Organic compound, method for preparing the same, light-emitting auxiliary material, and organic electroluminescent device

Abstract

The present application relates to the technical field of light-emitting material, in particular to an organic compound, a preparation method thereof, a light-emitting auxiliary material and an organic electroluminescent device. The structural formula of the organic compound is shown in the following general formula I: wherein X is selected from O or S; Ar is selected from substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl, Ar is fused with the adjacent benzene ring and the ring; R1 is selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl; L is selected from a connecting bond or a group shown in the following formula I; Ar1 and Ar2 are each independently selected from substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl. The organic electroluminescent device prepared from the organic compound has reduced driving voltage, and the luminous efficiency and the service life are both improved.

Description

Technical Field

[0001] The present invention relates to the technical field of luminescent materials, and in particular to organic compounds and preparation methods thereof, luminescent auxiliary materials and organic electroluminescent devices. Background Art

[0002] OLED materials are divided into luminescent materials, hole transport materials, and electron transport materials. Hole transport materials typically have low highest occupied molecular orbital (HOMO) values, causing excitons generated in the luminescent layer to diffuse to the hole transport layer interface or to the side of the hole transport layer. This ultimately leads to luminescence at the interface within the luminescent layer or charge imbalance within the luminescent layer, resulting in light emission at the hole transport layer interface. This reduces the color purity and efficiency of the organic electroluminescent device, as well as shortens its lifespan.

[0003] Introducing a light-emitting auxiliary layer between the light-emitting layer and the hole transport layer can effectively avoid the above technical problems.

[0004] Currently, there are limited materials available for light-emitting auxiliary layers. Most of these materials use a fluorene ring structure, which has a high hole mobility and a high T1 energy that blocks the excitons after recombination from expanding to the transport layer, thereby improving the overall efficiency of the device. At the same time, the appropriate HOMO value reduces the transmission barrier of holes from the transport layer to the light-emitting layer, thereby reducing the device driving voltage and improving the lifespan.

[0005] Research on organic electroluminescent materials has been widely carried out in academia and industry, but so far, stable and efficient organic layer materials for organic electrical components have not been fully developed, and the industrialization process of this technology still faces many key issues. Therefore, how to develop a new luminescent auxiliary material has always been an urgent problem to be solved by technicians in this field.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] The purpose of the present invention is to provide an organic compound and a preparation method thereof, a luminescence auxiliary material, and an organic electroluminescent device. The organic electroluminescent device prepared using the organic compound provided in the embodiment of the present invention reduces the driving voltage while improving the luminous efficiency and lifespan.

[0008] The present invention is achieved in that:

[0009] In a first aspect, an embodiment of the present invention provides an organic compound, the structural formula of which is shown in the following general formula I:

[0010] wherein X is selected from O or S;

[0011] Ar is selected from substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl, Ar is fused with the adjacent benzene ring, and Ar is fused with the 1, 2, 2, 3, or 3, 4 positions on the benzene ring;

[0012] R1 is any one selected from the group consisting of hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl;

[0013] L is selected from a connecting bond or a group represented by the following formula I;

[0014] wherein R3 is selected from any one of the functional groups consisting of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl;

[0015] Ar1 and Ar2 are the same as or different from each other and are independently selected from any one of the functional groups consisting of substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl.

[0016] In a second aspect, an embodiment of the present invention provides a method for preparing the above-mentioned organic compound, comprising: preparing the organic compound according to the following synthesis path:

[0017]

[0018] In a third aspect, an embodiment of the present invention provides a luminescence-assisting material for preparing a luminescence-assisting layer, which includes the above-mentioned organic compound.

[0019] In a fourth aspect, an embodiment of the present invention provides an organic electroluminescent device, which includes a luminescence-assisting layer prepared by the above-mentioned organic compound or the above-mentioned luminescence-assisting material for preparing the luminescence-assisting layer.

[0020] The present invention has the following beneficial effects: after the organic compound provided by the embodiment of the present invention is used to prepare an organic electroluminescent device, the driving voltage of the organic electroluminescent device is reduced while the luminous efficiency and lifespan are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 This is the H NMR spectrum of the intermediate 2 provided in Example 1 of the present invention;

[0023] Figure 2 This is the H NMR spectrum of compound 1 provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0024] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0025] An embodiment of the present invention provides an organic compound, the structural formula of which is shown in the following general formula I:

[0026] wherein X is selected from O or S;

[0027] Ar is selected from substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl, Ar is fused with the adjacent benzene ring, and Ar is fused with the 1, 2, 2, 3, or 3, 4 positions on the benzene ring;

[0028] R1 is any one selected from the group consisting of hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl;

[0029] L is selected from a connecting bond or a group represented by the following formula I;

[0030] wherein R3 is selected from any one of the functional groups consisting of substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl;

[0031] Ar1 and Ar2 are the same as or different from each other and are independently selected from any one of the functional groups consisting of substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, and substituted or unsubstituted heteroaryl.

[0032] The organic compound provided in the embodiment of the present invention can improve the hole mobility of the compound and change the spatial structure by changing the side chain and extending the molecular conjugation, thereby being more adaptable to the device, effectively improving the lifespan and luminous efficiency of the OLED device while reducing the driving voltage.

[0033] Furthermore, Ar is selected from a substituted or unsubstituted C6-C30 aryl group or a substituted or unsubstituted 3-20 membered heteroaryl group; and Ar is fused with the benzene ring, and Ar is fused with the 1, 2, 2, 3, or 3, 4 positions on the benzene ring; wherein the heteroatom in the heteroaryl group is selected from at least one of oxygen, nitrogen and sulfur; for example, Ar is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthracenyl and phenanthrenyl; and Ar is fused with the adjacent benzene ring; Ar is fused with the 1, 2, 2, 3, or 3, 4 positions on the benzene ring.

[0034] Further, R1 is selected from any one of the functional group consisting of hydrogen, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C3-C30 cycloalkyl, substituted or unsubstituted 3-30 membered heterocycloalkyl, substituted or unsubstituted C6-C30 aryl and substituted or unsubstituted 3-30 membered heteroaryl; wherein the heteroatoms in the heteroaryl and heterocycloalkyl are each independently selected from at least one of oxygen, nitrogen and sulfur;

[0035] Preferably, R1 is selected from any one of the groups represented by the following structural formulas:

[0036]

[0037] Further, L is selected from a connecting bond or a group represented by the following formula I;

[0038] wherein R3 is selected from any one of the functional groups consisting of a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C1-C30 alkoxy group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted 3-30 membered heterocycloalkyl group, a substituted or unsubstituted C6-C30 aryl group, and a substituted or unsubstituted 3-30 membered heteroaryl group; wherein the heteroatoms in the heteroaryl group and the heterocycloalkyl group are each independently selected from at least one of oxygen, nitrogen, and sulfur;

[0039] Preferably, L is selected from any one of a connecting bond or a group represented by the following structural formula:

[0040]

[0041] Furthermore, Ar1 and Ar2 are the same as or different from each other and are each independently selected from any one of the functional group consisting of a substituted or unsubstituted 3-30 membered heterocycloalkyl, a substituted or unsubstituted C6-C30 aryl and a substituted or unsubstituted 3-30 membered heteroaryl, wherein the heteroatoms in the heteroaryl and heterocycloalkyl are each independently selected from at least one of oxygen, nitrogen and sulfur;

[0042] Preferably, Ar1 and Ar2 are each independently selected from any one of the groups shown in the following structural formulas and any combination of the following groups:

[0043]

[0044] Furthermore, the organic compound is selected from any one of the compounds represented by the following general formula II-1 to general formula II-9:

[0045]

[0046] It should be noted that: (1) the selection of L, X, R1, Ar1 and Ar2 in general formula II-1 to general formula II-9 is the same as that in the above general formula I.

[0047] (2) The “*” in the structural formula provided in the embodiment of the present invention represents a connection point.

[0048] (3) The term "substituted" as provided in the embodiments of the present invention means substituted by one, two or more substituents selected from the group consisting of C1-C20 alkyl, C1-C20 alkoxy, C6-C30 aryl, and C6-C30 heteroaryl, wherein the heteroatom is selected from oxygen, nitrogen, and sulfur.

[0049] (4) The substituted or unsubstituted alkyl group or C1-C20 alkyl group or substituted or unsubstituted C1-C30 alkyl group provided in the embodiments of the present invention include, but are not limited to, methyl, ethyl, propyl, isopropyl, and tert-butyl alkyl groups, and may also be other alkyl groups.

[0050] The substituted or unsubstituted cycloalkyl group or the substituted or unsubstituted C3-C30 cycloalkyl group includes, but is not limited to, cyclopropyl, cyclobutyl, and cyclopentyl.

[0051] The substituted or unsubstituted heterocycloalkyl group or the substituted or unsubstituted 3- to 30-membered heterocycloalkyl group include, but are not limited to, epoxypropyl, epoxybutyl, and epoxypentyl groups.

[0052] The substituted or unsubstituted aryl group or the substituted or unsubstituted C6-C30 aryl group includes, but is not limited to, phenyl, benzyl, p-methylphenyl, m-methylphenyl, and the like.

[0053] The substituted or unsubstituted heteroaryl group or the substituted or unsubstituted 3- to 30-membered heteroaryl group includes, but is not limited to, furan, thiophene, quinoline, and pyrrole.

[0054] The organic compound is selected from any one of the compounds represented by the following structural formulas:

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068] It should be noted that the numbers of the compounds listed above are the numbers of the compounds corresponding to the following examples.

[0069] In a second aspect, an embodiment of the present invention provides a method for preparing the above-mentioned organic compound, comprising: preparing the organic compound according to the following synthesis path:

[0070]

[0071] In the above synthesis route, R1, X, L, Ar1 and Ar2 are identical to those in the above general formula I, and Hal1, Hal2 and Hal3 are each independently selected from fluorine, chlorine, bromine or iodine. The specific process is as follows:

[0072] (1) After raw materials A and B are dissolved in toluene, Pd2(dba)3, P(t-Bu)3 and t-BuONa are added under N2 atmosphere, the temperature is raised to 110-120°C and stirred for reaction for 8-12 hours. After the reaction is completed, diatomaceous earth is used for hot filtration to remove salt and catalyst. After the filtrate is cooled to room temperature, distilled water is added to the filtrate for washing. After separation, the organic phase is retained, the aqueous phase is extracted with ethyl acetate, and the combined organic layer is dried with magnesium sulfate. The solvent is removed using a rotary evaporator. Finally, a mixture of dichloromethane and petroleum ether is used as an eluent, and the remaining substance is purified by column chromatography to obtain the compound shown in Intermediate 1.

[0073] (2) After the intermediate 1 and the raw material C are dissolved in toluene, Pd2(dba)3, P(t-Bu)3 and t-BuONa are added under a N2 atmosphere, the temperature is raised to 110-120°C and the reaction is stirred for 8-12 hours. After the reaction is completed, the salt and catalyst are removed by hot filtration using diatomaceous earth. After the filtrate is cooled to room temperature, distilled water is added to the filtrate for washing. After separation, the organic phase is retained, the aqueous phase is extracted with ethyl acetate, and the combined organic layer is dried with magnesium sulfate, and the solvent is removed using a rotary evaporator. Finally, the remaining substance is purified by column chromatography using a mixture of dichloromethane and petroleum ether as an eluent to obtain the compound represented by intermediate 2.

[0074] In this reaction step, the raw material C contains two halogens. By utilizing the characteristics of the reaction activity I>Br>Cl in the Buchwald-Hartwig coupling reaction, the preparation of the target structural intermediate is achieved, and the reaction is purified by column chromatography or silica gel funnel to remove by-products to obtain the target compound.

[0075] For the reaction mechanism, see Robert H. Crabtree's "Transition Metal Organic Chemistry" (Sixth Edition), published by East China University of Science and Technology Press in Shanghai, September 0, 2017, ISBN: 978-7-5628-5111-0, page 388. Chen Runfeng's "Organic Chemistry and Photoelectric Materials Experimental Course," published by Southeast University Press in November 2019, ISBN: 9787564184230, page 174.

[0076] (3) Under N2 protection, intermediate 2, raw material D, tetrakis(triphenylphosphine)palladium and potassium carbonate are added to a mixed solvent of toluene, ethanol and water, respectively, and the temperature is raised to 90-100°C for reaction for 8-10 hours. After the reaction is completed, the mixture is cooled to room temperature. After the solid is precipitated, it is filtered and washed with water to remove salt. The solid is then rinsed with a small amount of ethanol, the filter cake is dried, and the remaining substance is purified by column chromatography using a mixture of dichloromethane and petroleum ether as an eluent to obtain the compound represented by the above general formula I.

[0077] In a third aspect, an embodiment of the present invention provides a luminescence-assisting material for preparing a luminescence-assisting layer, which includes the above-mentioned organic compound.

[0078] In a fourth aspect, an embodiment of the present invention provides an organic electroluminescent device, which includes a luminescence-assisting layer prepared by the above-mentioned organic compound or the above-mentioned luminescence-assisting material for preparing the luminescence-assisting layer.

[0079] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0080] Example 1

[0081] The present invention provides an organic compound (denoted as Compound 1) and a preparation method thereof, wherein the preparation method is as follows:

[0082] Organic compounds were synthesized according to the following synthetic routes:

[0083] Specifically:

[0084] After raw material A (1.0 eq) and raw material B (1.0 eq) were dissolved in toluene, Pd2(dba)3 (0.02 eq), P(t-Bu)3 (0.05 eq) and t-BuONa (2.0 eq) were added under a N2 atmosphere, and the temperature was raised to 120°C and stirred for 12 hours. After the reaction, the salt and catalyst were removed by hot filtration using diatomaceous earth. After the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing. After separation, the organic phase was retained, and the aqueous phase was extracted with ethyl acetate. The combined organic layers were dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Finally, the remaining substance was purified by column chromatography using a mixture of dichloromethane and petroleum ether (V:V = 1:20) as an eluent to obtain the compound shown in Intermediate 1 (yield: 76.35%);

[0085] Intermediate 1 (1.0 eq) and raw material C (1.0 eq) were dissolved in toluene, and Pd2(dba)3 (0.02 eq), P(t-Bu)3 (0.05 eq) and t-BuONa (2.0 eq) were added under a N2 atmosphere. The temperature was raised to 120°C and stirred for 8 hours. After the reaction, the mixture was filtered while hot using diatomaceous earth to remove salt and catalyst. The filtrate was cooled to room temperature, and distilled water was added to the filtrate for washing. After separation, the organic phase was retained, and the aqueous phase was extracted with ethyl acetate. The combined organic layers were dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Finally, the remaining substance was purified by column chromatography using a mixture of dichloromethane and petroleum ether (V:V=1:14) as an eluent to obtain the compound shown in Intermediate 2 (yield: 62.19%). The nuclear magnetic hydrogen spectrum of Intermediate 2 can be found in Figure 1 .

[0086] Under N2 protection, intermediate 2 (1.0 eq), raw material D (1.1 eq), tetrakis(triphenylphosphine)palladium (0.01 eq) and potassium carbonate (2.0 eq) were respectively added to a mixed solvent of toluene, ethanol and water, and the temperature was raised to 100°C for 10 h. After the reaction, the mixture was cooled to room temperature. After the solid was precipitated, it was filtered and washed with water to remove salt. It was then rinsed with a small amount of ethanol, the filter cake was dried, and the remaining substance was purified by column chromatography using a mixture of dichloromethane and petroleum ether (V:V = 1:10) as eluent to obtain compound 1; (yield: 58.60%, Mw: 689.86).

[0087] The compound 1 was characterized and its H NMR spectrum is shown in Figure 2 , its mass spectrum and elemental analysis data are as follows:

[0088] Mass spectrometry test: theoretical value is 689.86; tested value is 690.06.

[0089] Elemental analysis:

[0090] Calculated values: C, 90.54; H, 5.11; N, 2.03; O, 2.32.

[0091] Found: C, 90.21; H, 5.39; N, 2.24; O, 2.47.

[0092] It can be seen that the structural formula of the prepared compound is the structural formula of compound 1 shown in the synthesis route.

[0093] Example 2

[0094] The present invention provides an organic compound (denoted as Compound 23) and a preparation method thereof, wherein the preparation method is as follows:

[0095] Organic compounds were synthesized according to the following synthetic routes:

[0096] The details are as follows:

[0097] After raw material A (1.0 eq) and raw material B (1.0 eq) were dissolved in toluene, Pd2(dba)3 (0.02 eq), P(t-Bu)3 (0.05 eq) and t-BuONa (2.0 eq) were added under a N2 atmosphere, and the temperature was raised to 120°C and stirred for 12 hours. After the reaction, diatomaceous earth was used for hot filtration to remove salt and catalyst. After the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing. After separation, the organic phase was retained, and the aqueous phase was extracted with ethyl acetate. The combined organic layers were dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Finally, a mixture of dichloromethane and petroleum ether (V:V = 1:20) was used as an eluent, and the remaining substance was purified by column chromatography to obtain the compound shown in Intermediate 1 (yield: 73.49%);

[0098] After intermediate 1 (1.0 eq) and raw material C (1.0 eq) were dissolved in toluene, Pd2(dba)3 (0.02 eq), P(t-Bu)3 (0.05 eq) and t-BuONa (2.0 eq) were added under a N2 atmosphere, the temperature was raised to 120°C and stirred for 8 hours. After the reaction, diatomaceous earth was used for hot filtration to remove salt and catalyst. After the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing. After separation, the organic phase was retained, the aqueous phase was extracted with ethyl acetate, and the combined organic layers were dried over magnesium sulfate. The solvent was removed using a rotary evaporator. Finally, a mixture of dichloromethane and petroleum ether (V:V = 1:14) was used as an eluent, and the remaining substance was purified by column chromatography to obtain the compound shown in intermediate 2 (yield: 63.47%).

[0099] Under N2 protection, intermediate 2 (1.0 eq), raw material D (1.1 eq), tetrakistriphenylphosphine palladium (0.01 eq) and potassium carbonate (2.0 eq) were respectively added to a mixed solvent of toluene, ethanol and water, and the temperature was raised to 100°C for 10 h. After the reaction, the mixture was cooled to room temperature. After the solid was precipitated, it was filtered and washed with water to remove salt. It was then rinsed with a small amount of ethanol, the filter cake was dried, and the remaining substance was purified by column chromatography using a mixture of dichloromethane and petroleum ether (V:V = 1:10) as eluent to obtain compound 23; (yield: 57.22%, Mw: 713.88).

[0100] The obtained compound 23 was characterized, and the results were as follows:

[0101] Mass spectrometry test: theoretical value is 713.88; tested value is 713.95.

[0102] Elemental analysis:

[0103] Calculated values: C, 90.85; H, 4.94; N, 1.96; O, 2.24.

[0104] Found: C, 90.34; H, 5.37; N, 2.25; O, 2.47.

[0105] Example 3

[0106] The present invention provides an organic compound (denoted as Compound 55) and a preparation method thereof, wherein the preparation method is as follows:

[0107] Organic compounds were synthesized according to the following synthetic routes:

[0108] The details are as follows:

[0109] Raw material A (1.0 eq) and raw material B (1.0 eq) were dissolved in toluene, and Pd2(dba)3 (0.02 eq), P(t-Bu)3 (0.05 eq) and t-BuONa (2.0 eq) were added under a N2 atmosphere. The temperature was raised to 120°C and stirred for 12 hours. After the reaction, the salt and catalyst were removed by hot filtration using diatomaceous earth. After the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing. After separation, the organic phase was retained, and the aqueous phase was extracted with ethyl acetate. The combined organic layers were dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Finally, the remaining substance was purified by column chromatography using a mixture of dichloromethane and petroleum ether (V:V = 1:20) as an eluent to obtain the compound shown in Intermediate 1 (yield: 77.04%).

[0110] After intermediate 1 (1.0 eq) and raw material C (1.0 eq) were dissolved in toluene, Pd2(dba)3 (0.02 eq), P(t-Bu)3 (0.05 eq) and t-BuONa (2.0 eq) were added under a N2 atmosphere, the temperature was raised to 120°C and stirred for 8 hours. After the reaction, diatomaceous earth was used for hot filtration to remove salt and catalyst. After the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing. After separation, the organic phase was retained, the aqueous phase was extracted with ethyl acetate, and the combined organic layers were dried over magnesium sulfate. The solvent was removed using a rotary evaporator. Finally, a mixture of dichloromethane and petroleum ether (V:V = 1:14) was used as an eluent, and the remaining substance was purified by column chromatography to obtain the compound shown in intermediate 2 (yield: 67.26%).

[0111] Under N2 protection, intermediate 2 (1.0 eq), raw material D (1.1 eq), tetrakistriphenylphosphine palladium (0.01 eq) and potassium carbonate (2.0 eq) were respectively added to a mixed solvent of toluene, ethanol and water, and the temperature was raised to 100°C for reaction for 10 h. After the reaction, the mixture was cooled to room temperature. After the solid was precipitated, it was filtered and washed with water to remove salt. It was then rinsed with a small amount of ethanol, the filter cake was dried, and the remaining substance was purified by column chromatography using a mixture of dichloromethane and petroleum ether (V:V = 1:10) as eluent to obtain compound 55; (yield: 59.14%, Mw: 689.86).

[0112] The obtained compound-55 was characterized, and the results were as follows:

[0113] Mass spectrometry test: theoretical value is 689.86; tested value is 689.99.

[0114] Elemental analysis:

[0115] Calculated values: C, 90.54; H, 5.11; N, 2.03; O, 2.32.

[0116] Found: C, 90.27; H, 5.36; N, 2.26; O, 2.43.

[0117] Example 4

[0118] The present invention provides an organic compound (denoted as Compound 153) and a preparation method thereof, wherein the preparation method is as follows:

[0119] Organic compounds were synthesized according to the following synthetic routes:

[0120] The details are as follows:

[0121] Raw material A (1.0 eq) and raw material B (1.0 eq) were dissolved in toluene, and Pd2(dba)3 (0.02 eq), P(t-Bu)3 (0.05 eq) and t-BuONa (2.0 eq) were added under a N2 atmosphere. The temperature was raised to 120°C and stirred for 12 hours. After the reaction, the salt and catalyst were removed by hot filtration using diatomaceous earth. The filtrate was cooled to room temperature, and distilled water was added to the filtrate for washing. After separation, the organic phase was retained, and the aqueous phase was extracted with ethyl acetate. The combined organic layers were dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Finally, the remaining substance was purified by column chromatography using a mixture of dichloromethane and petroleum ether (V:V = 1:20) as an eluent to obtain the compound shown in Intermediate 1 (yield: 71.25%).

[0122] After intermediate 1 (1.0 eq) and raw material C (1.0 eq) were dissolved in toluene, Pd2(dba)3 (0.02 eq), P(t-Bu)3 (0.05 eq) and t-BuONa (2.0 eq) were added under a N2 atmosphere, the temperature was raised to 120°C and stirred for 8 hours. After the reaction, diatomaceous earth was used for hot filtration to remove salt and catalyst. After the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing. After separation, the organic phase was retained, the aqueous phase was extracted with ethyl acetate, and the combined organic layers were dried over magnesium sulfate. The solvent was removed using a rotary evaporator. Finally, a mixture of dichloromethane and petroleum ether (V:V = 1:14) was used as an eluent, and the remaining substance was purified by column chromatography to obtain the compound shown in intermediate 2 (yield: 62.37%).

[0123] Under N2 protection, intermediate 2 (1.0 eq), raw material D (1.1 eq), tetrakistriphenylphosphine palladium (0.01 eq) and potassium carbonate (2.0 eq) were respectively added to a mixed solvent of toluene, ethanol and water, and the temperature was raised to 100°C for 10 h. After the reaction, the mixture was cooled to room temperature. After the solid was precipitated, it was filtered and washed with water to remove salt. It was then rinsed with a small amount of ethanol, the filter cake was dried, and the residual substance was purified by column chromatography using a mixture of dichloromethane and petroleum ether (V:V = 1:10) as eluent to obtain compound 153; (yield: 57.21%, Mw: 689.86).

[0124] The obtained compound 153 was characterized, and the results are as follows:

[0125] Mass spectrometry test: theoretical value is 689.86; tested value is 690.07.

[0126] Elemental analysis:

[0127] Calculated values: C, 90.54; H, 5.11; N, 2.03; O, 2.32.

[0128] Found: C, 90.21; H, 5.33; N, 2.21; O, 2.49.

[0129] Example 5

[0130] The present invention provides an organic compound (denoted as Compound 211) and a preparation method thereof, wherein the preparation method is as follows:

[0131] Organic compounds were synthesized according to the following synthetic routes:

[0132] The details are as follows:

[0133] Raw material A (1.0 eq) and raw material B (1.0 eq) were dissolved in toluene, and Pd2(dba)3 (0.02 eq), P(t-Bu)3 (0.05 eq) and t-BuONa (2.0 eq) were added under a N2 atmosphere. The temperature was raised to 120°C and stirred for 12 hours. After the reaction, the salt and catalyst were removed by hot filtration using diatomaceous earth. After the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing. After separation, the organic phase was retained, and the aqueous phase was extracted with ethyl acetate. The combined organic layers were dried over magnesium sulfate, and the solvent was removed using a rotary evaporator. Finally, the remaining substance was purified by column chromatography using a mixture of dichloromethane and petroleum ether (V:V = 1:20) as an eluent to obtain the compound shown in Intermediate 1 (yield: 77.18%).

[0134] After intermediate 1 (1.0 eq) and raw material C (1.0 eq) were dissolved in toluene, Pd2(dba)3 (0.02 eq), P(t-Bu)3 (0.05 eq) and t-BuONa (2.0 eq) were added under a N2 atmosphere, the temperature was raised to 120°C and stirred for 8 hours. After the reaction, diatomaceous earth was used for hot filtration to remove salt and catalyst. After the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing. After separation, the organic phase was retained, the aqueous phase was extracted with ethyl acetate, and the combined organic layers were dried over magnesium sulfate. The solvent was removed using a rotary evaporator. Finally, a mixture of dichloromethane and petroleum ether (V:V = 1:14) was used as an eluent, and the remaining substance was purified by column chromatography to obtain the compound shown in intermediate 2 (yield: 66.38%).

[0135] Under N2 protection, intermediate 2 (1.0 eq), raw material D (1.1 eq), tetrakistriphenylphosphine palladium (0.01 eq) and potassium carbonate (2.0 eq) were respectively added to a mixed solvent of toluene, ethanol and water, and the temperature was raised to 100°C for 10 h. After the reaction, the mixture was cooled to room temperature. After the solid was precipitated, it was filtered and washed with water to remove salt. It was then rinsed with a small amount of ethanol, the filter cake was dried, and the residual substance was purified by column chromatography using a mixture of dichloromethane and petroleum ether (V:V = 1:10) as eluent to obtain compound 211; (yield: 58.91%, Mw: 705.92).

[0136] The obtained compound 211 was characterized, and the results are as follows:

[0137] Mass spectrometry test: theoretical value is 705.92; tested value is 706.22.

[0138] Elemental analysis:

[0139] Calculated values: C, 88.48; H, 5.00; N, 1.98; S, 4.54.

[0140] Found values: C, 88.28; H, 5.26; N, 2.19; S, 4.59.

[0141] The structural formula of the compounds prepared in the above examples is the general formula I in the content of the invention. The synthesis routes and principles of other compounds are the same as those in the above examples, so they are not listed here in detail.

[0142] According to the above preparation method, the organic compounds shown in Table 1 below can be obtained:

[0143] Table 1 Synthesized organic compounds

[0144]

[0145]

[0146] Device Example 1

[0147] This embodiment provides a method for preparing an organic electroluminescent device, which specifically includes the following steps:

[0148] a. ITO anode: Wash the ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 150nm in distilled water twice, ultrasonically wash for 30 minutes, then repeatedly wash it with distilled water twice, ultrasonically wash for 10 minutes, and then transfer it to a spin dryer for drying. Finally, bake it in a vacuum oven at 220℃ for 2 hours. After baking, cool it down and it can be used. Use this substrate as the anode and use an evaporation machine to carry out the evaporation device process, and evaporate other functional layers on it in sequence;

[0149] b. HIL (hole injection layer): The hole injection layer materials HT and P-dopant were vacuum evaporated at a deposition rate of 97:3, and the thickness was 10 nm.

[0150] c. HTL (hole transport layer): At a deposition rate of 100 nm, 120 nm of HT was vacuum-deposited on the hole injection layer as a hole transport layer.

[0151] d. Luminous auxiliary layer: At a deposition rate of , 10 nm of the compound 1 provided in Example 1 was vacuum-deposited on the hole transport layer as a light-emitting auxiliary layer;

[0152] e. EML (light-emitting layer): Then on the above-mentioned light-emitting auxiliary layer, The host material (Host) and dopant material (Dopant) were vacuum-deposited to a thickness of 25 nm as the light-emitting layer. The chemical formulas of the Host and Dopant are shown below. The evaporation rate ratio of the Host and Dopant was 98:2.

[0153] f. HB (hole blocking layer): The hole blocking layer with a thickness of 5.0 nm was vacuum-deposited at a deposition rate of 100 nm.

[0154] g. ETL (Electron Transport Layer): At a deposition rate of , ET and Liq were vacuum-deposited with a thickness of 30 nm as an electron transport layer. The chemical formula of ET is shown below; wherein the deposition rate ratio of ET to Liq is 50:50;

[0155] h. EIL (electron injection layer): The evaporation rate is 1.0 nm, and a Yb film layer is evaporated to form an electron injection layer;

[0156] i. Cathode: 18 nm of magnesium and silver were evaporated at a deposition rate ratio of 1:9 to obtain an OLED device;

[0157] j. Light extraction layer: At a deposition rate of , a CPL with a thickness of 70 nm was vacuum-deposited on the cathode as a light extraction layer;

[0158] k. Package the vapor-deposited substrate: First, use the glue coating equipment to coat the cleaned cover with UV glue, then move the coated cover to the pressing section, place the vapor-deposited substrate on the upper end of the cover, and finally bond the substrate and cover with the bonding equipment, and complete the light curing of the UV glue at the same time.

[0159] The structural formula of the substances involved in the above steps is as follows:

[0160]

[0161] Device Examples 2-28

[0162] Device Examples 2-28 respectively provide methods for preparing organic electroluminescent devices, which are basically the same as the operations of the method for preparing the organic electroluminescent device provided in Device Example 1, except that compounds 23, 55, 153, 211, 12, 13, 14, 19, 22, 28, 35, 44, 49, 59, 64, 66, 72, 74, 89, 95, 99, 115, 128, 149, 168, 185, and 208 are respectively used to replace Compound 1 in Device Example 1 for evaporation of the light-emitting auxiliary layer.

[0163] Device Comparative Examples 1-7

[0164] Comparative Examples 1-7 each provide a method for preparing an organic electroluminescent device. The preparation methods are substantially identical to the preparation method provided in Device Example 1, with the only difference being that the organic electroluminescent devices in Comparative Examples 1-7 utilize existing comparative compounds a, b, c, d, e, f, and g, respectively, instead of Compound 1 in Device Example 1, for vapor deposition. The chemical structures of comparative compounds a, b, c, d, e, f, and g are shown below:

[0165]

[0166] Detection

[0167] The driving voltage, luminous efficiency, BI value and lifespan of the organic electroluminescent devices containing organic compounds obtained in the above-mentioned device application examples 1-28 and device comparison examples 1-7 were characterized at a brightness of 1000 (nits). The test results are shown in Table 2.

[0168] Table 2 Luminous characteristics test results (brightness value is 1000 nits)

[0169]

[0170] Note: In blue top-emitting devices, the current efficiency is greatly affected by chromaticity. Therefore, the influence of chromaticity on efficiency is taken into account, and the ratio of luminous efficiency to CIEy is defined as the BI value.

[0171] As shown in Table 2, compared with the organic electroluminescent devices provided in Comparative Examples 1-7, the organic electroluminescent devices prepared using the luminescent auxiliary materials provided by the present invention in Application Examples 1-28 have lower driving voltages and improved luminous efficiency and lifespan.

[0172] Further analysis shows that the organic compounds provided by the embodiments of the present invention, compared with existing compounds, even if they have the same parent core, can improve the hole mobility of the compound and change the spatial structure by changing the side chain and extending the molecular conjugation, thereby making it more adaptable to the device, effectively improving the lifespan and luminous efficiency of the OLED device while reducing the driving voltage.

[0173] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An organic compound, characterized in that 。 2. A luminescence auxiliary material for preparing a luminescence auxiliary layer, characterized in that: It comprises the organic compound according to claim 1.

3. An organic electroluminescent device, characterized in that: The light-emitting auxiliary layer comprises a light-emitting auxiliary layer, which is prepared by using the organic compound according to claim 1 or the light-emitting auxiliary material for preparing the light-emitting auxiliary layer according to claim 2.

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