A luminescence auxiliary material, a preparation method thereof and an application thereof

Abstract

The present invention discloses a luminescence auxiliary material, a preparation method thereof, and an application thereof, relating to the technical field of luminescent materials. The present invention provides a novel luminescence auxiliary material. By extending the molecular conjugation of the upper side chain groups of the compound, the hole mobility of the compound can be improved, and the spatial structure is changed, so that it is more adaptable to the device, and the lifetime and luminescence efficiency of the OLED device can be effectively improved while reducing the driving voltage.

Description

Technical Field

[0001] The present invention relates to the technical field of luminescent materials, and in particular, to a luminescence auxiliary material, a preparation method thereof, and an application thereof. Background Art

[0002] OLED materials are divided into luminescent materials, hole transport materials, electron transport materials, etc. Among them, hole transport materials usually have a low highest occupied molecular orbital (HOMO) value. Excitons generated in the luminescent layer diffuse to the interface of the hole transport layer or the side of the hole transport layer, ultimately resulting in luminescence at the interface of the luminescent layer or charge imbalance in the luminescent layer, thereby emitting light at the interface of the hole transport layer, reducing the color purity and efficiency of the organic electroluminescent device, and shortening the service life. By introducing a luminescence auxiliary layer between the luminescent layer and the hole transport layer, the above technical problems can be effectively avoided.

[0003] Currently, the materials used as the luminescence auxiliary layer are limited. Most of these materials adopt a fluorene ring structure. They have a high hole mobility and a high T1 energy to block the diffusion of excitons after recombination to the transport layer, improving the overall efficiency of the device. At the same time, a suitable HOMO value reduces the hole transport barrier from the transport layer to the luminescent layer, resulting in a lower driving voltage of the device and an improved service life.

[0004] So far, an organic layer material for stable and efficient organic electrical components has not been fully developed. How to develop a new luminescence auxiliary material to improve the service life and luminescence efficiency of OLED devices while reducing the driving voltage has always been an urgent problem for those skilled in the art.

[0005] In view of this, the present invention is specifically proposed. Summary of the Invention

[0006] An object of the present invention is to provide a luminescence auxiliary material and a preparation method thereof, aiming to improve the service life and luminescence efficiency of OLED devices while reducing the driving voltage by using the luminescence auxiliary material.

[0007] Another object of the present invention is to provide an organic electroluminescent device, which has the advantages of a long service life, good luminescence efficiency, and a low driving voltage.

[0008] A third object of the present invention is to improve the application of the above organic electroluminescent device in the preparation of organic light-emitting devices or organic thin-film transistors.

[0009] The present invention is implemented as follows:

[0010] In a first aspect, the present invention provides a luminescence auxiliary material, and its structural formula is shown as general formula I:

[0011]

[0012] Wherein, X represents oxygen or sulfur;

[0013] Ar is selected from any one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted 3- to 20-membered heteroaryl group, and the heteroatoms in the heteroaryl group are independently selected from oxygen, nitrogen or sulfur, and Ar is fused to the benzene ring;

[0014] L is selected from a linking bond or Wherein, R3 is selected from any one 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- to 30-membered heterocycloalkyl group, a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted 3- to 30-membered heteroaryl group, and the heteroatoms in the heterocycloalkyl group and the heteroaryl group are independently selected from oxygen, nitrogen or sulfur;

[0015] R1 and R2 are each independently selected from hydrogen, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted 3- to 30-membered heterocycloalkyl group, a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted 3- to 30-membered heteroaryl group, and the heteroatoms in the heterocycloalkyl group and the heteroaryl group are independently selected from oxygen, nitrogen or sulfur;

[0016] Ar1 and Ar2 are each independently selected from any one of a substituted or unsubstituted 3- to 30-membered heterocycloalkyl group, a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted 3- to 30-membered heteroaryl group, and the heteroatoms in the heterocycloalkyl group and the heteroaryl group are independently selected from oxygen, nitrogen or sulfur.

[0017] In a second aspect, the present invention further provides a preparation method of a light-emitting auxiliary material, and its synthetic route is as follows:

[0018]

[0019] Wherein, Hal1, Hal2 and Hal3 are each independently selected from halogens.

[0020] In a third aspect, the present invention further provides an organic electroluminescent device, including a first electrode, a second electrode and an organic layer disposed between the first electrode and the second electrode, and the organic layer contains the light-emitting auxiliary material in the above embodiments.

[0021] In a fourth aspect, the present invention further provides the application of the above organic electroluminescent device in the preparation of an organic light-emitting device or an organic thin-film transistor.

[0022] The present invention has the following beneficial effects: The present invention provides a novel light-emitting auxiliary material. By extending the molecular conjugation of the side-chain groups on the compound, the hole mobility of the compound can be improved, and the spatial structure can be changed, so that it is more suitable for the device, and the lifetime and light-emitting efficiency of the OLED device can be effectively improved while reducing the driving voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0024] Figure 1 1H NMR spectrum of the product prepared for the example. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] In order to make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Those not specified in the embodiments are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or instruments not specified by the manufacturer are all conventional products that can be obtained through commercial purchase.

[0026] The term "substituted or unsubstituted" in the present invention means being substituted by one, two, or more substituents selected from the following, such as deuterium; halogen groups; nitrile groups; hydroxyl groups; carbonyl groups; ester groups; silyl groups; boron groups; substituted or unsubstituted alkyl groups; substituted or unsubstituted cycloalkyl groups; substituted or unsubstituted alkoxy groups; substituted or unsubstituted alkenyl groups; substituted or unsubstituted alkylamino groups; substituted or unsubstituted heterocyclic amino groups; substituted or unsubstituted arylamino groups; substituted or unsubstituted aryl groups; and substituted or unsubstituted heterocyclic groups, or being substituted by substituents formed by connecting two or more of the above-mentioned substituents, or having no substituents. For example, "substituents formed by connecting two or more substituents" may include biphenyl. In other words, biphenyl can be an aryl group, or can be interpreted as a substituent formed by connecting two phenyl groups.

[0027] An embodiment of the present invention provides a light-emitting auxiliary material, and its structural formula is shown in General Formula I:

[0028]

[0029] Wherein, in General Formula I, X represents oxygen (O) or sulfur (S), and can be oxygen or sulfur.

[0030] In General Formula I, Ar is selected from any one of a substituted or unsubstituted C6-C30 aryl group and a substituted or unsubstituted 3- to 20-membered heteroaryl group, and the heteroatoms in the heteroaryl group are independently selected from oxygen (O), nitrogen (N), or sulfur (S), and Ar is fused to the benzene ring, and the fusion site can be the 1,2-position, 2,3-position, or 3,4-position. Specifically, the C6-C30 aryl group means that the number of C atoms in the aryl group is 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30; similarly, the 3- to 20-membered heteroaryl group is named according to the number of carbon atoms, and its specific meaning will not be elaborated here.

[0031] In General Formula I, L is selected from a linking bond or When L is a linking bond, the N atom is directly connected to the benzene ring.

[0032] Specifically, R3 is selected from any one 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- to 30-membered heterocycloalkyl group, a substituted or unsubstituted C6-C30 aryl group, and a substituted or unsubstituted 3- to 30-membered heteroaryl group, and the heteroatoms in the heterocycloalkyl group and the heteroaryl group are independently selected from oxygen, nitrogen, or sulfur.

[0033] In General Formula I, R1 and R2 are each independently selected from hydrogen, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted 3- to 30-membered heterocycloalkyl group, a substituted or unsubstituted C6-C30 aryl group, and a substituted or unsubstituted 3- to 30-membered heteroaryl group, and the heteroatoms in the heterocycloalkyl group and the heteroaryl group are independently selected from oxygen, nitrogen, or sulfur.

[0034] In General Formula I, Ar1 and Ar2 are each independently selected from any one of a substituted or unsubstituted 3- to 30-membered heterocycloalkyl group, a substituted or unsubstituted C6-C30 aryl group, and a substituted or unsubstituted 3- to 30-membered heteroaryl group, and the heteroatoms in the heterocycloalkyl group and the heteroaryl group are independently selected from oxygen, nitrogen, or sulfur.

[0035] It should be noted that by selecting groups such as R1, R2, Ar1, and Ar2, the molecular conjugation can be extended, the hole mobility of the compound can be increased, and the spatial structure can be changed, so that it is more adaptable on the device, and the lifetime and luminous efficiency of the OLED device can be effectively improved while reducing the driving voltage.

[0036] To further improve the lifetime and luminous efficiency of the OLED device while reducing the driving voltage, the inventors optimized the selection of each group:

[0037] In a preferred embodiment, Ar is selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthryl and phenanthryl, and Ar is fused and ring-closed with an adjacent benzene ring on the parent nucleus; the structural formula of the luminescence auxiliary material is any one of the general formulas II-1 to II-12:

[0038]

[0039] In a preferred embodiment, L is selected from any one of the following groups:

[0040]

[0041] In a preferred embodiment, each of R1 and R2 is independently selected from any one of the following groups:

[0042]

[0043] Specifically, the group selections of R1 and R2 can be the same or different, and are independently selected from the above groups.

[0044] In a preferred embodiment, each of Ar1 and Ar2 is independently selected from one or a combination of several of the following groups:

[0045]

[0046] Specifically, the group selections of Ar1 and Ar2 can be the same or different, and are independently selected from the above groups, and can be one group or a combination of several groups, which is not limited herein.

[0047] In a more preferred embodiment, the luminescence auxiliary material is selected from any one of Compounds 1-263. After the following 263 compounds are applied to the OLED device, the lifetime and luminous efficiency of the OLED device can be significantly improved, and the driving voltage can be reduced at the same time. Compounds 1-263 are specifically:

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063] An embodiment of the present invention also provides a preparation method of the above-mentioned luminescence auxiliary material, and its synthesis route is as follows:

[0064]

[0065] Specifically, the selection of R1, R2, X, L, Ar1, and Ar2 in the reaction route refers to the introduction content of the luminescence auxiliary material (general formula I), which will not be repeated here. Hal1, Hal2, and Hal3 are each independently selected from halogens, such as fluorine, chlorine, bromine, or iodine.

[0066] The specific steps of the above synthesis route are as follows:

[0067] (1) Dissolve raw material A and raw material B in toluene, add Pd2(dba)3, P(t-Bu)3, and t-BuONa under a N2 atmosphere, heat up to 105 - 115 °C and stir for 8 - 12 h. After the reaction is completed, filter while hot using diatomaceous earth to remove salts and catalysts. After the filtrate is cooled to room temperature, add distilled water to the filtrate for washing. After liquid separation, retain the organic phase, extract the aqueous phase with ethyl acetate, then dry the combined organic layer using magnesium sulfate, and remove the solvent using a rotary evaporator. Finally, use a mixture of dichloromethane and petroleum ether as the eluent, and purify the remaining substance by column chromatography to obtain the compound shown in intermediate 1.

[0068] (2) Dissolve intermediate 1 and raw material C in toluene, then add Pd2(dba)3, P(t-Bu)3 and t-BuONa under a N2 atmosphere. Heat the mixture to 105 - 115 °C and stir for 8 - 12 h. After the reaction is completed, filter while hot using diatomaceous earth to remove salts and catalysts. After the filtrate is cooled to room temperature, add distilled water to the filtrate for washing. After liquid separation, retain the organic phase, extract the aqueous phase with ethyl acetate, then dry the combined organic layers using magnesium sulfate, and remove the solvent using a rotary evaporator. Finally, purify the remaining substance by column chromatography using a mixture of dichloromethane and petroleum ether as the eluent to obtain the compound shown in intermediate 2.

[0069] (3) Under N2 protection, add intermediate 2, raw material D, tetrakis(triphenylphosphine)palladium and potassium carbonate into a mixed solvent of toluene, ethanol and water respectively. Heat the mixture to 90 - 100 °C and react for 8 - 10 h. After the reaction is completed, cool to room temperature. After the solid has precipitated completely, filter and wash with water to remove salts, then rinse with a small amount of ethanol, dry the filter cake, and recrystallize it in a methanol solution to obtain the compound shown in the above general formula 1.

[0070] The embodiment of the present invention also provides an organic electroluminescent device, which includes a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode. The organic layer contains the above-mentioned light-emitting auxiliary material. The structure of the organic layer is not limited and can be at least one layer structure.

[0071] In some embodiments, the organic layer includes a hole injection layer, a hole transport layer, a light-emitting auxiliary layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer disposed in sequence. The light-emitting auxiliary layer is prepared using the light-emitting auxiliary material. The inventors found that using the light-emitting auxiliary material provided in the embodiment of the present invention as the light-emitting auxiliary layer can significantly improve the lifespan and luminous efficiency of the OLED device, while reducing the driving voltage.

[0072] Furthermore, the above-mentioned organic electroluminescent device can be further fabricated into products such as an organic light-emitting device or an organic thin-film transistor, etc., and has broad application prospects.

[0073] The features and properties of the present invention will be further described in detail below in conjunction with the embodiments.

[0074] It should be noted that the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0075] Example 1

[0076] This embodiment provides a method for preparing a light-emitting auxiliary material, comprising the following steps:

[0077]

[0078] Dissolve raw material A (40.00 mmol) and raw material B (40.00 mmol) in toluene, then add Pd2(dba)3 (0.40 mmol), P(t-Bu)3 (2.00 mmol) and t-BuONa (80.00 mmol) under a N2 atmosphere, heat up to 115 °C and stir for reaction for 12 h. After the reaction is completed, filter while hot using diatomaceous earth to remove salts and catalysts. After the filtrate is cooled to room temperature, add distilled water to the filtrate for washing, retain the organic phase after liquid separation, extract the aqueous phase with ethyl acetate, then dry the combined organic layer using magnesium sulfate, and remove the solvent using a rotary evaporator. Finally, use a mixture of dichloromethane and petroleum ether (V:V = 1:16) as the eluent, and purify the remaining substance by column chromatography to obtain the compound shown in Intermediate 1 (10.18 g, yield: 79.26%).

[0079] Dissolve Intermediate 1 (31.67 mmol) and raw material C (31.67 mmol) in toluene, then add Pd2(dba)3 (0.31 mmol), P(t-Bu)3 (1.58 mmol) and t-BuONa (63.34 mmol) under a N2 atmosphere, heat up to 115 °C and stir for reaction for 8 h. After the reaction is completed, filter while hot using diatomaceous earth to remove salts and catalysts. After the filtrate is cooled to room temperature, add distilled water to the filtrate for washing, retain the organic phase after liquid separation, extract the aqueous phase with ethyl acetate, then dry the combined organic layer using magnesium sulfate, and remove the solvent using a rotary evaporator. Finally, use a mixture of dichloromethane and petroleum ether (V:V = 1:8) as the eluent, and purify the remaining substance by column chromatography to obtain the compound shown in Intermediate 2 (12.12 g, yield: 75.34%).

[0080] Under N2 protection, add Intermediate 2 (23.85 mmol), raw material D (26.23 mmol), tetrakis(triphenylphosphine)palladium (0.23 mmol) and potassium carbonate (47.70 mmol) to a mixed solvent of toluene, ethanol and water respectively, heat up to 100 °C and react for 10 h. After the reaction is completed, cool to room temperature. After the solid has precipitated completely, filter and wash with water to remove salts, then rinse with a small amount of ethanol, dry the filter cake, and recrystallize it in a methanol solution to obtain Compound 1; (13.22 g, yield: 80.37%, Mw: 689.86).

[0081] Detect and analyze the obtained Compound-1, and the results are as follows:

[0082] HPLC purity: >99.95%.

[0083] Mass spectrometry test: The theoretical value is 689.86; the measured value is 689.69.

[0084] Elemental analysis:

[0085] Calculated values are: C, 90.54; H, 5.11; N, 2.03; O, 2.32.

[0086] Measured values are: C, 90.16; H, 5.45; N, 2.23; O, 2.41.

[0087] The nuclear magnetic resonance spectrum of the product prepared in the example is as Figure 1 shown.

[0088] Example 2

[0089] This example provides a preparation method of a luminescence auxiliary material, including the following steps:

[0090]

[0091] Dissolve raw material A (40.00 mmol) and raw material B (40.00 mmol) in toluene, then add Pd2(dba)3 (0.40 mmol), P(t-Bu)3 (2.00 mmol) and t-BuONa (80.00 mmol) under N2 atmosphere, heat up to 115 °C and stir for reaction for 12 h. After the reaction is completed, filter while hot using diatomaceous earth to remove salts and catalysts. After the filtrate is cooled to room temperature, add distilled water to the filtrate for washing. After liquid separation, retain the organic phase, extract the aqueous phase with ethyl acetate, then dry the combined organic layer with magnesium sulfate, and remove the solvent using a rotary evaporator. Finally, use a mixture of dichloromethane and petroleum ether (V:V = 1:16) as the eluent, and purify the remaining substances by column chromatography to obtain the compound shown in Intermediate 1 (10.11 g, yield: 78.69%).

[0092] After dissolving Intermediate 1 (31.45 mmol) and Raw Material C (31.45 mmol) in toluene, Pd2(dba)3 (0.31 mmol), P(t-Bu)3 (1.57 mmol) and t-BuONa (62.90 mmol) were added under a N2 atmosphere. The temperature was raised to 115 °C and the mixture was stirred for 8 h. After the reaction was completed, diatomaceous earth was used for hot filtration to remove salts and catalysts. After the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing. After liquid separation, the organic phase was retained, the aqueous phase was extracted with ethyl acetate, and then the combined organic layer was dried over magnesium sulfate. The solvent was removed using a rotary evaporator. Finally, the remaining material was purified by column chromatography using a mixture of dichloromethane and petroleum ether (V:V = 1:8) as the eluent, to obtain the compound shown in Intermediate 2 (10.45 g, yield: 76.97%).

[0093] Under N2 protection, Intermediate 2 (24.19 mmol), Raw Material D (26.60 mmol), tetrakis(triphenylphosphine)palladium (0.24 mmol) and potassium carbonate (48.38 mmol) were respectively added to a mixed solvent of toluene, ethanol and water. The temperature was raised to 100 °C and the reaction was carried out for 10 h. After the reaction was completed, it was cooled to room temperature. After the solid had precipitated completely, filtration was carried out and the salts were removed by washing with water, followed by rinsing with a small amount of ethanol. The filter cake was dried and recrystallized in a methanol solution to obtain Compound 7; (11.82 g, yield: 79.65%, Mw: 613.76).

[0094] The obtained Compound-7 was detected and analyzed, and the results were as follows:

[0095] HPLC purity: >99.95%.

[0096] Mass spectrometry test: The theoretical value was 613.76; the measured value was 613.97.

[0097] Elemental analysis:

[0098] Calculated value: C, 90.02; H, 5.09; N, 2.28; O, 2.61.

[0099] Measured value: C, 89.88; H, 5.21; N, 2.35; O, 2.73.

[0100] Example 3

[0101] This example provides a preparation method of a luminescence auxiliary material, including the following steps:

[0102]

[0103] After dissolving raw material A (40.00 mmol) and raw material B (40.00 mmol) in toluene, Pd2(dba)3 (0.40 mmol), P(t-Bu)3 (2.00 mmol) and t-BuONa (80.00 mmol) were added under a N2 atmosphere. The temperature was raised to 115 °C and the mixture was stirred for reaction for 12 h. After the reaction was completed, diatomaceous earth was used for hot filtration to remove salts and catalysts. After the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing. After liquid separation, the organic phase was retained, the aqueous phase was extracted with ethyl acetate, then the combined organic layer was dried with magnesium sulfate, and the solvent was removed using a rotary evaporator. Finally, a mixture of dichloromethane and petroleum ether (V:V = 1:16) was used as the eluent, and the remaining substance was purified by column chromatography to obtain the compound shown in Intermediate 1 (12.35 g, yield: 77.69%).

[0104] After dissolving Intermediate 1 (31.06 mmol) and raw material C (31.06 mmol) in toluene, Pd2(dba)3 (0.31 mmol), P(t-Bu)3 (1.55 mmol) and t-BuONa (62.12 mmol) were added under a N2 atmosphere. The temperature was raised to 115 °C and the mixture was stirred for reaction for 8 h. After the reaction was completed, diatomaceous earth was used for hot filtration to remove salts and catalysts. After the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing. After liquid separation, the organic phase was retained, the aqueous phase was extracted with ethyl acetate, then the combined organic layer was dried with magnesium sulfate, and the solvent was removed using a rotary evaporator. Finally, a mixture of dichloromethane and petroleum ether (V:V = 1:8) was used as the eluent, and the remaining substance was purified by column chromatography to obtain the compound shown in Intermediate 2 (11.78 g, yield: 74.69%).

[0105] Under N2 protection, Intermediate 2 (23.18 mmol), raw material D (25.49 mmol), tetrakis(triphenylphosphine)palladium (0.23 mmol) and potassium carbonate (46.36 mmol) were respectively added to a mixed solvent of toluene, ethanol and water. The temperature was raised to 100 °C and the reaction was carried out for 10 h. After the reaction was completed, it was cooled to room temperature. After the solid had precipitated completely, filtration was carried out and the salts were removed by washing with water, then it was rinsed with a small amount of ethanol, the filter cake was dried, and it was recrystallized in a methanol solution to obtain Compound 80; (12.49 g, yield: 78.13%, Mw: 689.86).

[0106] The obtained Compound -80 was detected and analyzed, and the results were as follows:

[0107] HPLC purity: >99.95%.

[0108] Mass spectrometry test: The theoretical value was 689.86; the measured value was 689.62.

[0109] Elemental analysis:

[0110] The calculated values are: C, 90.54; H, 5.11; N, 2.03; O, 2.32.

[0111] The measured values are: C, 90.23; H, 5.41; N, 2.31; O, 2.39.

[0112] Example 4

[0113] This example provides a method for preparing a luminescence auxiliary material, which includes the following steps:

[0114]

[0115] Dissolve raw material A (40.00 mmol) and raw material B (40.00 mmol) in toluene, then add Pd2(dba)3 (0.40 mmol), P(t-Bu)3 (2.00 mmol) and t-BuONa (80.00 mmol) under N2 atmosphere, heat up to 115 °C and stir for reaction for 12 h. After the reaction is completed, filter while hot using diatomaceous earth to remove salts and catalysts. After the filtrate is cooled to room temperature, add distilled water to the filtrate for washing. After liquid separation, retain the organic phase, extract the aqueous phase with ethyl acetate, then dry the combined organic layer using magnesium sulfate, and remove the solvent using a rotary evaporator. Finally, use a mixture of dichloromethane and petroleum ether (V:V = 1:16) as the eluent, and purify the remaining substance by column chromatography to obtain the compound shown in Intermediate 1 (10.31 g, yield: 80.25%).

[0116] Dissolve Intermediate 1 (32.07 mmol) and raw material C (32.07 mmol) in toluene, then add Pd2(dba)3 (0.32 mmol), P(t-Bu)3 (1.60 mmol) and t-BuONa (64.14 mmol) under N2 atmosphere, heat up to 115 °C and stir for reaction for 8 h. After the reaction is completed, filter while hot using diatomaceous earth to remove salts and catalysts. After the filtrate is cooled to room temperature, add distilled water to the filtrate for washing. After liquid separation, retain the organic phase, extract the aqueous phase with ethyl acetate, then dry the combined organic layer using magnesium sulfate, and remove the solvent using a rotary evaporator. Finally, use a mixture of dichloromethane and petroleum ether (V:V = 1:8) as the eluent, and purify the remaining substance by column chromatography to obtain the compound shown in Intermediate 2 (12.41 g, yield: 76.19%).

[0117] Under N2 protection, intermediate 2 (24.42 mmol), raw material D (26.86 mmol), tetrakis(triphenylphosphine)palladium (0.24 mmol), and potassium carbonate (48.84 mmol) were separately added to a mixed solvent of toluene, ethanol, and water. The temperature was raised to 100 °C and the reaction was carried out for 10 h. After the reaction was completed, it was cooled to room temperature. After the solid had precipitated completely, it was filtered by suction, washed with water to remove salts, rinsed with a small amount of ethanol, the filter cake was dried, and recrystallized in a methanol solution to obtain compound 143; (13.66 g, yield: 81.16%, Mw: 689.86).

[0118] The obtained compound - 143 was detected and analyzed, and the results are as follows:

[0119] HPLC purity: > 99.95%.

[0120] Mass spectrometry test: The theoretical value was 689.86; the measured value was 689.69.

[0121] Elemental analysis:

[0122] Calculated values were: C, 90.54; H, 5.11; N, 2.03; O, 2.32.

[0123] Measured values were: C, 90.23; H, 5.32; N, 2.19; O, 2.41.

[0124] Example 5

[0125] This example provides a method for preparing a luminescence auxiliary material, which includes the following steps:

[0126]

[0127] Raw material A (40.00 mmol) and raw material B (40.00 mmol) were dissolved in toluene, and then Pd2(dba)3 (0.40 mmol), P(t - Bu)3 (2.00 mmol), and t - BuONa (80.00 mmol) were added under a N2 atmosphere. The temperature was raised to 115 °C and stirred for reaction for 12 h. After the reaction was completed, it was filtered by suction while hot using diatomaceous earth to remove salts and catalysts. After the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing. After liquid separation, the organic phase was retained, the aqueous phase was extracted with ethyl acetate, then the combined organic layer was dried using magnesium sulfate, and the solvent was removed using a rotary evaporator. Finally, a mixture of dichloromethane and petroleum ether (V:V = 1:16) was used as the eluent, and the remaining material was purified by column chromatography to obtain the compound shown in intermediate 1 (10.18 g, yield: 79.25%).

[0128] After dissolving intermediate 1 (31.67 mmol) and raw material C (31.67 mmol) in toluene, Pd2(dba)3 (0.31 mmol), P(t-Bu)3 (1.58 mmol) and t-BuONa (63.34 mmol) were added under a N2 atmosphere. The temperature was raised to 115 °C and the mixture was stirred for 8 h. After the reaction was completed, diatomaceous earth was used for hot filtration to remove salts and catalysts. After the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing. After liquid separation, the organic phase was retained, the aqueous phase was extracted with ethyl acetate, and then the combined organic layer was dried over magnesium sulfate. The solvent was removed using a rotary evaporator. Finally, the residue was purified by column chromatography using a mixture of dichloromethane and petroleum ether (V:V = 1:8) as the eluent, obtaining the compound shown in intermediate 2 (12.25 g, yield: 76.19%).

[0129] Under N2 protection, intermediate 2 (24.11 mmol), raw material D (26.52 mmol), tetrakis(triphenylphosphine)palladium (0.24 mmol) and potassium carbonate (48.22 mmol) were respectively added to a mixed solvent of toluene, ethanol and water. The temperature was raised to 100 °C and the reaction was carried out for 10 h. After the reaction was completed, it was cooled to room temperature. After the solid had precipitated completely, filtration was carried out and the salts were removed by washing with water, followed by rinsing with a small amount of ethanol. The filter cake was dried and recrystallized in a methanol solution to obtain compound 211; (14.69 g, yield: 79.61%, Mw: 765.96).

[0130] The obtained compound - 211 was detected and analyzed, and the results were as follows:

[0131] HPLC purity: > 99.95%.

[0132] Mass spectrometry test: The theoretical value was 765.96; the measured value was 766.23.

[0133] Elemental analysis:

[0134] Calculated values: C, 90.95; H, 5.13; N, 1.83; O, 2.09.

[0135] Measured values: C, 90.31; H, 5.41; N, 2.15; O, 2.31.

[0136] Example 6

[0137] This example provides a preparation method of a luminescence auxiliary material, including the following steps:

[0138]

[0139] After dissolving raw material A (40.00 mmol) and raw material B (40.00 mmol) in toluene, Pd2(dba)3 (0.40 mmol), P(t-Bu)3 (2.00 mmol) and t-BuONa (80.00 mmol) were added under a N2 atmosphere. The temperature was raised to 115 °C and the reaction was stirred for 12 h. After the reaction was completed, diatomaceous earth was used for hot filtration to remove salts and catalysts. After the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing. After liquid separation, the organic phase was retained, the aqueous phase was extracted with ethyl acetate, and then the combined organic layer was dried with magnesium sulfate. The solvent was removed using a rotary evaporator. Finally, a mixture of dichloromethane and petroleum ether (V:V = 1:16) was used as the eluent, and the remaining material was purified by column chromatography to obtain the compound shown in Intermediate 1 (10.10 g, yield: 78.67%).

[0140] After dissolving Intermediate 1 (31.42 mmol) and raw material C (31.42 mmol) in toluene, Pd2(dba)3 (0.31 mmol), P(t-Bu)3 (1.57 mmol) and t-BuONa (62.84 mmol) were added under a N2 atmosphere. The temperature was raised to 115 °C and the reaction was stirred for 8 h. After the reaction was completed, diatomaceous earth was used for hot filtration to remove salts and catalysts. After the filtrate was cooled to room temperature, distilled water was added to the filtrate for washing. After liquid separation, the organic phase was retained, the aqueous phase was extracted with ethyl acetate, and then the combined organic layer was dried with magnesium sulfate. The solvent was removed using a rotary evaporator. Finally, a mixture of dichloromethane and petroleum ether (V:V = 1:8) was used as the eluent, and the remaining material was purified by column chromatography to obtain the compound shown in Intermediate 2 (12.10 g, yield: 75.87%).

[0141] Under N2 protection, Intermediate 2 (23.81 mmol), raw material D (26.19 mmol), tetrakis(triphenylphosphine)palladium (0.23 mmol) and potassium carbonate (47.62 mmol) were respectively added to a mixed solvent of toluene, ethanol and water. The temperature was raised to 100 °C and the reaction was carried out for 10 h. After the reaction was completed, it was cooled to room temperature. After the solid had precipitated completely, it was filtered and washed with water to remove salts, and then rinsed with a small amount of ethanol. The filter cake was dried and recrystallized in a methanol solution to obtain Compound 234; (14.67 g, yield: 80.51%, Mw: 765.96).

[0142] The obtained Compound-234 was detected and analyzed, and the results are as follows:

[0143] HPLC purity: >99.95%.

[0144] Mass spectrometry test: The theoretical value was 765.96; the measured value was 765.74.

[0145] Elemental analysis:

[0146] The calculated values are: C, 90.95; H, 5.13; N, 1.83; O, 2.09.

[0147] The measured values are: C, 90.26; H, 5.37; N, 2.12; O, 2.26.

[0148] The structural formula of the compound prepared in the above examples is the general formula 1 in the invention content. The synthesis routes and principles of other compounds are the same as those of the examples listed above, so they will not be enumerated here.

[0149] The following luminescence assisting materials shown in Table 1 can be obtained according to the above preparation method:

[0150] Summary of luminescence assisting materials prepared in other examples in Table 1

[0151] Compound Molecular formula Calculated MS value Measured MS value Yield (%) Compound 9 C46H31NO 613.76 613.49 79.13 Compound 13 C46H29NO2 627.74 627.48 74.58 Compound 14 C42H27NO 561.68 561.48 76.35 Compound 18 C50H33NO 663.82 663.64 78.65 Compound 23 C54H35NO 713.88 713.69 74.21 Compound 28 C52H35NO 689.86 691.02 75.58 Compound 33 C54H35NO 713.88 714.13 76.05 Compound 40 C58H39NO 765.96 766.12 77.24 Compound 49 C58H39NO 765.96 765.74 79.33 Compound 55 C52H35NO 689.86 689.61 77.34 Compound 65 C42H27NO 561.68 561.91 80.26 Compound 68 C55H39NO2 745.92 745.68 76.59 Compound 70 C52H35NO 689.86 689.58 75.89 Compound 76 C58H39NO 765.96 765.64 70.11 Compound 84 C54H35NO 713.88 714.16 70.12 Compound 87 C56H37NO 739.92 740.24 69.35 Compound 91 C58H39NO 765.96 765.71 65.98 Compound 95 C60H39NO 789.98 789.67 70.35 Compound 106 C60H39NO 789.98 790.14 75.68 Compound 110 C52H33NO2 703.84 703.58 76.18 Compound 119 C42H27NO 561.68 561.87 81.64 Compound 126 C46H31NO 613.76 613.49 79.19 Compound 130 C58H39NO 765.96 765.68 78.47 Compound 136 C56H37NO 739.92 739.68 75.24 Compound 141 C56H37NO 739.92 740.24 66.54 Compound 146 C62H41NO 816.02 816.34 68.59 Compound 153 C52H35NO 689.86 689.73 71.33 Compound 156 C62H41NO 816.02 816.35 67.52 Compound 162 C62H41NO 816.02 715.89 78.24 Compound 165 C54H35NO 713.88 713.66 77.54 Compound 170 C62H41NO 816.02 816.3 69.14 Compound 173 C62H41NO 816.02 816.29 70.27 Compound 182 C53H34N2O 702.86 702.64 74.35 Compound 191 C62H40N2O 829.02 829.31 69.22 Compound 198 C64H41NO2 856.04 856.36 73.59 Compound 205 C52H33NOS 719.9 719.67 77.44 Compound 214 C52H35NO 689.86 689.57 68.52 Compound 218 C52H35NS 705.92 705.77 71.55 Compound 231 C55H39NO 729.92 730.18 69.67

[0152] When preparing an organic electroluminescent device using the luminescence assisting material prepared in the embodiment of the present invention, when the organic layer of the organic electroluminescent device includes a luminescence assisting layer, the luminescence assisting layer includes the luminescence assisting material provided in the above embodiment.

[0153] Device Example 1

[0154] The preparation of an organic electroluminescent device containing a luminescence assisting material specifically includes the following steps:

[0155] a. ITO anode: A glass substrate of ITO (indium tin oxide)-Ag-ITO (indium tin oxide) with a coating thickness of 150 nm is washed twice in distilled water, ultrasonically washed for 30 min, then repeatedly washed twice with distilled water, ultrasonically washed for 10 min. After the washing is completed, it is then transferred to a spin dryer for spin drying, and finally baked in a vacuum oven at 220 °C for 2 hours. After the baking is completed and cooled, it can be used. Using this substrate as the anode, a vapor deposition process for the device is carried out using a vapor deposition machine, and other functional layers are vapor deposited on it in sequence.

[0156] b. HIL (hole injection layer): At a vapor deposition rate, the hole injection layer materials HT and P-dopant are vacuum vapor deposited. Their chemical formulas are shown below; among them, the vapor deposition rate ratio of HT and P-dopant is 97:3, and the thickness is 10 nm.

[0157] c. HTL (hole transport layer): At a vapor deposition rate, 120 nm of HT is vacuum vapor deposited on the hole injection layer as the hole transport layer.

[0158] d. Luminescence assisting layer: At a The evaporation rate is used to vacuum evaporate 10 nm of Compound 1 provided in Example 1 as a light-emitting auxiliary layer on the hole transport layer.

[0159] e, EML (light-emitting layer): Then, on the above-mentioned light-emitting auxiliary layer, at the evaporation rate, a host material (Host) and a dopant material (Dopant) with a thickness of 25 nm are vacuum evaporated as the light-emitting layer. The chemical formulas of the Host and Dopant are as follows; among them, the evaporation rate ratio of the Host and Dopant is 98:2.

[0160] f, HBL (hole blocking layer): At the evaporation rate, 5.0 nm of HB is vacuum evaporated as the hole blocking layer, and its chemical formula is as follows.

[0161] g, ETL (electron transport layer): At the evaporation rate, 30 nm of ET and Liq are vacuum evaporated as the electron transport layer. The chemical formula of the ET is as follows; among them, the evaporation rate ratio of the ET and Liq is 50:50.

[0162] h, EIL (electron injection layer): At the evaporation rate, a 1.0 nm Yb film layer is evaporated to form an electron injection layer.

[0163] i, cathode: At the evaporation rate ratio, 18 nm of magnesium and silver are evaporated, and the evaporation rate ratio is 1:9 to obtain an OLED device.

[0164] j, light extraction layer: At the evaporation rate, 70 nm of CPL is vacuum evaporated on the cathode as the light extraction layer.

[0165] k, encapsulate the evaporated substrate: First, use a gluing device to coat the cleaned cover plate with UV glue, then move the coated cover plate to the lamination section, place the evaporated substrate on the upper end of the cover plate, and finally laminate the substrate and the cover plate under the action of a laminating device, while completing the photo-curing of the UV glue.

[0166] The structural formulas involved in the preparation process are as follows:

[0167]

[0168] Referring to the method provided in Device Example 1 above, Compounds 7, 80, 143, 9, 13, 14, 18, 23, 28, 33, 40, 49, 55, 65, 68, 70, 76, 84, 87, 91, 95, 106, 110, 119, 126, 130, 136, 141, 146, 153, 156, 162, 165, 170, 173, 182, 191, 198, 205, 211, 214, 218, 231, 234 were respectively selected to replace Compound 1, and the evaporation of the light-emitting auxiliary layer was carried out, and the corresponding organic electroluminescent devices were prepared, which were respectively denoted as Device Examples 2-45.

[0169] Device Comparative Examples 1-6:

[0170] This comparative example provides an organic electroluminescent device. The only difference between the preparation method of this organic electroluminescent device and that of Device Example 1 is that in this organic electroluminescent device, the existing comparative compounds a, b, c, d, e, f were respectively used to replace the light-emitting auxiliary material (Compound 1) in the above Device Example 1 for evaporation to prepare Device Comparative Examples 1-6. Among them, the chemical structural formulas of the comparative compounds a, b, c, d, e, f are:

[0171]

[0172] The driving voltage, luminous efficiency, BI value and lifetime of the organic electroluminescent devices containing the light-emitting auxiliary material obtained from the above Device Application Examples 1-45 and Device Comparative Examples 1-6 were characterized at a brightness of 1000 (nits). The test results are shown in Table 2. Note: In the blue top-emitting device, the current efficiency is greatly affected by chromaticity. Therefore, considering the influence factor of chromaticity on efficiency, the ratio of luminous efficiency to CIEy is defined as the BI value, that is, BI = (cd / A) / CIEy.

[0173] Table 2 Test Results of Luminescence Characteristics (Brightness Value is 1000 nits)

[0174]

[0175]

[0176]

[0177] Note: In the blue top-emitting device, the current efficiency is greatly affected by chromaticity. Therefore, considering the influence factor of chromaticity on efficiency, the ratio of luminous efficiency to CIEy is defined as the BI value, that is, BI = (cd / A) / CIEy.

[0178] As can be seen from Table 2, compared with the existing organic electroluminescent devices provided in Comparative Examples 1-6, the application examples 1-45 of the organic electroluminescent devices prepared using the light-emitting auxiliary material provided by the present invention have improved performance in terms of driving voltage, luminous efficiency, BI, and lifespan.

[0179] This indicates that: compared with the comparative compound, even if they have the same parent nucleus, by changing the side chain and extending the molecular conjugation, the hole mobility of the compound can be increased, and the spatial structure can be changed, making it more adaptable to the device. This can effectively improve the lifespan and luminous efficiency of the OLED device while reducing the driving voltage.

[0180] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and reference can be made to the description in the method part for relevant parts.

[0181] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A luminescence auxiliary material, characterized in that, Its structural formula is shown in General Formula I: The luminescence assisting material is selected from any one of the following compounds:

2. A preparation method of the luminescence assisting material according to claim 1, characterized in that, The synthetic route thereof is as follows: Wherein, Hal1, Hal2 and Hal3 are each independently selected from halogens.

3. An organic electroluminescent device, characterized in that, It includes a first electrode, a second electrode and an organic layer disposed between the first electrode and the second electrode, and the organic layer contains the luminescence assisting material described in claim 1.

4. The organic electroluminescent device according to claim 3, characterized in that, The organic layer includes a hole injection layer, a hole transport layer, a luminescence assisting layer, a light-emitting layer, a hole blocking layer, an electron transport layer and an electron injection layer which are sequentially disposed, and the luminescence assisting layer is prepared by using the luminescence assisting material.

5. Application of the organic electroluminescent device according to claim 4 in the preparation of an organic light-emitting device or an organic thin-film transistor.

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