A polycyclic aromatic compound and an organic light-emitting device containing the same

Abstract

The present invention provides a polycyclic aromatic compound and an organic light-emitting device containing the same. The polycyclic aromatic compound has a structure shown in Formula I. The polycyclic aromatic compound provided by the present invention has the advantages that after being used in an organic electroluminescent device, the half-peak width is narrower, the color purity is improved, and the efficiency of the device is improved and the service life is increased.

Description

Technical Field

[0001] The invention belongs to the field of organic photoelectric materials, and in particular relates to a polycyclic aromatic compound and an organic light-emitting 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. OLED is an electroluminescent device formed by a multi-layer organic thin film structure.

[0003] The core organic light-emitting material of OLED display technology realizes the full color range based on the mixture of red light material, green light material and blue light material. The development of new light-emitting materials is the driving force for the continuous advancement of electroluminescent technology and is also a research hotspot in the organic electroluminescent industry. The development of new blue light organic electroluminescent materials achieves high luminous efficiency and better service life of the device. At the same time, blue light-emitting materials with narrow half-width and high color purity are the focus of the development of blue light-emitting materials.

[0004] At present, the multiple vibration effect (MR effect) is used to utilize the opposite vibrations of boron and heteroatoms such as nitrogen and oxygen to construct polycyclic aromatic compounds formed by condensing multiple aromatic rings with boron atoms and heteroatoms such as nitrogen and oxygen, that is, to prepare a special rigid material system containing boron atoms and heteroatoms such as nitrogen and oxygen. This type of fluorescent molecule has a high radiation transition rate, a narrow half-peak width, and high color purity, but the performance in device life and luminous efficiency is not particularly ideal, and the industrialization process of this technology still faces many key problems. Therefore, the development of new materials has always been a problem that technicians in this field need to solve. Summary of the invention

[0005] In view of the shortcomings of the prior art, the object of the present invention is to provide a polycyclic aromatic compound and an organic light-emitting device containing the same. The polycyclic aromatic compound provided by the present invention has the advantages that after being used in an organic electroluminescent device, the half-peak width is narrower, the color purity is improved, and the efficiency of the device is improved, and the service life is increased.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In one aspect, the present invention provides a polycyclic aromatic compound having a structure shown in Formula I:

[0008]

[0009] In the formula, R1-R5 are independently selected from unsubstituted C1-C30 alkyl groups or hydrogen atoms;

[0010] L is selected from a direct bond or an unsubstituted C6-C30 aryl group;

[0011] X1 is selected from O or S;

[0012] X2 is selected from O, S, NR6 or CR7R8, and R6-R8 is selected from unsubstituted C1-C30 alkyl or C6-C30 aryl;

[0013] Y1-Y5 are selected from CR9, and R9 is selected from hydrogen, deuterium, unsubstituted C1-C30 alkyl, and unsubstituted C6-C30 aryl.

[0014] Preferably, R1-R5 are independently selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, and the like.

[0015] Preferably, X2 is selected from O, S or , Represents the attachment site of the group.

[0016] Preferably, R9 is selected from hydrogen, deuterium or tert-butyl.

[0017] The above hydrogens may be independently substituted by deuterium or not.

[0018] Preferably, the polycyclic aromatic compound is selected from any one of the compounds represented by the following structural formulas:

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026] .

[0027] The organic electroluminescent compound of the present invention can be prepared by a synthetic method known to those skilled in the art. For example, it is preferably prepared by the following reaction scheme.

[0028]

[0029] Step 1 specifically includes the following steps: under nitrogen protection, raw material A (1.0 eq) and raw material B (1.0 eq) are dissolved in a toluene solution, sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq) are added, stirred evenly, heated to 110° C., and refluxed for 6 hours; after the reaction is completed, the temperature is slightly 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 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 intermediate 1;

[0030] Step 2 specifically includes the following steps: under nitrogen protection, raw material C (1.0 eq) and raw material D (1.0 eq) are dissolved in a toluene solution, sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq) are added, stirred evenly, heated to 110° C., and refluxed for 6 hours; after the reaction is completed, the temperature is slightly lowered, diatomaceous earth is used for filtering to remove salt and catalyst, and the filtrate is cooled to room temperature and washed three times with water, 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 intermediate 2;

[0031] Step 3 specifically includes the following steps:

[0032] Under nitrogen protection, raw material E (1.0 eq) and intermediate 1 (1.0 eq) were dissolved in toluene solution, sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq) were added, stirred evenly, heated to 120°C, and refluxed for 12 h. After the reaction was completed, the temperature was slightly lowered, filtered using diatomaceous earth to remove salt and catalyst, and the filtrate was cooled to room temperature and washed three times with water, the organic phase was retained, and 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. The mixture was dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake was rinsed with petroleum ether several times and dried in a 60°C oven for 7 h to obtain intermediate 3.

[0033] Step 4 specifically includes the following steps:

[0034] Under nitrogen protection, intermediate 2 (1.0 eq) and intermediate 3 (1.0 eq) were dissolved in 1,4-dioxane solution, sodium tert-butoxide (2.00 eq), palladium acetate (0.05 eq), and X-Phos (0.05 eq) were added and stirred evenly, and the temperature was raised to 100°C, and the reaction was refluxed for 10 hours. After the reaction was completed, the temperature was slightly lowered, and diatomaceous earth was used for filtration to remove salt and catalyst. After the filtrate was cooled to room temperature, a rotary evaporator was used to remove the solvent. The remaining substance was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=10:4) to obtain intermediate 4.

[0035] Step 5 specifically includes the following steps:

[0036] Under nitrogen atmosphere, intermediate 4 (1.0 eq) and anhydrous tert-butylbenzene were placed in a reaction bottle, nitrogen was replaced, and tert-butyl lithium pentane solution (5.0 eq) was added dropwise to the reaction system at -78 °C. After the addition was completed, the temperature was slowly raised to 65 °C and stirred for 3 h. The temperature was then lowered to -30 °C, and boron tribromide (5.0 eq) was added dropwise. The temperature was raised to room temperature, and stirring was continued for 1 h. N, N-diisopropylethylamine (10.0 eq) was added dropwise to the reaction system. The temperature was raised to 145 °C and the reaction was continued for 4 h. After monitoring the reaction, the reaction was cooled to room temperature, and a saturated sodium bicarbonate aqueous solution was added dropwise to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was concentrated and purified by column chromatography (eluent: V (ethyl acetate): V (petroleum ether) = 1:20) to obtain Formula I.

[0037] On the other hand, the present invention provides an organic electroluminescent device, comprising a first electrode, a second electrode and at least one organic layer, wherein the organic layer is located between the first electrode and the second electrode, and at least one of the organic layers contains the polycyclic aromatic compound as described above.

[0038] Preferably, the organic electroluminescent device comprises a light-emitting layer, and the light-emitting layer comprises the polycyclic aromatic compound as described above.

[0039] Preferably, the light-emitting layer comprises a host material and a doping material, and the doping material is the polycyclic aromatic compound as described above.

[0040] Preferably, the mixing ratio of the main material and the doping material is (85:15) to (99:1), for example, 85:15, 86:14, 87:13, 88:12, 89:11, 90:10, 95:5, 98:2, etc.

[0041] Preferably, the organic layer further comprises one or a combination of at least two of a hole injection layer, a hole transport layer, an electron blocking layer, a luminescence auxiliary layer, a hole blocking layer, an electron transport layer or an electron injection layer.

[0042] The organic light-emitting device provided by the present invention can be used in any of the following electronic devices for display or light emission: computers, tablet computers, televisions, phones, virtual reality or augmented reality displays, etc.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The compound of the present invention introduces a substituted furan group on the basis of the parent core, providing a highly conjugated electron distribution system of a polycyclic aromatic compound, allowing the molecules to be stacked effectively and orderly, thereby exerting the best carrier transmission and migration under a certain electric field. At the same time, some rigid molecular groups with high stereo hindrance are synthesized in the molecular structure, and the molecules combine long-range interaction and delocalization in a rather unique way, causing the effect of short-range high radiation attenuation rate. The charge density reorganization can minimize the singlet-triplet gap, and the device life prepared by using the doping material of the present invention is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is the H NMR spectrum of compound 1. DETAILED DESCRIPTION

[0046] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0047] Example 1

[0048] Compound D-1 needs to be synthesized via the following pathway:

[0049]

[0050] Step a: Put the raw material Da (1.0 eq) and the raw material Db (1.1 eq) into a mixed solution of toluene, ethanol and water, then ventilate 3 times, add potassium carbonate (2.0 eq) and tetrakis(triphenylphosphine)palladium (Pd(pph3)4) (0.01 eq) under nitrogen protection, stir evenly, heat to 90°C, and reflux for 8 hours; after the reaction is completed, lower the temperature slightly, filter with diatomaceous earth to remove salt and catalyst, cool the filtrate to room temperature, wash with water three times, retain the organic phase, and then extract the aqueous phase with ethyl acetate; after the organic phases are combined, dry with anhydrous magnesium sulfate, and remove the solvent with a rotary evaporator to obtain intermediate d.

[0051] Step b specifically includes the following steps: under nitrogen protection, dissolving the raw material Dc (1.0 eq) and the intermediate d (1.0 eq) in a toluene solution, adding sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq), stirring evenly, heating to 110° C., and reflux reaction for 4 hours; after the reaction is completed, the temperature is slightly lowered, and diatomaceous earth is used for filtering to remove salt and catalyst, and the filtrate is cooled to room temperature, washed with water three times, 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 6 hours to obtain compound D-1;

[0052]

[0053] Step 1 specifically includes the following steps: under nitrogen protection, raw material A (1.0 eq) and raw material B (1.0 eq) are dissolved in a toluene solution, sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq) are added, stirred evenly, heated to 110° C., and refluxed for 6 hours; after the reaction is completed, the temperature is slightly 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 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 intermediate 1;

[0054] Step 2 specifically includes the following steps: under nitrogen protection, raw material C (1.0 eq) and raw material D (1.0 eq) are dissolved in a toluene solution, sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq) are added, stirred evenly, heated to 110° C., and refluxed for 6 hours; after the reaction is completed, the temperature is slightly lowered, diatomaceous earth is used for filtering to remove salt and catalyst, and the filtrate is cooled to room temperature and washed three times with water, 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 intermediate 2;

[0055] Step 3 specifically includes the following steps:

[0056] Under nitrogen protection, raw material E (1.0 eq) and intermediate 1 (1.0 eq) were dissolved in toluene solution, sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq) were added, stirred evenly, heated to 120°C, and refluxed for 12 h. After the reaction was completed, the temperature was slightly lowered, filtered using diatomaceous earth to remove salt and catalyst, and the filtrate was cooled to room temperature and washed three times with water, the organic phase was retained, and 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. The mixture was dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake was rinsed with petroleum ether several times and dried in a 60°C oven for 7 h to obtain intermediate 3.

[0057] Step 4 specifically includes the following steps:

[0058] Under nitrogen protection, intermediate 2 (1.0 eq) and intermediate 3 (1.0 eq) were dissolved in 1,4-dioxane solution, sodium tert-butoxide (2.00 eq), palladium acetate (0.05 eq), and X-Phos (0.05 eq) were added and stirred evenly, and the temperature was raised to 100°C, and the reaction was refluxed for 10 hours. After the reaction was completed, the temperature was slightly lowered, and diatomaceous earth was used for filtration to remove salt and catalyst. After the filtrate was cooled to room temperature, a rotary evaporator was used to remove the solvent. The remaining substance was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=10:4) to obtain intermediate 4.

[0059] Step 5 specifically includes the following steps:

[0060] Under nitrogen atmosphere, intermediate 4 (1.0 eq) and anhydrous tert-butylbenzene were placed in a reaction bottle, nitrogen was replaced, and tert-butyl lithium pentane solution (5.0 eq) was added dropwise to the reaction system at -78 °C. After the addition was completed, the temperature was slowly raised to 65 °C and stirred for 3 h. The temperature was then lowered to -30 °C, and boron tribromide (5.0 eq) was added dropwise. The temperature was raised to room temperature and stirred for 1 h. N, N-diisopropylethylamine (10.0 eq) was added dropwise to the reaction system. The temperature was raised to 145 °C and the reaction was continued for 4 h. After monitoring the reaction, the reaction was cooled to room temperature, and a saturated sodium bicarbonate aqueous solution was added dropwise to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was concentrated and purified by column chromatography (eluent: V (ethyl acetate): V (petroleum ether) = 1:20) to obtain compound 1. (Yield: 32.5%, Mw: 1103.79).

[0061] The obtained compound 1 was tested and analyzed, and the results were as follows:

[0062] HPLC purity: >99.95%.

[0063] Mass spectrometry test: theoretical value is 1103.60; tested value is 1103.79.

[0064] Elemental Analysis:

[0065] Calculated values: C, 83.74; H, 7.12; B, 0.98; N, 3.81; O, 1.45; S, 2.90.

[0066] The test values ​​are: C, 82.82; H, 7.43; B, 1.16; N, 3.99; O, 1.71; S, 3.22.

[0067] The H NMR spectrum of compound 1 is as follows Figure 1 shown.

[0068] Example 2

[0069] Compound D-1 needs to be synthesized via the following pathway:

[0070]

[0071] Step a specifically comprises the following steps: under nitrogen protection, dissolving raw material Da (1.0 eq) and raw material Db (1.0 eq) in toluene solution, adding sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), tri-tert-butylphosphine (0.05 eq), stirring evenly, heating to 110° C., and reflux reaction for 4 hours; after the reaction is completed, the temperature is slightly lowered, diatomaceous earth is used for filtering, salt and catalyst are removed, the filtrate is cooled to room temperature, washed three times with water, 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 6 hours to obtain compound D-1;

[0072]

[0073] Step 1 specifically includes the following steps: under nitrogen protection, raw material A (1.0 eq) and raw material B (1.0 eq) are dissolved in a toluene solution, sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq) are added, stirred evenly, heated to 110° C., and refluxed for 6 hours; after the reaction is completed, the temperature is slightly 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 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 intermediate 1;

[0074] Step 2 specifically includes the following steps: under nitrogen protection, raw material C (1.0 eq) and raw material D (1.0 eq) are dissolved in a toluene solution, sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq) are added, stirred evenly, heated to 110° C., and refluxed for 6 hours; after the reaction is completed, the temperature is slightly lowered, diatomaceous earth is used for filtering to remove salt and catalyst, and the filtrate is cooled to room temperature and washed three times with water, 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 intermediate 2;

[0075] Step 3 specifically includes the following steps:

[0076] Under nitrogen protection, raw material E (1.0 eq) and intermediate 1 (1.0 eq) were dissolved in toluene solution, sodium tert-butoxide (2.00 eq), tri(dibenzylideneacetone)dipalladium (0.01 eq), and tri-tert-butylphosphine (0.05 eq) were added, stirred evenly, heated to 120°C, and refluxed for 12 h. After the reaction was completed, the temperature was slightly lowered, filtered using diatomaceous earth to remove salt and catalyst, and the filtrate was cooled to room temperature and washed three times with water, the organic phase was retained, and 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. The mixture was dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake was rinsed with petroleum ether several times and dried in a 60°C oven for 7 h to obtain intermediate 3.

[0077] Step 4 specifically includes the following steps:

[0078] Under nitrogen protection, intermediate 2 (1.0 eq) and intermediate 3 (1.0 eq) were dissolved in 1,4-dioxane solution, sodium tert-butoxide (2.00 eq), palladium acetate (0.05 eq), and X-Phos (0.05 eq) were added and stirred evenly, and the temperature was raised to 100°C, and the reaction was refluxed for 10 hours. After the reaction was completed, the temperature was slightly lowered, and diatomaceous earth was used for filtration to remove salt and catalyst. After the filtrate was cooled to room temperature, a rotary evaporator was used to remove the solvent. The remaining substance was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=10:4) to obtain intermediate 4.

[0079] Step 5 specifically includes the following steps:

[0080] Under nitrogen atmosphere, intermediate 4 (1.0 eq) and anhydrous tert-butylbenzene were placed in a reaction bottle, nitrogen was replaced, and tert-butyl lithium pentane solution (5.0 eq) was added dropwise to the reaction system at -78 °C. After the addition was completed, the temperature was slowly raised to 65 °C and stirred for 3 h. The temperature was then lowered to -30 °C, and boron tribromide (5.0 eq) was added dropwise. The temperature was raised to room temperature, and stirring was continued for 1 h. N, N-diisopropylethylamine (10.0 eq) was added dropwise to the reaction system. The temperature was raised to 145 °C and the reaction was continued for 4 h. After monitoring the reaction, the reaction was cooled to room temperature, and a saturated sodium bicarbonate aqueous solution was added dropwise to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was concentrated and purified by column chromatography (eluent: V (ethyl acetate): V (petroleum ether) = 1:20) to obtain compound 2. (Yield: 33.1%, Mw: 1129.78).

[0081] The obtained compound 2 was tested and analyzed, and the results were as follows:

[0082] HPLC purity: >99.95%.

[0083] Mass spectrometry test: theoretical value is 1129.65; tested value is 1129.78.

[0084] Elemental Analysis:

[0085] Calculated values: C, 85.00; H, 7.49; B, 0.96; N, 3.72; S, 2.84.

[0086] The test values ​​are: C, 84.72; H, 7.63; B, 1.12; N, 3.88; S,3.08.

[0087] The synthesis methods of other compounds are the same as those in the above examples, which are not described one by one here. The mass spectra, molecular formulas and yields of other synthesis examples are shown in Table 1 below:

[0088] Table 1 Mass spectrometry analysis and yield of the examples

[0089]

[0090]

[0091] Device Example 1: Fabrication of an organic electroluminescent device containing Compound 1

[0092] a. ITO anode: Wash the 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.

[0093] b. HIL (hole injection layer): vacuum evaporate the hole injection layer materials HT-1 and P-dopant at an evaporation rate of 1Å / s. The evaporation rate ratio of HT-1 to P-dopant is 97:3, and the thickness is 10nm;

[0094] c. HTL (hole transport layer): 130nm of HT-1 was vacuum evaporated on the hole injection layer at a deposition rate of 1Å / s as the hole transport layer;

[0095] d. Light-emitting auxiliary layer: 10 nm EBL-1 was vacuum-deposited on the hole transport layer at a deposition rate of 0.5 Å / s as a light-emitting auxiliary layer;

[0096] e. EML (light-emitting layer): Then, on the above-mentioned light-emitting auxiliary layer, a host material (Host) with a thickness of 20 nm and the compound 1 provided in the above embodiment as a doping material (Dopant) are vacuum evaporated at a deposition rate of 1Å / s as a light-emitting layer; wherein the evaporation rate ratio of Host to Dopant is 98:2.

[0097] f. HBL (hole blocking layer): 5 nm of HB-1 was vacuum-deposited on the light-emitting layer at a deposition rate of 0.5 Å / s as a hole blocking layer;

[0098] g. ETL (electron transport layer): 30 nm of ET-1 was vacuum-deposited on the hole blocking layer at a deposition rate of 1 Å / s as the electron transport layer.

[0099] h. EIL (electron injection layer): 1.0 nm Yb film layer was evaporated at a deposition rate of 0.5 Å / s to form an electron injection layer.

[0100] i. Cathode: 100nm of metal Al was evaporated at an evaporation rate of 1Å / s to obtain an OLED device.

[0101] The required material structure is as follows:

[0102]

[0103] Device Example 2-Device Example 30 Referring to the above method, the compound 1 used in Device Example 1 is replaced by compounds 2, 4, 6, 11, 13, 19, 21, 24, 26, 30, 33, 36, 41, 43, 51, 55, 57, 59, 66, 70, 75, 79, 83, 86, 89, 92, 96, 100, and 108 as doping materials to prepare corresponding organic electroluminescent devices.

[0104] Device Comparative Example 1-2: This comparative example provides an organic electroluminescent device. The only difference between the preparation method of the organic electroluminescent device and the device embodiment 1 is that the organic electroluminescent device uses existing comparative compounds a and b to replace the doping material in the above device embodiment 1 for evaporation to prepare device comparative examples 1-2. The chemical structural formulas of comparative compounds a and b are:

[0105] .

[0106] The driving voltage, luminous efficiency, BI value and life of the organic electroluminescent devices obtained from the device embodiments 1 to 30 and the device comparative examples 1 to 2 were characterized at a brightness of 1000 (nits). The test results are shown in Table 2 below:

[0107] Table 2

[0108]

[0109] As can be seen from the above table, the organic electroluminescent device prepared using the compound provided by the present invention as the doping material in the light-emitting layer has greatly improved luminous efficiency and life compared with the organic electroluminescent device prepared using the comparative compound a or b as the doping material.

[0110] The applicant declares that the present invention illustrates the compounds and organic electroluminescent devices of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A polycyclic aromatic compound, characterized in that: The polycyclic aromatic compound has a structure shown in Formula I: In the formula, R1-R5 are independently selected from unsubstituted C1-C30 alkyl groups or hydrogen atoms; L is a direct key; X1 is selected from O or S; X2 is selected from O, S or , The attachment site of the representative group; Y1-Y5 is selected from CR9, R9 is selected from hydrogen, deuterium, unsubstituted C1-C30 alkyl, unsubstituted C6-C30 aryl; The above hydrogens may be independently substituted by deuterium or not.

2. The polycyclic aromatic compound according to claim 1, characterized in that R1-R5 are independently selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl or pentyl.

3. The polycyclic aromatic compound according to claim 1, characterized in that: R9 is selected from hydrogen, deuterium or tert-butyl.

4. The polycyclic aromatic compound according to claim 1, characterized in that The polycyclic aromatic compound is selected from any one of the compounds represented by the following structural formulas: 。 5. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises a first electrode, a second electrode and at least one organic layer, wherein the organic layer is located between the first electrode and the second electrode, and at least one organic layer comprises the polycyclic aromatic compound as described in any one of claims 1 to 4.

6. The organic electroluminescent device according to claim 5, characterized in that: The organic electroluminescent device comprises a light-emitting layer, and the light-emitting layer comprises the polycyclic aromatic compound according to any one of claims 1 to 4.

7. The organic electroluminescent device according to claim 6, characterized in that: The light-emitting layer includes a host material and a doping material, and the doping material is a polycyclic aromatic compound as described in any one of claims 1 to 4.

8. The organic electroluminescent device according to claim 7, characterized in that: The mixing ratio of the main material to the doping material is (85:15) to (99:1).

9. The organic electroluminescent device according to claim 5, characterized in that: The organic layer further includes one or a combination of at least two of a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting auxiliary layer, a hole blocking layer, an electron transport layer or an electron injection layer.

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