An organic compound and use thereof

Abstract

The application provides an organic compound and application thereof. The organic compound of the application can effectively improve the electron mobility of an electron transport material, improve the problem of electron-hole imbalance in an organic electroluminescent device, ensure a high triplet energy level of the material, a wide band gap, improve the light-emitting efficiency, improve the degree of matching of energy levels of layers of the device, reduce the driving voltage, and prolong the service life of the device.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of organic light-emitting materials, and relates to an organic compound and application thereof. BACKGROUND

[0002] With the rapid development of information technology, people have put forward new goals and requirements for the performance of information display systems, and high brightness, high resolution, wide viewing angle and low energy consumption have become research hotspots. Organic electroluminescence (OLED) display technology can meet the above needs of people, and has other advantages such as wide working temperature and flexible display. It has the following structure: anode, cathode and organic material layer between the two. In order to improve the efficiency and stability of the organic electroluminescence element, the organic material layer usually includes multiple layers with different materials, such as hole injection layer (HIL), hole transport layer (HTL), light-emitting layer, electron transport layer (ETL) and electron injection layer (EIL). In such an organic light-emitting element, when a voltage is applied between the anode and the cathode, holes from the anode and electrons from the cathode are injected into the organic material layer, and the generated excitons produce light with a specific wavelength when they migrate to the ground state.

[0003] The electron transport layer is responsible for regulating the injection speed and injection amount of electrons. In order to improve the injection and transport of electrons, high-mobility electron injection and transport materials need to be used. The electron transport material needs to have a high glass transition temperature (Tg), and widely used electron transport materials include Bphen, TPBi, BCP, BAlq, TAZ, etc. In some light-emitting devices, especially in blue light devices, the triplet energy level of the electron transport material needs to be higher than that of the light-emitting dye, so as to fully confine the excitons in the light-emitting layer.

[0004] At present, the structure of the electron transport type material usually contains electron-withdrawing groups such as pyridine, pyrimidine, oxadiazole, triazole, imidazole and other nitrogen-containing heterocycles with electron transport performance, but the electron mobility of general organic materials is low, while the hole mobility is relatively high, which causes the imbalance of electrons and holes inside the light-emitting device, thereby leading to problems such as low device efficiency, poor stability, short service life and the like.

[0005] Therefore, in the field, it is desirable to develop a material that can solve the problems of low device efficiency, poor stability, short service life and the like caused by low electron mobility. SUMMARY

[0006] In view of the deficiencies of the prior art, the purpose of the present application is to provide an organic compound and application thereof. The organic compound of the present application can be used as an electron transport material, and can solve the problems of low device efficiency, poor stability, short service life and the like caused by low electron mobility of existing electron transport materials.

[0007] To achieve the object of the present application, the present application adopts the following technical solutions:

[0008] In one aspect, the present application provides an organic compound having a structure shown in Formula I:

[0009]

[0010] wherein Ar1 and Ar2 independently represent the following groups:

[0011]

[0012] Z1-Z5 are selected from C, N, C-CN or C-Ar, and there are at least one N and at least one C-CN in Z1-Z5;

[0013] Ar is selected from substituted or unsubstituted C6-C 30 aryl, substituted or unsubstituted C5-C 30 heteroaryl, and * represents the connecting position of the group;

[0014] L is a connecting bond or substituted or unsubstituted C4-C30 aryl or substituted or unsubstituted C4-C30 heteroaryl;

[0015] R1 and R2 are independently selected from cyano, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C1-C30 aliphatic alkyl, substituted or unsubstituted C5-C30 aryl or substituted or unsubstituted C5-C30 heteroaryl;

[0016] X and Y independently represent a connecting bond, O, S, C-R5R6, N-R7, R5-R7 are independently selected from substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 3-30-membered heteroaryl;

[0017] one of m and n is 0, and the other is 1;

[0018] The organic compound of the present application can effectively improve the electron mobility of the electron transport material, improve the problem of electron-hole imbalance in the organic electroluminescent device, while ensuring the high triplet energy level (ET) of the material, the wide band gap, improving the light-emitting efficiency, and improving the degree of energy level matching of each layer of the device, reducing the driving voltage, prolonging the service life of the device, and having excellent device performance compared with the prior art.

[0019] In the present application, the heteroatom contained in the heteroaryl is selected from oxygen, nitrogen or sulfur.

[0020] In the present application, the number range of carbon atoms in the group is limited, which means that the number of carbon atoms contained in the group is any integer within the limited range, for example, C6-C30 represents any integer from 6 to 30, for example, 6, 8, 10, 12, 15, 18, 20, 23, 25, 28, or 30.

[0021] Preferably, at least one of Z1 to Z5 is N, at least one is C-CN, at least one is C-Ar, and the rest are C.

[0022] Preferably, Ar is one of the following groups:

[0023]

[0024]

[0025] * indicates the position of the group connection.

[0026] Preferably, L is selected from a single bond, phenyl, biphenyl, naphthyl, pyridyl, or cyano-substituted pyridyl. Preferably, Ar1 and Ar2 are independently selected from any one of the following groups:

[0027]

[0028]

[0029] * indicates the position of the group connection.

[0030] Preferably, R1 and R2 are independently selected from any one of the following groups:

[0031] * indicates the position of the group connection.

[0032] Preferably, the organic compound has a structure represented by any one of the following general formulas:

[0033]

[0034] wherein R5 to R7 are independently selected from substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted 3- to 30-membered heteroaryl, Ar1, Ar2, R1, R2, m, and n are the same as defined in formula I.

[0035] It is worth noting that in the present application, "*" indicates the connection point. The term "substituted" means substituted with one, two, or more substituents selected from one or more of hydrogen, deuterium, cyano, halogen, nitro, hydroxyl, phosphato, borane, silicon, C1-C8 alkyl, C2-C15 alkenyl, C2-C10 alkynyl, C6-C20 aryl, C3-C10 heteroaryl, C1-C10 alkoxy, and C6-C20 arylamino.

[0036] Preferably, the organic compound is any one of the following compounds:

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045] In the present application, the method for preparing the organic compound is as follows: when m = 1,

[0046]

[0047] when n = 1:

[0048]

[0049] Hal1-Hal3 in the above formula are the same as or different from each other and are independently selected from chlorine, bromine or iodine.

[0050] First step: dissolve raw material 1 in DMF, add raw material 2, protect with nitrogen, add cuprous iodide, potassium phosphate, and gradually raise the temperature to 150-160°C, then gradually raise the room temperature and react overnight. After confirming that the reaction is complete by TLC, lower the temperature to room temperature. Post-treatment process: add deionized water, precipitate is separated out, filter, and obtain white solid. The compound shown in intermediate 1 is obtained.

[0051] Second step: dissolve intermediate 1 in anhydrous tetrahydrofuran, protect with nitrogen, and stir at -78°C for 30 minutes. Inject n-butyllithium (2.5 mol / L) and react for 2-4 hours, then add raw material 3 and react at low temperature for 4-6 hours, and place the reaction bottle at room temperature and react overnight. Post-treatment process: add deionized water and stir for 10-20 minutes, separate the liquid, extract the water layer with ethyl acetate once, combine the organic layers, dry with anhydrous magnesium sulfate. Spin dry to obtain yellow oil, purify by column, wash out the target product with a mixed solvent of dichloromethane and petroleum ether, spin dry to obtain colorless oil intermediate 2.

[0052] Third step: Dissolve intermediate 2 in dichloromethane, stir at 0°C for 30-40 minutes. Add methanesulfonic acid to the reaction solution under nitrogen protection, react for 1-2 hours. Then warm the reaction to room temperature, react for 4-6 hours, and end the reaction. Post-processing: solid precipitates, filter, obtain white solid, wash with petroleum ether, and dry to obtain intermediate 3.

[0053] Fourth step: Add intermediate 3 and raw material 4 to a reaction bottle, then add palladium catalyst, phosphine ligand, and cesium carbonate, and finally add to a mixed solution of toluene, ethanol, and deionized water, protect under nitrogen, and react at 90-100°C for 22-24 hours. Post-processing: cool, static separation, wash the organic layer once with water, purify the product by column, flush the target product out with a mixed solution of dichloromethane and petroleum ether, collect the product point, and spin dry to obtain the target product of general formula 1.

[0054] When X and Y are both linking groups, the reaction general formula is as follows:

[0055] When m=1 and n=1, the reaction general formula is consistent

[0056]

[0057] Note: Hal1-Hal3 in the above formula are the same or different from each other, and are independently selected from chlorine, bromine, or iodine

[0058] First step: Add raw material 1 and raw material 2 to a reaction bottle, then add palladium catalyst, potassium carbonate, and finally add to a mixed solution of toluene, ethanol, and deionized water, protect under nitrogen, and react at 90-100°C for 10-12 hours. After determining that the reaction is complete by TLC method, cool to room temperature. Post-processing: add deionized water, precipitate is separated out, filter, and obtain white solid. The compound shown in intermediate 1 is obtained.

[0059] Second step: Dissolve intermediate 1 in anhydrous tetrahydrofuran, stir at -78°C for 30 minutes under nitrogen protection. Inject n-butyllithium (2.5 mol / L) and react for 2-4 hours, then add raw material 3 and react at low temperature for 4-6 hours, and place the reaction bottle at room temperature to react overnight. Post-processing: add deionized water and stir for 10-20 minutes, separate, extract the water layer with ethyl acetate once, combine the organic layers, and dry with anhydrous magnesium sulfate. Spin dry to obtain yellow oil, purify by column, flush the target product out with a mixed solvent of dichloromethane and petroleum ether, spin dry to obtain colorless oil intermediate 2.

[0060] Third step: Dissolve intermediate 2 in dichloromethane, stir at 0°C for 30-40 minutes. Add methanesulfonic acid to the reaction solution under nitrogen protection, react for 1-2 hours. Then warm the reaction to room temperature, react for 4-6 hours, and end the reaction. Post-processing: solid precipitates, filter, obtain white solid, wash with petroleum ether, and dry to obtain intermediate 3.

[0061] Fourth step: intermediate 3 and raw material 4 are added to the reaction bottle, then palladium catalyst, phosphine ligand and cesium carbonate are added, and finally added to the mixed solution of toluene, ethanol and deionized water, protected by nitrogen, reacted at 90-100℃ for 22-24 hours. Post-processing process: cooling, static separation, washing the organic layer once, purifying the product through a column, washing out the target product with a mixed solution of dichloromethane and petroleum ether, collecting the product point, and drying to obtain the target product general formula 1.

[0062] A series of palladium-catalyzed coupling reactions are carried out in the present application, on the one hand, taking advantage of the difference in halogen activity I>Br>>Cl, and on the other hand, by controlling the reaction site by controlling the reaction conditions, and purifying the reaction by column chromatography or silica gel funnel to remove by-products to obtain the target compound. The commonly known knowledge is as follows: Transition Metal Organic Chemistry (6th edition), Robert H. Crabtree, Publisher: East China University of Technology Press, Publication Time: 2017-09-00, ISBN: 978-7-5628-5111-0, page 388. Organic Chemistry and Optoelectronic Material Experiment Course, Chen Runfeng, Publisher: Southeast University Press, Publication Time: 2019-11-00, ISBN: 9787564184230, page 174.

[0063] On the other hand, the present application provides an electron transport material, which comprises any one or a combination of at least two of the organic compounds described above.

[0064] On the other hand, the present application provides an organic electroluminescent device, which comprises a first electrode, a second electrode, and an organic thin film layer disposed between the first electrode and the second electrode, and the organic thin film layer comprises the organic compound described above.

[0065] Preferably, the organic thin film layer comprises an electron transport layer, and the electron transport layer comprises the organic compound described above.

[0066] In the present application, the electron transport material contains functional groups with strong electron-withdrawing ability (such as pyridine, pyrimidine, etc.), which can effectively improve the electron mobility of the electron transport material, and the specific functional groups containing polyazacyclic rings can further improve the electron mobility of the electron transport material, improve the problem of electron-hole imbalance inside the organic electroluminescent device, while ensuring the high triplet energy level (ET) of the material, wide band gap, further improve the light-emitting efficiency, and improve the degree of energy level matching between the layers of the device, reduce the driving voltage, prolong the service life of the device, and have excellent device performance compared with the prior art.

[0067] Preferably, the organic thin film layer further comprises any one of 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 injection layer, or a combination of at least two of the layers.

[0068] As for the compound represented by the above formula I, in the production of an organic light emitting element, an organic layer can be formed by a vacuum evaporation method or a solution coating method. The solution coating method includes, but is not limited to, spin coating, dip coating, blade coating, inkjet printing, screen printing, spray coating, and roll coating.

[0069] The light emitting device of the present application can be a top emission type, a bottom emission type, or a bidirectional emission type, depending on the materials used.

[0070] The device of the present application can be used in an organic light emitting device, an organic solar cell, electronic paper, an organic photoreceptor, or an organic thin film transistor.

[0071] As an anode material, a material having a large work function is preferable in order to smoothly inject holes into the organic layer. Specific examples of the anode material that can be used in the present application include metals such as vanadium, chromium, copper, zinc, and gold, or alloys thereof; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); combinations of a metal and an oxide such as ZnO:Al or SnO2:Sb; and electrically conductive polymers such as polypyrrole and polyaniline.

[0072] The hole injection layer is preferably a p-doped hole injection layer, which means a hole injection layer doped with a p-dopant. The p-dopant is a material that imparts p-type semiconductor properties. The p-type semiconductor properties mean the properties of injecting or transporting holes at the HOMO level, i.e., the properties of a material having a high hole conductivity.

[0073] The hole transport material is a material that receives holes from the anode or the hole injection layer and transports the holes to the light emitting layer, and has a high hole mobility. The hole transport material can be selected from arylamine derivatives, electrically conductive polymers, and block copolymers having both a conjugated portion and a non-conjugated portion.

[0074] A light emitting auxiliary layer (a multi-layer hole transport layer) is added between the hole transport layer and the light emitting layer. The light emitting auxiliary layer mainly functions as an auxiliary hole transport layer, and is sometimes referred to as a second hole transport layer. The light emitting auxiliary layer enables smooth movement of holes transferred from the anode to the light emitting layer, and can block electrons transferred from the cathode to confine the electrons within the light emitting layer, reduce the potential barrier between the hole transport layer and the light emitting layer, lower the driving voltage of the organic electroluminescent device, further increase the utilization efficiency of holes, and thus improve the light emitting efficiency and the lifetime of the device.

[0075] The light emitting substance of the light emitting layer is a substance capable of receiving holes and electrons from the hole transport layer and the electron transport layer, respectively, and causing them to combine to emit light in the visible light region, and is preferably a substance having high quantum efficiency for fluorescence or phosphorescence.

[0076] The light emitting layer can include a host material and a dopant material.

[0077] The mass ratio of the host material and the dopant material is (90-99.5):(0.5-10).

[0078] The host material is an aromatic condensed ring derivative or a heterocycle-containing compound, etc. Specifically, as the aromatic condensed ring derivative, there are anthracene derivatives, pyrene derivatives, naphthalene derivatives, pentacene derivatives, phenanthrene compounds, fluoranthene compounds, etc.; and as the heterocycle-containing compound, there are carbazole derivatives, diphenyl furan derivatives, pyrimidine derivatives, etc.

[0079] The dopant material of the present application includes fluorescent doping and phosphorescent doping, and can be selected from aromatic amine derivatives, styryl amine compounds, boron complexes, fluoranthene compounds, metal complexes, etc.

[0080] The electron transport layer can function to facilitate electron transport. The electron transport material is a material that is advantageous for receiving electrons from the cathode and transporting the electrons to the light emitting layer, and is preferably a material having high electron mobility. The electron transport layer can include at least one of an electron buffer layer, a hole blocking layer, an electron transport layer, and an electron injection layer, and preferably at least one of the electron transport layer and the electron injection layer. The electron transport layer material of the present application is a compound represented by Formula I.

[0081] The electron injection layer can function to facilitate electron injection, has the ability to transport electrons, and prevents excitons generated in the light emitting layer from migrating to the hole injection layer. The material of the electron injection layer includes oxazole, oxadiazole, triazole, imidazole, perylene tetracarboxylic acid, fluorenyl methane, anthracene ketone, and derivatives thereof, metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, ytterbium, etc. or alloys thereof, metal complexes, nitrogen-containing 5-membered ring derivatives, etc., but is not limited thereto.

[0082] The cathode is generally preferably a material having a small work function to allow smooth injection of electrons into the organic material layer, and the layer thickness thereof is preferably between 0.5 and 5 nm. The cathode material is generally preferably a material having a small work function to allow easy injection of electrons into the organic material layer. As specific examples of the cathode material, there are metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, etc. or alloys thereof: LiF / Al or LiO2 / Al, Mg / Ag, etc. multilayer structure materials, etc.

[0083] The OLED device has no special limitation on the materials of other layers except that the electron transport layer contains the compound of Formula I. The existing hole injection material, hole transport material, hole transport auxiliary material, dopant material, hole blocking layer material, electron transport layer material and electron injection material can be used.

[0084] In another aspect, the present application provides a display panel comprising the organic electroluminescent device as described above.

[0085] In another aspect, the present application provides an electronic device comprising the display panel as described above.

[0086] Compared with the prior art, the present application has the following beneficial effects:

[0087] The organic compound of the present application can effectively improve the electron mobility of the electron transport material, improve the problem of electron-hole imbalance in the organic electroluminescent device, ensure the high triplet energy level (ET) of the material, widen the band gap, improve the light-emitting efficiency, improve the degree of matching of the energy levels of the layers of the device, reduce the driving voltage, and prolong the service life of the device. BRIEF DESCRIPTION OF DRAWINGS

[0088] Figure 1 NMR spectrum of the intermediate 1 prepared in Example 1.

[0089] Figure 2 NMR spectrum of the compound ET-1 prepared in Example 1. DETAILED DESCRIPTION

[0090] The technical solutions of the present application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations of the present application.

[0091] Example 1

[0092]

[0093] First step: dissolve the raw material 1 (1.0 eq) in 500 mL of DMF, add the raw material 2 (1.0 eq), protect with nitrogen, add cuprous iodide (0.5 eq), potassium phosphate (3.0 eq), and gradually increase the temperature to 150°C. After the reaction is completed by TLC method, the temperature is lowered to room temperature. Post-treatment process: add deionized water, precipitate is separated out, filter, and obtain white solid. The compound shown in intermediate 1 is obtained (yield 60.5%).

[0094] Second step: Intermediate 1 (1.0 eq) was dissolved in 300 mL of anhydrous tetrahydrofuran, and stirred for 30 minutes under nitrogen protection at -78°C. n-Butyllithium (2.5 mol / L) (2.5 eq) was injected into the reaction solution, and the reaction was allowed to proceed for 2 hours. Then, raw material 3 (1.0 eq) was added, and the reaction was allowed to proceed for 4 hours at low temperature. The reaction bottle was allowed to stand at room temperature overnight. The post-treatment process was as follows: 70 mL of deionized water was added, and stirred for 10 minutes. The liquid was separated, and the water layer was extracted with ethyl acetate once. The organic layers were combined, and dried over anhydrous magnesium sulfate. The yellow oil obtained after rotary evaporation was purified by column chromatography, and the target product was eluted with dichloromethane: petroleum ether (V:V) = 1:2. The colorless oil obtained after rotary evaporation was intermediate 2 (yield 58.2%).

[0095] Third step: Intermediate 2 (1.0 eq) was dissolved in 300 mL of dichloromethane, and stirred for 30 minutes at 0°C. Methyl sulfonic acid (5.0 eq) was added to the reaction solution under nitrogen protection, and the reaction was allowed to proceed for 1 hour. Then, the reaction was allowed to proceed for 4 hours at room temperature, and the reaction was completed. The post-treatment process was as follows: solid was precipitated, and was filtered under suction to obtain white solid. The white solid was washed with petroleum ether, and dried to obtain intermediate 3 (yield 77.1%).

[0096] Fourth step: Intermediate 3 (1.0 eq) and raw material 4 (1.1 eq) were added to a reaction bottle, and then palladium catalyst (0.01 eq), phosphine ligand (0.05 eq), and cesium carbonate (2.0 eq) were added. Finally, 200 mL of toluene, 100 mL of ethanol, and 100 mL of deionized water were added, and the reaction was allowed to proceed for 24 hours at 90°C under nitrogen protection. The post-treatment process was as follows: the temperature was lowered, and the liquid was allowed to stand to separate. The organic layer was washed with water once. The product was purified by column chromatography, and the target product was eluted with dichloromethane: petroleum ether (V:V) = 1:1. The product was collected at the product point, and rotary evaporation was performed to obtain the target product ET-1 (yield 51.4%).

[0097] The obtained compound ET-1 was subjected to detection analysis, and the results were as follows:

[0098] HPLC purity: >99%.

[0099] Mass spectrometry calculation value: 602.69; mass spectrometry test value: 602.88;

[0100] Elemental analysis:

[0101] The calculation value was: C, 85.69; H, 4.35; N, 4.65; O, 5.31.

[0102] The test value was: C, 85.17; H, 4.73; N, 5.04; O, 5.47.

[0103] Figure 1 The nuclear magnetic resonance spectrum of intermediate 1 prepared in Example 1. Figure 2 The nuclear magnetic resonance spectrum of compound ET-1 prepared in Example 1.

[0104] Example 2

[0105]

[0106] First step: Put raw material 1 (1.0 eq) and raw material 2 (1.1 eq) into a reaction bottle, then add palladium catalyst (0.01 eq), potassium carbonate (2.0 eq), and finally add to a mixture of toluene, ethanol, and deionized water, protect with nitrogen, and react at 90-100°C for 10-12 hours. After determining that the reaction is complete by TLC method, cool to room temperature. Post-processing: add deionized water, precipitate is separated out, filter, and obtain white solid. The compound shown in intermediate 1 is obtained (yield 45.7%).

[0107] Second step: Dissolve intermediate 1 (1.0 eq) in 300 mL of anhydrous tetrahydrofuran, protect with nitrogen, and stir at -78°C for 30 minutes. Inject n-butyllithium (2.5 mol / L) (2.5 eq) and react for 2 hours, then add raw material 3 (1.0 eq) and react at low temperature for 4 hours. Place the reaction bottle at room temperature and react overnight. Post-processing: add 70 mL of deionized water and stir for 10 minutes, separate the layers, extract the water layer with ethyl acetate once, combine the organic layers, and dry with anhydrous magnesium sulfate. Spin dry to obtain yellow oil, purify by column chromatography, elute the target product with dichloromethane: petroleum ether (V:V) = 1:2, and spin dry to obtain colorless oil intermediate 2 (yield 53.8%).

[0108] Third step: Dissolve intermediate 2 (1.0 eq) in 300 mL of dichloromethane, and stir at 0°C for 30 minutes. Add methanesulfonic acid (5.0 eq) to the reaction solution under nitrogen protection and react for 1 h. Then warm the reaction to room temperature and react for 4 h until the reaction is complete. Post-processing: solid precipitates, filter, obtain white solid, wash with petroleum ether, and dry to obtain intermediate 3 (yield 75.2%).

[0109] Fourth step: Put intermediate 3 (1.0 eq) and raw material 4 (1.1 eq) into a reaction bottle, then add palladium catalyst (0.01 eq), phosphine ligand (0.05 eq), and cesium carbonate (2.0 eq), and finally add to 200 mL of toluene, 100 mL of ethanol, and 100 mL of deionized water, protect with nitrogen, and react at 90°C for 24 hours. Post-processing: cool, separate the layers, wash the organic layer with water once, purify the product by column chromatography, elute the target product with dichloromethane: petroleum ether (V:V) = 1:1, collect the product point, and spin dry to obtain the target product ET-18 (yield 49.6%).

[0110] The obtained compound ET-18 was detected and analyzed, and the results are as follows:

[0111] HPLC purity: >99%.

[0112] Mass calculated: 570.70; Mass found: 570.91;

[0113] Elemental analysis:

[0114] Calculated: C, 90.50; H, 4.59; N, 4.91.

[0115] Found: C, 89.97; H, 4.81; N, 5.24.

[0116] Example 3

[0117]

[0118] First step: Dissolve raw material 1 (1.0 eq) in 500 mL of DMF, add raw material 2 (1.0 eq), nitrogen protection, add cuprous iodide (0.5 eq), potassium phosphate (3.0 eq), and gradually increase the temperature to 150°C. After the reaction is complete, as determined by TLC, reduce the temperature to room temperature. Post-treatment: Add deionized water, and precipitate is separated out. Filter to obtain white solid. The compound shown in intermediate 1 is obtained (yield 59.2%).

[0119] Second step: Dissolve intermediate 1 (1.0 eq) in 300 mL of anhydrous tetrahydrofuran, and stir at -78°C for 30 minutes under nitrogen protection. Inject n-butyllithium (2.5 mol / L) (2.5 eq) and react for 2 hours. Then add raw material 3 (1.0 eq) and react at low temperature for 4 hours. Place the reaction bottle at room temperature and react overnight. Post-treatment: Add 70 mL of deionized water and stir for 10 minutes. Separate the layers, extract the water layer with ethyl acetate once, combine the organic layers, and dry over anhydrous magnesium sulfate. Spin dry to obtain yellow oil, and purify by column chromatography. Elute the target product with dichloromethane: petroleum ether (V:V) = 1:2, and spin dry to obtain colorless oil intermediate 2 (yield 57.3%).

[0120] Third step: Dissolve intermediate 2 (1.0 eq) in 300 mL of dichloromethane, and stir at 0°C for 30 minutes. Add methanesulfonic acid (5.0 eq) to the reaction solution under nitrogen protection, and react for 1 h. Then increase the temperature to room temperature, react for 4 h, and complete the reaction. Post-treatment: Solid is separated out, filter, and obtain white solid. Wash with petroleum ether and dry to obtain intermediate 3 (yield 78.1%).

[0121] Fourth step: Intermediate 3 (1.0 eq) and raw material 4 (1.1 eq) were added to the reaction bottle, then palladium catalyst (0.01 eq), phosphine ligand (0.05 eq) and cesium carbonate (2.0 eq) were added, and finally 200 mL of toluene, 100 mL of ethanol and 100 mL of deionized water were added. Nitrogen protection, 90°C reaction for 24 hours. Post-processing process: cooling, static separation, washing the organic layer once with water, purifying the product by column, eluting the target product with dichloromethane: petroleum ether (V:V) = 1:1, collecting the product point, and drying to obtain the target product ET-97 (yield 52.3%).

[0122] The obtained compound ET-97 was detected and analyzed, and the results were as follows:

[0123] HPLC purity: >99%.

[0124] Mass calculated value: 618.75; mass test value: 618.93;

[0125] Elemental analysis:

[0126] The calculated value is: C, 83.47; H, 4.24; N, 4.53; O, 2.59; S, 5.18.

[0127] The test value is: C, 85.69; H, 4.56; N, 4.72; O, 2.73; S, 5.24.

[0128] Example 4

[0129]

[0130] First step: Dissolve raw material 1 (1.0 eq) in 500 mL of DMF, add raw material 2 (1.0 eq), nitrogen protection, add cuprous iodide (0.5 eq), potassium phosphate (3.0 eq), and gradually increase the temperature to 150°C. Room temperature overnight, TLC method to determine the reaction is complete, and then cool to room temperature. Post-processing process: add deionized water, precipitate is separated out, filter, get white solid. The compound shown in intermediate 1 is obtained (yield 56.4%).

[0131] Second step: Intermediate 1 (1.0 eq) was dissolved in 300 mL of anhydrous tetrahydrofuran, and stirred for 30 minutes under nitrogen protection at -78°C. n-Butyllithium (2.5 mol / L) (2.5 eq) was injected into the reaction solution, and the reaction was allowed to proceed for 2 hours. Then, raw material 3 (1.0 eq) was added, and the reaction was allowed to proceed for 4 hours at low temperature. The reaction bottle was allowed to stand at room temperature overnight. The post-treatment process was as follows: 70 mL of deionized water was added, and stirred for 10 minutes. The liquid was separated, and the water layer was extracted with ethyl acetate once. The organic layers were combined, and dried over anhydrous magnesium sulfate. The yellow oil obtained after rotary evaporation was purified by column chromatography, and the target product was eluted with dichloromethane: petroleum ether (V:V) = 1:2. The colorless oil obtained after rotary evaporation was intermediate 2 (yield 61.1%).

[0132] Third step: Intermediate 2 (1.0 eq) was dissolved in 300 mL of dichloromethane, and stirred for 30 minutes at 0°C. Methyl sulfonic acid (5.0 eq) was added to the reaction solution under nitrogen protection, and the reaction was allowed to proceed for 1 hour. Then, the reaction was allowed to warm up to room temperature, and the reaction was allowed to proceed for 4 hours. The post-treatment process was as follows: solid was precipitated, and filtered. The white solid obtained after washing with petroleum ether was dried to obtain intermediate 3 (yield 78.8%).

[0133] Fourth step: Intermediate 3 (1.0 eq) and raw material 4 (1.1 eq) were added to the reaction bottle, and then palladium catalyst (0.01 eq), phosphine ligand (0.05 eq), and cesium carbonate (2.0 eq) were added. Finally, 200 mL of toluene, 100 mL of ethanol, and 100 mL of deionized water were added, and the reaction was allowed to proceed for 24 hours at 90°C under nitrogen protection. The post-treatment process was as follows: the temperature was lowered, and the liquid was allowed to stand to separate. The organic layer was washed with water once. The product was purified by column chromatography, and the target product was eluted with dichloromethane: petroleum ether (V:V) = 1:1. The product was collected at the product point, and rotary evaporation was performed to obtain the target product ET-129 (yield 50.4%).

[0134] The obtained compound ET-129 was subjected to detection analysis, and the results were as follows:

[0135] HPLC purity: >99%.

[0136] Mass spectrometry calculation value: 628.78; mass spectrometry test value: 628.97;

[0137] Elemental analysis:

[0138] The calculation value was: C, 87.87; H, 5.13; N, 4.46; O, 2.54.

[0139] The test value was: C, 87.24; H, 5.47; N, 4.68; O, 2.79.

[0140] Examples 5-26

[0141] The synthesis of the following compounds was accomplished according to the synthetic procedure of Examples 1 to 4, whose molecular formula and mass spectrum data are shown in Table 1 below.

[0142] Table 1 Molecular formula and mass spectrum

[0143]

[0144]

[0145] Application Example 1

[0146] Preparation of an organic electroluminescent device:

[0147] a. ITO anode: ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 150 nm was cleaned in distilled water for 2 times, ultrasonic washing for 30 min, and then cleaned repeatedly in distilled water for 2 times, ultrasonic washing for 10 min. After washing, the substrate was baked in a vacuum oven at 220°C for 2 hours, and then cooled down for use. The substrate was used as an anode, and other functional layers were vacuum deposited on it using a vapor deposition machine.

[0148] b. HIL (hole injection layer): The hole injection layer material HT and P-dopant were vacuum deposited at a deposition rate of 0.1 nm / s, and their chemical formula is shown below. The deposition rate ratio of HT to P-dopant was 98:2, and the thickness was 10 nm.

[0149] c. HTL (hole transport layer): The hole transport layer HT was vacuum deposited on the hole injection layer at a deposition rate of 0.1 nm / s, and the thickness was 120 nm.

[0150] d. Light-emitting auxiliary layer: The prime was vacuum deposited on the hole transport layer as a light-emitting auxiliary layer at a deposition rate of 0.1 nm / s, and the thickness was 5 nm.

[0151] e. EML (emitting layer): Then, the host material (Host) and the dopant material (Dopant) were vacuum deposited on the light-emitting auxiliary layer as an emitting layer at a deposition rate of 0.1 nm / s, and the thickness was 25 nm. The chemical formula of the Host and the Dopant is shown below. The deposition rate ratio of the Host to the Dopant was 95:5.

[0152] f. HB (hole blocking layer): The HB was vacuum deposited as a hole blocking layer at a deposition rate of 0.1 nm / s, and the thickness was 5.0 nm.

[0153] g. ETL (electron transport layer): The electron transport layer was vacuum deposited at a deposition rate of 0.1 nm / s, and the thickness was 20 nm. ​​​​​The compound 1 and Liq were vacuum evaporated at a rate of 35 nm, and the compound 1 and Liq were used as the electron transport layer. The evaporation rate ratio of the compound 1 and Liq was 50:50.

[0154] h、EIL (electron injection layer): The compound 1 was vacuum evaporated at a rate of 1.0 nm to form the electron injection layer. The compound 1 was vacuum evaporated at a rate of 1.0 nm to form the electron injection layer.

[0155] i、Cathode: Magnesium and silver were vacuum evaporated at a rate of 18 nm, and the evaporation rate ratio of magnesium and silver was 1:9 to obtain the OLED device. The compound 1 and Liq were vacuum evaporated at a rate of 35 nm, and the compound 1 and Liq were used as the electron transport layer. The evaporation rate ratio of the compound 1 and Liq was 50:50.

[0156] j、Light extraction layer: The CPL was vacuum evaporated at a rate of 70 nm on the cathode as the light extraction layer. The CPL was vacuum evaporated at a rate of 70 nm on the cathode as the light extraction layer.

[0157] k、The substrate on which the evaporation was completed was packaged. First, the cleaned cover plate was coated with UV glue by using a coating device, then the coated cover plate was moved to the pressing section, the substrate on which the evaporation was completed was placed on the end of the cover plate, and finally the substrate and the cover plate were bonded under the action of the bonding device, and the UV glue was cured by light at the same time.

[0158] Device structure:

[0159] ITO / Ag / ITO / HT:P-dopant (10 nm, 2%) / HT (120 nm) / prime (5 nm) / Host:Dopant (25 nm, 5%) / HB (5 nm) / ET:Liq (35 nm, 50%) / Yb (1 nm) / Mg:Ag (18 nm, 1:9) / CPL (70 nm).

[0160]

[0161]

[0162] Application Example 2-26

[0163] The organic electroluminescence device of application example 2-26 was prepared according to the above preparation method of the organic electroluminescence device, except that the compound 1 in application example 1 was replaced by the corresponding compound to form the electron transport layer.

[0164] Comparative Example 1

[0165] The organic electroluminescence device was prepared according to the above preparation method of the organic electroluminescence device, except that the compound 1 in application example 1 was replaced by the comparative compound a.

[0166] Comparative Example 2

[0167] An organic electroluminescence device was produced according to the above production method of an organic electroluminescence device, except that the compound 1 in Application Example 1 was replaced with Comparative Compound b.

[0168] Comparative Example 3

[0169] An organic electroluminescence device was produced according to the above production method of an organic electroluminescence device, except that the compound 1 in Application Example 1 was replaced with Comparative Compound c.

[0170] Comparative Example 4

[0171] An organic electroluminescence device was produced according to the above production method of an organic electroluminescence device, except that the compound 1 in Application Example 1 was replaced with Comparative Compound d.

[0172] Comparative Example 5

[0173] An organic electroluminescence device was produced according to the above production method of an organic electroluminescence device, except that the compound 1 in Application Example 1 was replaced with Comparative Compound e.

[0174] Comparative Example 6

[0175] An organic electroluminescence device was produced according to the above production method of an organic electroluminescence device, except that the compound 1 in Application Example 1 was replaced with Comparative Compound f.

[0176]

[0177] The driving voltage, luminous efficiency, BI value and lifespan of the light-emitting devices obtained in the above Application Examples 1-26 and Comparative Examples 1-6 were characterized at a brightness of 1000 (nits), and the test results are shown in Table 2 below.

[0178] Table 2 Test results of light-emitting properties (brightness value is 1000 nits)

[0179]

[0180]

[0181] As known to those skilled in the art, the blue light organic electroluminescence device is affected by the microcavity effect, and the luminous efficiency is greatly affected by the chromaticity. Therefore, the BI value is introduced as the basis for the efficiency of the blue light emitting material, BI = luminous efficiency / CIEy. In the art, the short lifespan and low efficiency of the blue light device have been one of the problems that those skilled in the art urgently need to solve.

[0182] As can be seen from Table 2, compared with the existing organic electroluminescent devices provided in Comparative Examples 1 to 4, the light-emitting devices prepared using the electron transport material provided by the present invention in Application Examples 1 to 26 show improvements in driving voltage, luminous efficiency, BI, and lifetime. The electroluminescent devices of the present invention have a driving voltage as low as 3.68V or less, a luminous efficiency as high as 6.57cd / A or more, a lifetime as high as 178h or more, and a BI value as high as 145 or more.

[0183] From the perspective of device performance, comparing compound a with compound ET-18, the aryl group in the parent core of ET-018 results in a planar structure, leading to greater steric hindrance and affecting the overall molecular configuration and packing density, thus impacting OLED device performance. The presence of the benzene ring improves the device's luminous efficiency by 7%, a significant improvement already achieved in blue light devices in this field. Comparing compound c with compound ET-141, ET-18 has a phenylcyanopyridine side chain, while compound c lacks the specific cyano functional group. Device data shows that the presence of the cyano group improves both the efficiency and lifetime of the blue light device.

[0184] Specifically, triazine, pyridine, and pyrimidine are functional groups with strong electron-withdrawing capabilities, which can effectively improve the electron mobility of electron transport materials. Furthermore, the use of specific functional groups containing cyano groups can further enhance the electron mobility of electron transport materials, improve the electron-hole imbalance problem inside organic electroluminescent devices, and at the same time ensure the high triplet energy level (ET) and wide bandgap of the material, thereby further improving the luminous efficiency, improving the energy level matching degree of each layer of the device, reducing the driving voltage, and extending the device lifetime. Compared with existing technologies, it has superior device performance.

[0185] The applicant declares that the above embodiments illustrate the organic compounds and their applications, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An organic compound characterized in that, The organic compound is any one of the following compounds:

2. An electron transport material, characterized by, The electron transport material includes any one of the organic compounds of claim 1 or a combination of at least two.

3. An organic electroluminescent device, characterized by comprising The organic electroluminescent device includes a first electrode, a second electrode, and an organic thin film layer disposed between the first electrode and the second electrode. The organic thin film layer includes an electron transport layer including the organic compound of claim 1.

4. The organic electroluminescent device according to claim 3, characterized in that The organic thin film layer further includes any one of 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 injection layer, or a capping layer or a combination of at least two.

5. A display panel, characterized by, The display panel includes the organic electroluminescent device of claim 3 or 4.

6. An electronic device, comprising: The electronic device includes the display panel of claim 5.

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