Polycyclic aromatic organic electroluminescent material, preparation method and organic electroluminescent device containing polycyclic aromatic organic electroluminescent material

Abstract

The invention belongs to the field of organic electroluminescent materials, and discloses a polycyclic aromatic organic electroluminescent material, a preparation method and an organic electroluminescent device containing the polycyclic aromatic organic electroluminescent material. The structure of the polycyclic aromatic organic electroluminescent material is as shown in a general formula I: # imgabs0. The polycyclic aromatic organic electroluminescent material provided by the invention has the excellent characteristics of low driving voltage, high luminous efficiency and long service life after being applied to an organic electroluminescent device.

Description

Technical Field

[0001] The invention belongs to the field of organic electroluminescent materials, and in particular relates to a polycyclic aromatic organic electroluminescent material, a preparation method and an organic electroluminescent device containing the same. Background Art

[0002] Organic light emitting diode (OLED) is a new and promising display technology that has gradually entered people's field of vision. It has the advantages of active light emission without backlight, high luminous efficiency, large viewing angle, fast response speed, low energy consumption, lighter and thinner, flexible display, etc. At present, OLED display technology has been widely used in smart phones, tablet computers and other fields.

[0003] OLED is an electroluminescent device formed by a multi-layer organic thin film structure. A reasonable device structure can effectively improve the performance of the device. Specifically, in addition to the light-emitting layer, various auxiliary functional layers also play a vital role in the performance of the device. The hole transport regions such as the electron injection layer, electron transport layer, hole blocking layer, hole transport layer and hole injection layer are widely used to improve the performance of the device. Among them, the hole transport layer has the function of changing the hole transport efficiency, luminous efficiency and life of the hole to the light-emitting layer.

[0004] Although the hole transport materials currently used can improve the hole transport efficiency, luminous efficiency, device stability, etc., their service life still needs to be improved. Therefore, it is necessary to develop a hole transport material with a new structure to improve the shortcomings of the organic electroluminescent element in service life, which has become an urgent problem to be solved by those skilled in the art. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention discloses a polycyclic aromatic organic electroluminescent material, a preparation method and an organic electroluminescent device containing the same. The polycyclic aromatic organic electroluminescent material provided by the present invention is applied to an organic electroluminescent device, which has the excellent characteristics of low driving voltage, high luminous efficiency and long service life.

[0006] In order to achieve the above objectives, the first objective of the present invention is to provide a polycyclic aromatic organic electroluminescent material. The following technical scheme is adopted:

[0007] A polycyclic aromatic organic electroluminescent material, the structure of which is shown in general formula I:

[0008]

[0009] In formula Ⅰ;

[0010] X is selected from O, S, CR2R3;

[0011] R1, R2, and R3 are independently selected from substituted or unsubstituted C1-C15 alkyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C6-C30 heteroaryl, and the heteroatom thereof contains at least one of O, S, N, Si, and Se;

[0012] Ar1 and Ar2 are independently selected from substituted or unsubstituted C6-C30 aryl groups, substituted or unsubstituted C6-C30 heteroaryl groups, and their heteroatoms contain at least one of O, S, N, Si, and Se;

[0013] L is selected from a single bond, a substituted or unsubstituted C6-C12 aryl group.

[0014] Optionally, Formula I has structures I-1 to I-3:

[0015]

[0016] Furthermore, R1, R2, and R3 are independently selected from substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C6-C15 aryl, and substituted or unsubstituted C6-C15 heteroaryl, and the heteroatom thereof contains at least one of O, S, N, Si, and Se;

[0017] Ar1 and Ar2 are independently selected from substituted or unsubstituted C6-C24 aryl groups, substituted or unsubstituted C6-C15 heteroaryl groups, and their heteroatoms contain at least one of O, S, N, Si, and Se;

[0018] L1 is independently selected from a single bond, a substituted or unsubstituted phenyl group.

[0019] Furthermore, the groups connected at any position of Ar1 and Ar2 are as follows;

[0020]

[0021] The hydrogen on the above substituents is independently partially or completely replaced by deuterium; * indicates the position where the group is connected.

[0022] It should be noted that the number of carbon atoms in the alkyl, aryl and heteroaryl groups in the terms “substituted or unsubstituted C1-C15 alkyl”, “substituted or unsubstituted C1-C6 alkyl”, “substituted or unsubstituted C6-C30 aryl”, “substituted or unsubstituted C6-C24 aryl”, “substituted or unsubstituted C6-C15 aryl”, “substituted or unsubstituted C6-C12 aryl”, “substituted or unsubstituted C6-C30 heteroaryl” and “substituted or unsubstituted C6-C15 heteroaryl” means the number of carbon atoms constituting the unsubstituted alkyl, unsubstituted aryl and unsubstituted heteroaryl groups or the total number of heteroatoms and carbon atoms constituting the heteroaryl groups, without taking into account the number of carbon atoms in the substituents.

[0023] Furthermore, the term "substituted" means substituted by one, two or more substituents selected from the group consisting of hydrogen, deuterium, a halogen group, a cyano group, a trifluoromethyl group, a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a butyl group, a n-butyl group, an isobutyl group, a tert-butyl group, a sec-butyl group, a 1-methylbutyl group, a 1-ethylbutyl group, a pentyl group, a n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a hexyl group, a n-hexyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 4-methyl-2-pentyl group, a 3,3-dimethylbutyl group, a 2-ethylbutyl group, a 1-methylhexyl group, a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a thienyl group, a furanyl group, a pyrrolyl group, a benzothienyl group, a benzofuranyl group, a pyridyl group, an indolyl group, a cyclopentanyl group, a cyclohexanyl group, and an adamantane group, or substituted by two or more of the substituents shown above connected to each other, or having no substituent.

[0024] In the above technical solution, the polycyclic aromatic organic electroluminescent material is selected from any one of the following compounds:

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036] The second object of the present invention is to provide a method for preparing the polycyclic aromatic organic electroluminescent material as described above.

[0037] The compounds of the present invention can be prepared by synthetic methods known to those skilled in the art, or preferably by the following reaction schemes.

[0038]

[0039] In the above formula, X, R1, R2, R3, Ar1, Ar2, L are as defined in the above chemical formula I; X1 is selected from halogen (e.g., F, Cl, Br or I);

[0040] Step 1 specifically includes the following steps:

[0041] Under a nitrogen environment, raw material A and raw material B are added to a mixed solution of toluene, ethanol and water, followed by adding potassium carbonate and tetrakis(triphenylphosphine)palladium, stirring evenly, heating to 70°C-90°C, and reflux reaction for 4-12h, detecting the reaction by thin layer chromatography, cooling after the reaction, filtering with diatomaceous earth to remove salt and catalyst, cooling the filtrate to room temperature, washing three times with water, retaining the organic phase, and then extracting the aqueous phase with dichloromethane; combining the organic phases and concentrating, using a mixed solution of dichloromethane and petroleum ether as an eluent, and purifying by column chromatography to obtain intermediate 1;

[0042] Step 2 specifically includes the following steps:

[0043] Cool down to -70°C to -80°C to dissolve intermediate 1 in THF, slowly add n-butyl lithium to the solution of intermediate 1, react for 2-4 hours, slowly add the solution of raw material C to the reaction bottle, warm to room temperature, continue to react for 4-12 hours, detect the reaction by thin layer chromatography, wash three times with water after the reaction, retain the organic phase, then extract the aqueous phase with dichloromethane, combine the organic phases and concentrate, use a mixed solution of dichloromethane and petroleum as an eluent, and purify by column chromatography to obtain intermediate 2;

[0044] Step 3 specifically includes the following steps:

[0045] The intermediate 2 was dissolved in DCM, stirred and dissolved at room temperature, and then methanesulfonic acid was added thereto, and the mixture was reacted at room temperature for 2-4 hours. The reaction was detected by thin layer chromatography. After the reaction was completed, the mixture was washed with water three times, and the organic phase was retained. The aqueous phase was then extracted with ethyl acetate. After the organic phases were combined, they were dried with anhydrous magnesium sulfate, and the solvent was removed with a rotary evaporator. The solid organic matter was completely dissolved with dichloromethane, and then slowly added dropwise to the petroleum ether solution, stirred evenly, and a precipitate was precipitated. The solid was filtered to obtain the solid, and then washed with anhydrous ethanol and petroleum ether in turn, and dried to obtain the intermediate 3.

[0046] Step 4 specifically includes the following steps:

[0047] Under a nitrogen environment, the intermediate 3 is dissolved in a mixed solution of toluene, ethanol and water, and the raw material D is dissolved in a mixed solution of toluene, ethanol and water. The raw material D solution is slowly added to the intermediate 3 solution, potassium carbonate and tetrakis(triphenylphosphine)palladium are added thereto, and the mixture is stirred evenly. The mixture is heated to 70° C.-90° C. and refluxed for 4-12 hours. The reaction is detected by thin layer chromatography. After the reaction is completed, the mixture is cooled and filtered using diatomaceous earth to remove salt and catalyst. After the filtrate is cooled to room temperature, the mixture is washed with water three times, and the organic phase is retained. The aqueous phase is then extracted with dichloromethane; the organic phases are combined and concentrated, and a mixed solution of dichloromethane and petroleum ether is used as an eluent, and the mixture is purified by column chromatography to obtain the intermediate 4;

[0048] Step 5 specifically includes the following steps:

[0049] Under nitrogen environment, intermediate 4 is dissolved in toluene, raw material E is dissolved in toluene, and then raw material E is slowly added to the intermediate 4 solution, tri(dibenzylideneacetone)dipalladium, tri-tert-butylphosphine and sodium tert-butyl alcohol are added thereto, the temperature is raised to 100°C-120°C, and the reaction is carried out for 4-10 hours. After the reaction is completed, the temperature is lowered, and diatomaceous earth is used for filtering to remove salt and catalyst. After the filtrate is cooled to room temperature, it is washed three times with water, and the organic phase is retained, and then the aqueous phase is extracted with ethyl acetate; after the organic phases are combined, they are dried with anhydrous magnesium sulfate, and the solvent is removed with a rotary evaporator, and dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake is rinsed with petroleum ether for multiple times, and placed in a 60°C oven for drying for 5 hours to obtain chemical formula I.

[0050] The third object of the present invention is to provide an organic electroluminescent device, which comprises the polycyclic aromatic organic electroluminescent material.

[0051] Specifically, the organic electroluminescent device comprises an anode, a cathode and at least one organic thin film layer arranged between the anode and the cathode; the organic thin film layer comprises the polycyclic aromatic organic electroluminescent material as described above.

[0052] Moreover, the organic thin film layer includes a light-emitting layer, which includes a main material and a doping material; the organic thin film layer also includes at least one of a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, an electron transport layer or an electron injection layer; the hole transport layer material contains the polycyclic aromatic organic electroluminescent material as described above.

[0053] Compared with the prior art, the present invention provides a polycyclic aromatic organic electroluminescent material, a preparation method and an organic electroluminescent device containing the same, which have the following excellent effects:

[0054] The polycyclic aromatic compounds disclosed in the present invention are prepared by introducing triarylamine on the basis of the parent core. When all the triarylamine groups are substituted with aromatic groups, the energy level is low, the localization of carrier migration is avoided, and the hole transport energy barrier can be reduced, thereby increasing the migration rate and the luminous efficiency. The triarylamine has excellent hole transport performance. The triarylamine material is used as a hole transport layer, and a group with a high triplet energy level is introduced, which can reduce the energy difference between energy levels and greatly improve the life of the device. The device life and efficiency prepared by the hole transport material in the present invention are significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0056] Figure 1 is the H NMR spectrum of compound 13.

[0057] Figure 2 This is the H NMR spectrum of compound 184. DETAILED DESCRIPTION

[0058] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention and the related drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] The invention specifically discloses a polycyclic aromatic organic electroluminescent material, a preparation method and an organic electroluminescent device containing the same.

[0060] A series of palladium-catalyzed coupling reactions carried out in the present invention utilize the difference that the activity of Br is greater than that of Cl on the one hand, and on the other hand, the reaction site is controlled by controlling the reaction conditions, and the reaction is purified by column chromatography or silica gel funnel to remove by-products to obtain the target compound.

[0061] Reference to common knowledge is as follows:

[0062] "Transition Metal Organic Chemistry" (Original Sixth Edition), Robert H. Crabtree, Publisher: Shanghai East China University of Science and Technology Press, Publication Date: 2017-09-00, ISBN: 978-7-5628-5111-0, page 388.

[0063] "Organic Chemistry and Optoelectronic Materials Experimental Tutorial", Chen Runfeng, Publisher: Southeast University Press, Publication Date: 2019-11-00, ISBN: 9787564184230, Page 174.

[0064] The specific embodiments described below are only part of the embodiments of the present application, rather than all the embodiments.

[0065] In addition, it should be noted that the numerical values ​​given in the following examples are as accurate as possible, but those skilled in the art understand that due to unavoidable measurement errors and experimental operation problems, each number should be understood as an approximate number rather than an absolutely accurate value.

[0066] The features and performance of the present invention will be further described in detail below with reference to the embodiments.

[0067] Example 1

[0068]

[0069] The synthesis steps of raw material A-13 are as follows;

[0070]

[0071] Under a nitrogen environment, raw material a-13 (1.0 eq) (CAS No.: 153798-98-2) and raw material b-13 (1.5 eq) (CAS No.: 13922-41-3) are added to a mixed solution of toluene, ethanol and water, potassium carbonate (2.2 eq) and tetrakis(triphenylphosphine)palladium (0.01 eq) are added thereto, stirred evenly, heated to 85°C, and refluxed for 4 hours. After the reaction is completed, the temperature is lowered, diatomaceous earth is used for filtration to remove salt and catalyst, and the filtrate is cooled to room temperature and washed with water three times, the organic phase is retained, and the aqueous phase is extracted with dichloromethane; the organic phases are combined and concentrated, and a mixed solution of dichloromethane and petroleum ether is used as an eluent, and the raw material A-13 is purified by column chromatography;

[0072] Step 1 specifically includes the following steps:

[0073] Under nitrogen environment, raw material A-13 (1.0 eq) and raw material B-13 (1.0 eq) (CAS No.: 1451393-45-5) were added to a mixed solution of toluene, ethanol and water, potassium carbonate (2.2 eq) and tetrakis(triphenylphosphine)palladium (0.01 eq) were added thereto, stirred evenly, heated to 80°C, and refluxed for 4 hours, and the reaction was detected by thin layer chromatography. After the reaction was completed, the temperature was lowered, and diatomaceous earth was used for filtration to remove salt and catalyst. After the filtrate was cooled to room temperature, it was washed with water three times, the organic phase was retained, and then the aqueous phase was extracted with dichloromethane; the organic phases were combined and concentrated, and a mixed solution of dichloromethane and petroleum ether was used as an eluent, and intermediate 1 was purified by column chromatography (yield 72.3%);

[0074] Step 2 specifically includes the following steps:

[0075] The temperature was lowered to -78°C to dissolve the intermediate 1 (1.3 eq) in THF, ventilated 3 times, stirred for 10 minutes, and n-butyl lithium (1.2 eq) was slowly added to the solution of the intermediate 1 (1.3 eq). After reacting for 2 hours, the solution of the raw material C-13 (1.0 eq) (CAS No.: 240821-79-8) was slowly added to the reaction bottle, warmed to room temperature, and continued to react for 8 hours. The reaction was detected by thin layer chromatography. After the reaction was completed, it was washed with water three times, and the organic phase was retained. Then, the aqueous phase was extracted with dichloromethane, the organic phases were combined and concentrated, and a mixed solution of dichloromethane and petroleum was used as an eluent. Purification by column chromatography gave the intermediate 2 (yield 42.9%).

[0076] Step 3 specifically includes the following steps:

[0077] The intermediate 2 (1.0 eq) was dissolved in DCM, stirred and dissolved at room temperature, and then methanesulfonic acid (3.0 eq) was added thereto, and the reaction was carried out at room temperature for 4 h. The reaction was detected by thin layer chromatography. After the reaction was completed, the mixture was washed with water three times, and the organic phase was retained. The aqueous phase was then extracted with ethyl acetate. After the organic phases were combined, they were dried with anhydrous magnesium sulfate, and the solvent was removed with a rotary evaporator. The solid organic matter was completely dissolved with dichloromethane, and then slowly added dropwise to the petroleum ether solution, stirred evenly, and a precipitate was precipitated. The solid was filtered to obtain the solid, and then washed with anhydrous ethanol and petroleum ether in turn, and dried to obtain the intermediate 3 (yield 86.1%).

[0078] Step 4 specifically includes the following steps:

[0079] Under nitrogen environment, intermediate 3 (1.0 eq) was dissolved in toluene, and raw material D-13 (1.0 eq) (CAS No.: 1309601-64-6) was dissolved in toluene. Then, raw material D-13 (1.0 eq) (CAS No.: 1309601-64-6) was slowly added to the solution of intermediate 3 (1.0 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), tri-tert-butylphosphine (0.05 eq) and sodium tert-butyl alcohol (2.0 eq) were added thereto, and the temperature was raised to 110°C, and the reaction was carried out for 4 hours. After the reaction is completed, the temperature is lowered, and diatomaceous earth is used for filtration to remove salt and catalyst. After the filtrate is cooled to room temperature, it is washed with water three times, and the organic phase is retained. The aqueous phase is then extracted with ethyl acetate. After the organic phases are combined, they are dried with anhydrous magnesium sulfate, and the solvent is removed with a rotary evaporator and dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake is rinsed with petroleum ether several times and dried in a 60°C oven for 5 hours to obtain compound 13; (yield: 85.4%, MS (ESI, m / Z): [M+H]+=803.48).

[0080] The obtained compound 13 was tested and analyzed, and the results were as follows:

[0081] HPLC purity: >99.95%.

[0082] Elemental Analysis:

[0083] The test values ​​are: C, 90.97; H, 5.25; N, 1.83; O, 2.07.

[0084] Example 2

[0085]

[0086] The synthesis steps of raw material A-184 are as follows;

[0087]

[0088] Under nitrogen environment, raw material a-184 (1.0 eq) (CAS No.: 1423-62-7) and raw material b-184 (1.5 eq) (CAS No.: 13922-41-3) are added to a mixed solution of toluene, ethanol and water, potassium carbonate (2.2 eq) and tetrakis(triphenylphosphine)palladium (0.01 eq) are added thereto, stirred evenly, heated to 85°C, and refluxed for 4 hours. After the reaction is completed, the temperature is lowered, diatomaceous earth is used for filtering to remove salt and catalyst, and the filtrate is cooled to room temperature and washed with water three times, the organic phase is retained, and then the aqueous phase is extracted with dichloromethane; the organic phases are combined and concentrated, and a mixed solution of dichloromethane and petroleum ether is used as an eluent, and the raw material A-184 is purified by column chromatography;

[0089] Step 1 specifically includes the following steps:

[0090] Under nitrogen environment, raw material A-184 (1.0 eq) and raw material B-184 (1.0 eq) (CAS No.: 1107580-65-3) were added to a mixed solution of toluene, ethanol and water, potassium carbonate (2.2 eq) and tetrakis(triphenylphosphine)palladium (0.01 eq) were added thereto, stirred evenly, heated to 85°C, and refluxed for 5 hours, and the reaction was detected by thin layer chromatography. After the reaction was completed, the temperature was lowered, and diatomaceous earth was used for filtration to remove salt and catalyst. After the filtrate was cooled to room temperature, it was washed three times with water, the organic phase was retained, and then the aqueous phase was extracted with dichloromethane; the organic phases were combined and concentrated, and a mixed solution of dichloromethane and petroleum ether was used as an eluent, and intermediate 1 was purified by column chromatography (yield 86.4%);

[0091] Step 2 specifically includes the following steps:

[0092] The temperature was lowered to -78°C and the intermediate 1 (1.0 eq) was dissolved in THF, ventilated 3 times, stirred for 10 minutes, and n-butyl lithium (1.2 eq) was slowly added to the solution of the intermediate 1 (1.0 eq). After reacting for 2 hours, the raw material C-184 (1.0 eq) (CAS No.: 240821-79-8) solution was slowly added to the reaction bottle, warmed to room temperature, and continued to react for 8 hours. The reaction was detected by thin layer chromatography. After the reaction was completed, it was washed with water three times, and the organic phase was retained. Then, the aqueous phase was extracted with dichloromethane, the organic phases were combined and concentrated, and a mixed solution of dichloromethane and petroleum was used as an eluent. Purification by column chromatography gave the intermediate 2 (yield 75.1%);

[0093] Step 3 specifically includes the following steps:

[0094] The intermediate 2 (1.0 eq) was dissolved in DCM, stirred and dissolved at room temperature, and then methanesulfonic acid (3.0 eq) was added thereto, and the reaction was carried out at room temperature for 4 h. The reaction was detected by thin layer chromatography. After the reaction was completed, the mixture was washed with water three times, and the organic phase was retained. The aqueous phase was then extracted with ethyl acetate. After the organic phases were combined, they were dried with anhydrous magnesium sulfate, and the solvent was removed with a rotary evaporator. The solid organic matter was completely dissolved with dichloromethane, and then slowly added dropwise to the petroleum ether solution, stirred evenly, and a precipitate was precipitated. The solid was filtered to obtain the solid, and then washed with anhydrous ethanol and petroleum ether in turn, and dried to obtain the intermediate 3 (yield 91.9%).

[0095] Step 4 specifically includes the following steps:

[0096] Under nitrogen environment, intermediate 3 (1.0 eq) was dissolved in a mixed solution of toluene, ethanol and water, and raw material D-184 (1.0 eq) (CAS No.: 63503-60-6) was dissolved in a mixed solution of toluene, ethanol and water. The raw material D-184 (1.0 eq) (CAS No.: 63503-60-6) solution was slowly added to the intermediate 3 (1.0 eq) solution, potassium carbonate (2.2 eq) and tetrakis(triphenylphosphine)palladium (0.01 eq) were added thereto, stirred evenly, heated to 85° C., and refluxed for 8 h. The reaction was detected by thin layer chromatography. After the reaction was completed, the temperature was lowered, and diatomaceous earth was used for filtration to remove salt and catalyst. After the filtrate was cooled to room temperature, it was washed with water three times, the organic phase was retained, and then the aqueous phase was extracted with dichloromethane; the organic phases were combined and concentrated, and a mixed solution of dichloromethane and petroleum ether was used as an eluent, and intermediate 4 was purified by column chromatography (yield 87.2%);

[0097] Step 5 specifically includes the following steps:

[0098] Under nitrogen environment, intermediate 4 (1.0 eq) was dissolved in toluene, raw material E-103 (1.0 eq) (CAS No.: 1309601-64-6) was dissolved in toluene, and then raw material E-184 (1.0 eq) (CAS No.: 1309601-64-6) was slowly added to the intermediate 4 (1.0 eq) solution, tri(dibenzylideneacetone)dipalladium (0.01 eq), tri-tert-butylphosphine (0.05 eq) and sodium tert-butyl alcohol (2.0 eq) were added thereto, and the temperature was raised to 110°C and the reaction was carried out for 4 hours. After the reaction, the temperature was lowered, and the product was filtered using diatomaceous earth to remove salt and catalyst. After the filtrate was cooled to room temperature, it was washed with water three times, and the organic phase was retained. The aqueous phase was then extracted with ethyl acetate. After the organic phases were combined, they were dried using anhydrous magnesium sulfate, and the solvent was removed using a rotary evaporator and dissolved in petroleum ether / ethanol. The product was recrystallized and filtered. The filter cake was rinsed with petroleum ether several times and dried in an oven at 60°C for 5 hours to obtain compound 184 (yield: 84.2%, MS (ESI, m / Z): [M+H]+=895.47).

[0099] The obtained compound 184 was tested and analyzed, and the results were as follows:

[0100] HPLC purity: >99.95%.

[0101] Elemental Analysis:

[0102] The test values ​​are: C, 89.62; H, 5.15; N, 1.67; S, 3.67.

[0103] The following compounds were synthesized by referring to the methods of Examples 1 to 2 and tested using a Waters XEVO TQD mass spectrometer, which has low precision. The ESI source was used for testing, and the mass spectrometry test values ​​are shown in Table 1 below.

[0104] Table 1

[0105]

[0106]

[0107] Device Example 1: Manufacturing an organic electroluminescent device containing compound 3, specifically comprising the following steps:

[0108] 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, and then repeatedly wash it with distilled water twice, ultrasonically wash for 10 minutes. After washing, transfer it to a spin dryer for drying, and 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, use an evaporation machine to carry out the evaporation device process, and evaporate other functional layers on it in sequence.

[0109] b. HIL (hole injection layer): The vacuum evaporation deposition rate of the compound 3 provided in the above embodiment is HT-1 and P-dopant as hole injection layer materials, the evaporation rate ratio of HT-1 and P-dopant is 98:2, and the thickness is 10 nm;

[0110] c. HTL (hole transport layer): At a deposition rate of , 130 nm of the compound 3 provided in the above embodiment is vacuum-deposited on the hole injection layer as a hole transport layer;

[0111] d. Light-emitting auxiliary layer: At a deposition rate of 10 nm, EB-1 was vacuum-deposited on the hole transport layer as a light-emitting auxiliary layer.

[0112] e. EML (luminescent layer): The host material (Host) and the dopant material (Dopant) with a thickness of 20nm are vacuum evaporated on the light-emitting auxiliary layer as the light-emitting layer, wherein the evaporation rate ratio of Host to Dopant is 97:3.

[0113] f. HBL (hole blocking layer): At a deposition rate of , 5 nm of HB-1 was vacuum-deposited on the light-emitting layer as a hole blocking layer;

[0114] g. ETL (Electron Transport Layer): At a deposition rate of , 30 nm of ET-1 was vacuum-deposited on the hole blocking layer as an electron transport layer;

[0115] h. EIL (electron injection layer): At a deposition rate of , a 1.0 nm Yb film layer is vacuum-deposited on the electron transport layer to form an electron injection layer;

[0116] i. Cathode: 18 nm magnesium and silver are vacuum evaporated on the electron injection layer at a deposition rate ratio of 1:9 to obtain a cathode;

[0117] j. Light extraction layer: At a deposition rate of , CPL-1 with a thickness of 70 nm was vacuum-deposited on the cathode as a light extraction layer.

[0118] 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.

[0119] The required material structure is as follows:

[0120]

[0121] Device Example 2-Device Example 45 refers to the above method, and the compound 3 used in Device Example 1 is replaced by compounds 7, 9, 13, 14, 20, 25, 29, 33, 41, 48, 53, 59, 65, 73, 83, 90, 96, 100, 108, 115, 124, 130, 135, 143, 151, 159, 167, 175, 180, 184, 187, 192, 201, 210, 218, 229, 231, 240, 245, 251, 258, 266, 276 and 288 as hole transport layers to prepare corresponding organic electroluminescent devices.

[0122] Device Comparative Example 1 to Device Comparative Example 3:

[0123] The only difference between the preparation method of the organic electroluminescent device provided in the device comparative example and the device example 1 is that the organic electroluminescent device uses existing compounds a, b, and c to replace the hole transport material in the device example 1 for evaporation to prepare device comparative examples 1 to device comparative examples 3. The chemical structural formulas of compounds a, b, and c are as follows:

[0124]

[0125] The driving voltage, luminous efficiency, BI value and lifespan of the organic electroluminescent devices obtained from the above device embodiments 1 to 45 and device comparative examples 1 to 3 were characterized at a brightness of 1000 (nits). The test results are shown in Table 2 below.

[0126] Table 2

[0127]

[0128]

[0129] According to the above table, the organic electroluminescent device prepared by using the compound provided by the present invention as the hole transport material has a slightly lower driving voltage, an improved luminous efficiency, and a lifespan of 50-80 hours compared with the organic electroluminescent device prepared by using compounds a, b, and c as the hole transport material.

[0130] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A polycyclic aromatic organic electroluminescent material, characterized in that: The structure of the polycyclic aromatic organic electroluminescent material is shown in general formula I: In formula Ⅰ; X is selected from O, S, CR2R3; R1, R2, and R3 are independently selected from substituted or unsubstituted C1-C15 alkyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C6-C30 heteroaryl, and the heteroatom thereof contains at least one of O, S, N, Si, and Se; Ar1 and Ar2 are independently selected from substituted or unsubstituted C6-C30 aryl groups, substituted or unsubstituted C6-C30 heteroaryl groups, and their heteroatoms contain at least one of O, S, N, Si, and Se; L is selected from a single bond, a substituted or unsubstituted C6-C12 aryl group.

2. The polycyclic aromatic organic electroluminescent material according to claim 1, characterized in that: Formula I has structures I-1 to I-3:

3. The polycyclic aromatic organic electroluminescent material according to claim 1 or 2, characterized in that: R1, R2, and R3 are independently selected from substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C6-C15 aryl, and substituted or unsubstituted C6-C15 heteroaryl, and the heteroatom thereof contains at least one of O, S, N, Si, and Se; Ar1 and Ar2 are independently selected from substituted or unsubstituted C6-C24 aryl groups, substituted or unsubstituted C6-C15 heteroaryl groups, and their heteroatoms contain at least one of O, S, N, Si, and Se; L1 is independently selected from a single bond, a substituted or unsubstituted phenyl group.

4. The polycyclic aromatic organic electroluminescent material according to claim 3, characterized in that: The groups connected at any position of Ar1 and Ar2 are as follows; The hydrogen on the substituent is independently partially or completely replaced by deuterium; * indicates the position where the group is attached.

5. The polycyclic aromatic organic electroluminescent material according to claim 1, characterized in that: The structure of the polycyclic aromatic organic electroluminescent material includes but is not limited to any one of the following compounds:

6. A method for preparing a polycyclic aromatic organic electroluminescent material as claimed in claim 1, characterized in that: The method operates as follows: Step 1: Under a nitrogen environment, raw material A and raw material B are added to a mixed solution of toluene, ethanol and water, followed by adding potassium carbonate and tetrakis(triphenylphosphine)palladium, stirring evenly, heating to 70°C-90°C, and reflux reaction for 4-12h, detecting the reaction by thin layer chromatography, cooling after the reaction, filtering with diatomaceous earth to remove salt and catalyst, cooling the filtrate to room temperature, washing three times with water, retaining the organic phase, and then extracting the aqueous phase with dichloromethane; combining the organic phases and concentrating, using a mixed solution of dichloromethane and petroleum ether as an eluent, and purifying by column chromatography to obtain intermediate 1; Step 2: Cool down to -70°C to -80°C to dissolve intermediate 1 in THF, slowly add n-butyl lithium to the solution of intermediate 1, react for 2-4 hours, slowly add the solution of raw material C to the reaction bottle, warm to room temperature, continue to react for 4-12 hours, detect the reaction by thin layer chromatography, wash three times with water after the reaction, retain the organic phase, then extract the aqueous phase with dichloromethane, combine the organic phases and concentrate, use a mixed solution of dichloromethane and petroleum as an eluent, and purify by column chromatography to obtain intermediate 2; Step 3: The intermediate 2 was dissolved in DCM and stirred at room temperature to dissolve, and then methanesulfonic acid was added thereto, and the mixture was reacted at room temperature for 2-4 hours. The reaction was detected by thin layer chromatography. After the reaction was completed, the mixture was washed with water three times, and the organic phase was retained. The aqueous phase was then extracted with ethyl acetate. After the organic phases were combined, they were dried with anhydrous magnesium sulfate, and the solvent was removed with a rotary evaporator. The solid organic matter was completely dissolved in dichloromethane, and then slowly added dropwise to the petroleum ether solution, stirred evenly, and a precipitate was precipitated. The solid was filtered out, and then washed with anhydrous ethanol and petroleum ether in turn, and dried to obtain intermediate 3; Step 4: Under a nitrogen environment, the intermediate 3 is dissolved in a mixed solution of toluene, ethanol and water, and the raw material D is dissolved in a mixed solution of toluene, ethanol and water. The raw material D solution is slowly added to the intermediate 3 solution, potassium carbonate and tetrakis(triphenylphosphine)palladium are added thereto, and the mixture is stirred evenly. The mixture is heated to 70° C.-90° C. and refluxed for 4-12 hours. The reaction is detected by thin layer chromatography. After the reaction is completed, the mixture is cooled and filtered using diatomaceous earth to remove salt and catalyst. After the filtrate is cooled to room temperature, the mixture is washed with water three times, and the organic phase is retained. The aqueous phase is then extracted with dichloromethane; the organic phases are combined and concentrated, and a mixed solution of dichloromethane and petroleum ether is used as an eluent, and the mixture is purified by column chromatography to obtain the intermediate 4; Step 5: Under nitrogen environment, intermediate 4 is dissolved in toluene, raw material E is dissolved in toluene, and then raw material E is slowly added to the intermediate 4 solution, tri(dibenzylideneacetone)dipalladium, tri-tert-butylphosphine and sodium tert-butyl alcohol are added thereto, the temperature is raised to 100°C-120°C, and the reaction is carried out for 4-10 hours. After the reaction is completed, the temperature is lowered, and diatomaceous earth is used for filtering to remove salt and catalyst. After the filtrate is cooled to room temperature, it is washed three times with water, and the organic phase is retained, and then the aqueous phase is extracted with ethyl acetate; after the organic phases are combined, they are dried with anhydrous magnesium sulfate, and the solvent is removed with a rotary evaporator, and dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake is rinsed with petroleum ether for multiple times, and placed in a 60°C oven for drying for 5 hours to obtain chemical formula I; The specific synthetic route is as follows: In the above formula, X, R1, R2, R3, Ar1, Ar2, L are as defined in the above chemical formula I; X1 is selected from halogen.

7. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises the polycyclic aromatic organic electroluminescent material as claimed in claim 1 .

8. The organic electroluminescent device according to claim 7, characterized in that: The organic electroluminescent device comprises an anode, a cathode and at least one organic thin film layer arranged between the anode and the cathode; the organic thin film layer comprises the polycyclic aromatic organic electroluminescent material.

9. The organic electroluminescent device according to claim 8, characterized in that: The polycyclic aromatic organic electroluminescent material is used as a hole transport layer material of an organic electroluminescent device.

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