, it was transferred to a plasma cleaner for 5 minutes and then sent to a vapor deposition machine. Using this substrate as the anode, other functional layers were sequentially vapor deposited on it.

[0142] b. HIL (Hole Injection Layer): Hole injection layer materials HT and P-dopant are vacuum-deposited at a deposition rate of 1 Å / s. The chemical formulas are shown below. The deposition rate ratio of HT to P-dopant is 97:3, and the thickness is 10 nm.

[0143] c. HTL (Hole Transport Layer): A 130nm HT layer is vacuum-deposited on top of the hole injection layer at a deposition rate of 1.5 Å / s as the hole transport layer.

[0144] d. Prime (light-emitting auxiliary layer): A 5nm Prime is vacuum-deposited on the hole transport layer at a deposition rate of 0.5 Å / s as a light-emitting auxiliary layer.

[0145] e. EML (Emitting Layer): A host material and a dopant material with a thickness of 30 nm are vacuum-deposited on the emitting auxiliary layer at a deposition rate of 1 Å / s. The chemical formulas of the host and the dopant are shown below, and the deposition rate ratio of the host to the dopant is 97:3.

[0146] f. HBL (hole blocking layer): Compound 1 with a thickness of 5 nm was vacuum-deposited on the light-emitting layer at a deposition rate of 0.5 Å / s as a hole blocking layer.

[0147] g. ETL (Electron Transport Layer): ET and Liq with a thickness of 30 nm are vacuum-deposited on the hole blocking layer at a deposition rate of 1 Å / s, with the deposition rate ratio of ET to Liq being 50:50.

[0148] h. EIL (Electron Injection Layer): A Yb film with a thickness of 1 nm is vacuum-deposited on the electron transport layer at a deposition rate of 0.5 Å / s to form the electron injection layer.

[0149] i. Cathode: Magnesium and silver with a thickness of 13 nm are vacuum-deposited on the electron injection layer at a deposition rate of 1 Å / s, with a deposition rate ratio of 1:9 for magnesium and silver, to obtain the cathode.

[0150] j. Optical extraction layer: A CPL with a thickness of 70 nm is vacuum-deposited on the cathode at a deposition rate of 1 Å / s as the optical extraction layer.

[0151] K. Encapsulate the vapor-deposited substrate: First, use a coating equipment to coat the cleaned cover plate with UV adhesive. Then, move the coated cover plate to the lamination section, place the vapor-deposited substrate on the top of the cover plate, and finally, laminate the substrate and cover plate together under the action of the lamination equipment, while simultaneously curing the UV adhesive by light.

[0152] The required material structure is shown below:

[0153] .

[0154] Device Example 2-142

[0155] Referring to the method provided in Device Example 1 above, the corresponding compounds in Table 1 below were selected to replace compound 1, and hole blocking layers were deposited to prepare the corresponding organic electroluminescent devices, which are respectively referred to as Device Examples 2-142.

[0156] Device Comparison Examples 1-15

[0157] Devices 1-15 were prepared according to the method provided in Device Example 1 above, except that the hole blocking layer (compound 1) in Device Example 1 was replaced with the existing comparative compound ao, wherein the structural formula of compound ao is as follows:

[0158] .

[0159] The driving voltage, BI value, and lifetime of the organic electroluminescent devices obtained in Examples 1-142 and Comparative Examples 1-15 were characterized at a brightness of 1000 nits. The test results are shown in Table 1 below.

[0160] Table 1. Device Test Results

[0161]

[0162]

[0163]

[0164]

[0165] Device Example 143: Fabrication of Organic Electroluminescent Devices

[0166] The structure of the fabricated OLED device is: ITO anode / HIL / HTL / Prime / EML / HBL / ETL / EIL / cathode / light extraction layer.

[0167] a. ITO anode: The ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 1500 angstroms was cleaned three times in distilled water and ultrasonically washed for 30 minutes. Then it was cleaned three times in distilled water and ultrasonically washed for 10 minutes. After washing, it was ultrasonically washed sequentially with methanol, acetone and isopropanol (5 minutes each time). After drying, it was transferred to a plasma cleaner for 5 minutes and then sent to a vapor deposition machine. Using this substrate as the anode, other functional layers were sequentially vapor deposited on it.

[0168] b. HIL (Hole Injection Layer): Hole injection layer materials HT and P-dopant are vacuum-deposited at a deposition rate of 1 Å / s. The chemical formulas are shown below. The deposition rate ratio of HT to P-dopant is 97:3, and the thickness is 10 nm.

[0169] c. HTL (Hole Transport Layer): A 130nm HT layer is vacuum-deposited on top of the hole injection layer at a deposition rate of 1.5 Å / s as the hole transport layer.

[0170] d. Prime (light-emitting auxiliary layer): A 5nm Prime is vacuum-deposited on the hole transport layer at a deposition rate of 0.5 Å / s as a light-emitting auxiliary layer.

[0171] e. EML (Emitting Layer): A host material and a dopant material with a thickness of 30 nm are vacuum-deposited on the emitting auxiliary layer at a deposition rate of 1 Å / s. The chemical formulas of the host and the dopant are shown below, and the deposition rate ratio of the host to the dopant is 97:3.

[0172] f. HBL (hole blocking layer): A 5nm thick HB layer is vacuum-deposited on the light-emitting layer at a deposition rate of 0.5 Å / s as a hole blocking layer.

[0173] g. ETL (Electron Transport Layer): Compound 513 and Liq with a thickness of 30 nm were vacuum-deposited on the hole blocking layer at a deposition rate of 1 Å / s, wherein the deposition rate ratio of compound 637 and Liq was 50:50.

[0174] h. EIL (Electron Injection Layer): A Yb film with a thickness of 1 nm is vacuum-deposited on the electron transport layer at a deposition rate of 0.5 Å / s to form the electron injection layer.

[0175] i. Cathode: Magnesium and silver with a thickness of 13 nm are vacuum-deposited on the electron injection layer at a deposition rate of 1 Å / s, with a deposition rate ratio of 1:9 for magnesium and silver, to obtain the cathode.

[0176] j. Optical extraction layer: A CPL with a thickness of 70 nm is vacuum-deposited on the cathode at a deposition rate of 1 Å / s as the optical extraction layer.

[0177] K. Encapsulate the vapor-deposited substrate: First, use a coating equipment to coat the cleaned cover plate with UV adhesive. Then, move the coated cover plate to the lamination section, place the vapor-deposited substrate on the top of the cover plate, and finally, laminate the substrate and cover plate together under the action of the lamination equipment, while simultaneously curing the UV adhesive by light.

[0178] The required material structure is shown below:

[0179] .

[0180] Device Examples 144-221

[0181] Referring to the method provided in Device Example 143 above, the corresponding compounds in Table 2 below were selected to replace compound 513, and the electron transport layer was deposited to prepare the corresponding organic electroluminescent devices, which are respectively referred to as Device Examples 144-221.

[0182] Device Comparison Examples 16-20

[0183] Devices 16-20 were fabricated according to the method provided in Device Example 143 above, except that the electron transport layer (compound 513) in Device Example 143 was replaced with the existing comparative compound pt, wherein the structural formula of compound pt is as follows:

[0184] .

[0185] The driving voltage, BI value, and lifetime of the organic electroluminescent devices obtained in Device Examples 143-221 and Device Comparative Examples 16-20 were characterized at a brightness of 1000 nits. The test results are shown in Table 2 below.

[0186] Table 2 Device Test Results

[0187]

[0188]

[0189]

[0190] Those skilled in the art will know that in blue top-emitting devices, luminous efficiency is greatly affected by chromaticity. Therefore, taking into account the influence of chromaticity on efficiency, the ratio of luminous efficiency to CIEy is defined as the BI value, i.e., BI = (cd / A) / CIEy. In the test, the CIEy value is adjusted to be between 0.043 and 0.045.

[0191] As can be seen from Tables 1 and 2, compared with the light-emitting devices prepared using the comparative compounds, the organic electroluminescent devices prepared using the electron transport function provided by the present invention exhibit superior device performance, with lower driving voltage, higher luminous efficiency, and longer lifespan.

[0192] Comparative compounds a, b, c, and d are parallel comparative examples to compounds 242, 162, 217, and 465 of this invention. The difference lies in the structure: the compounds of this invention have a dibenzofuran group linked to a 9-alkyl-9-phenylfluorene, while the comparative compounds a, b, c, and d have a 9,9-diphenyl-benzofluorene or spirodifluorene linked to it. This increases the molecular weight, leading to a higher vapor deposition temperature. Excessively high vapor deposition temperatures increase the tendency for material thermal decomposition during device fabrication, affecting the device's lifespan.

[0193] The comparative compounds e, f, g, h, i and the compounds 177, 445, 353, 456, 161 of this invention are parallel comparative examples. The difference is that in the comparative compounds, the triazine group and the 9-alkyl-9-phenylfluorene group (phenyl group attached to the 9th position of fluorene) are directly connected or connected through phenylene. Direct connection may lead to an excessively high hole injection barrier, while the energy level regulation ability of phenyl is relatively weak, and direct connection or phenyl bridge will make the molecule relatively flexible, which may lead to a decrease in thermal stability and a shortened lifespan of the device. The compound of this invention has a structure in which a dibenzofuran group serves as a bridging group between a triazine group and a 9-alkyl-9-phenylfluorene group (a phenyl group attached to the 9-position of fluorene). This dibenzofuran group possesses moderate electron-donating capability, which can buffer the direct electron-withdrawing effect of the triazine group on the fluorene group, thereby modulating the HOMO / LUMO energy levels and improving carrier injection balance. Furthermore, as a bridge between the donor and acceptor, dibenzofuran can enhance intramolecular charge transfer effects. Simultaneously, through spatial conjugation or π-expansion, it may narrow the singlet-tritium band gap, improving exciton utilization and effectively increasing the luminescence efficiency of the device. In addition, dibenzofuran has a rigid planar structure, which can increase the glass transition temperature (Tg) of the molecule, reduce the tendency for crystallization in the thin film state, enhance morphological stability, and contribute to improving the lifespan of the device.

[0194] Comparative compounds j, k, l, m, n, and o are parallel comparative examples to compounds 162, 69, 133, 386, 409, and 320 of this invention. The difference lies in the structure: in the comparative compounds, the triazine group is linked to a dibenzofuran group, which is then linked to a phenyl group, while in the compounds of this invention, the triazine group is linked to a dibenzofuran group, which is then linked to a 9-alkyl-9-phenylfluorene group (a phenyl group attached to the 9-position of the fluorene group). This introduces significant three-dimensional steric hindrance into the molecule. In solid-state films, this structure effectively prevents π-π stacking between adjacent luminescent molecules, suppressing concentration quenching and exciton annihilation caused by excessive molecular proximity, directly improving the luminescence efficiency of the material in the solid state. Furthermore, the large, rigid fluorene structure and the presence of the alkyl chain significantly increase the glass transition temperature of the molecule. During device fabrication and operation, the material is less prone to crystallization, forming a uniform and stable amorphous film, which effectively extends the device's lifespan.

[0195] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A material with electron transport function, characterized in that, The material with electron transport function has the general structural formula shown in chemical formulas IA~IB: ； in, R is an unsubstituted or deuterated methyl, an unsubstituted or deuterated ethyl, an unsubstituted or deuterated propyl, an unsubstituted or deuterated isopropyl, or an unsubstituted or deuterated tert-butyl. Ar1 and Ar2 are independently selected from hydrogen, deuterium, and the following structures: ； Ar3 and Ar4 are each independently selected from the following structures: R1, R2, and R3 are independently selected from hydrogen and deuterium, respectively; n1 and n3 are independently selected from 0, 1, 2, 3, and 4; n2 is independently selected from 0, 1, 2, and 3; In the chemical formulas IA and IB, any one hydrogen atom can be independently replaced by deuterium; Indicates the linking site of a functional group.

2. A material with electron transport function, characterized in that, The material with electron transport function has the general structural formula shown in chemical formulas IA~IB: ； in, R is an unsubstituted or deuterated methyl, an unsubstituted or deuterated ethyl, an unsubstituted or deuterated propyl, an unsubstituted or deuterated isopropyl, or an unsubstituted or deuterated tert-butyl. Ar1 and Ar2 are independently selected from hydrogen, deuterium, and the following structures: ； Ar3 and Ar4 are each independently selected from the following structures: R1, R2, and R3 are independently selected from hydrogen and deuterium, respectively; n1 and n3 are independently selected from 0, 1, 2, 3, and 4; n2 is independently selected from 0, 1, 2, and 3; In the chemical formulas IA and IB, any one hydrogen atom can be independently replaced by deuterium; Indicates the linking site of a functional group.

3. The material with electronic transmission function according to claim 1, characterized in that, The chemical formulas IA to IB have any one of the structures of compounds 1-512: 。 4. The material with electronic transmission function according to claim 2, characterized in that, The chemical formulas IA to IB have any one of the structures of compounds 513-736: 。 5. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes an anode, a cathode, and an organic material layer disposed between the anode and the cathode. The organic material layer contains a hole-blocking layer, and the hole-blocking layer is a material with electron transport function as described in any one of claims 1 and 3.

6. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes an anode, a cathode, and an organic material layer disposed between the anode and the cathode. The organic material layer contains an electron transport layer, which is a material with electron transport function as described in any one of claims 2 and 4.

7. The application of the organic electroluminescent device as described in claim 5 or 6 in an organic electroluminescent apparatus.

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