Benzonaphthofuryl and anthryl-based blue light host material and application thereof in organic electroluminescent device

Abstract

The invention provides a blue light host material based on benzonaphthofuryl and anthryl and application of the blue light host material in an organic electroluminescent device, a novel compound serving as the blue light host material in a luminescent layer takes a rigid benzonaphthofuryl group and deuterated anthryl as a host structure, and D has lower activity than H, so that the blue light host material can be applied to organic electroluminescent devices. A C-D bond on anthryl is more stable than a C-H bond, the non-radiative transition of the compound is reduced, the structure is more stable, and the service life and efficiency of the material applied to a device are improved. Aryl is further introduced, a conjugated system can be effectively prolonged, the luminous efficiency can be improved, the HOMO energy level of the aryl is generally high, the LUMO energy level of the aryl is generally low, the energy gap (HOMO-LUMO energy range) of the aryl is large, electron transition is not prone to overspeed, and therefore high stability is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic electroluminescent materials, and in particular, relates to a blue light host material based on benzonaphthofuranyl and anthracene and an application thereof in an organic electroluminescent device. Background Art

[0002] Organic light-emitting diodes (OLED) are a display lighting technology that has gradually developed in recent years. Especially in the display industry, OLED displays have attracted widespread attention due to their advantages such as high response, high contrast, and flexibility. The pixel units of full-color OLED displays on the market are currently composed of three primary colors: red, green, and blue. Compared with red and green materials, blue materials have higher energy in three-color light-emitting devices, which can be transferred to low-energy organic light-emitting materials such as green, yellow, and red. According to the principle of three primary colors, blue light emission is the basis for achieving white and color display. In addition, the life of blue OLED is still insufficient compared to red and green OLED. Recent studies have shown that in blue OLED devices, compared with other functional layers except the light-emitting layer, the BDE (bond dissociation energy) of the main molecule in the anionic state in the light-emitting layer has a significant impact on the life; although the BDE of the anionic state of other functional layers such as the hole blocking layer material except the light-emitting layer is lower than the BDE of the anionic state of the main material, the electrochemical stability of the main material has the greatest impact on the device life.

[0003] At present, the light-emitting layer in blue organic electroluminescent devices almost all uses a host-guest doped light-emitting system, that is, electroluminescence is achieved by doping the host material with the guest doping material. Commonly used blue fluorescent devices mainly use anthracene-based host materials. Studies have found that the efficiency of blue light devices can be improved by introducing fragments containing highly electronegative oxygen atoms such as dibenzofuran into the host material. However, the anthracene-based host material containing dibenzofuran fragments has a low BDE of carbon-oxygen bonds in the anionic state, which will lead to a decrease in the life of the organic electroluminescent device.

[0004] Therefore, there is an urgent need to develop a new, long-life host material for the light-emitting layer of organic electroluminescent devices. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a blue light host material based on benzonaphthofuran and anthracene and its application in organic electroluminescent devices. As a new type of compound of the blue light host material in the light-emitting layer, the rigid benzonaphthofuran group and the deuterated anthracene group are used as the main structure. Because D has lower activity than H, the CD bond on the anthracene group is more stable than the CH bond, the non-radiative transition of the compound is reduced, and the structure is more stable, which is conducive to the improvement of the life and efficiency of the material after being used in the device. Further introduction of aromatic groups can effectively extend the conjugated system and improve the luminous efficiency. The HOMO energy level of aromatic groups is usually higher and the LUMO energy level is usually lower, which makes the energy gap (HOMO-LUMO energy difference) of aromatic groups larger, and the electronic transition is not easy to be over-accelerated, so it has higher stability.

[0006] To achieve the above object, the present invention provides the following technical solutions: A blue light host material based on benzonaphthofuranyl and anthracene, wherein the blue light host material has a general structural formula shown in Chemical Formula I: , Wherein, Ar is independently selected from phenyl, and the position of the phenyl ring on the dibenzofuran group is 1, 2, 2, 3 or 3, 4, and the connection position is as follows: ; R 1 are independently selected from substituted or unsubstituted C 6 -C 30 Aryl, substituted or unsubstituted C 2 -C 30 Heteroaryl, or a combination of the above aryl and heteroaryl, wherein the heteroatom in the heteroaryl contains at least one or more of O, S, N, Si, and Se; R 2 are independently selected from C 6 -C 30 Aryl; Furthermore, the structure of Chemical Formula I includes Chemical Formula I-A, Chemical Formula I-B, and Chemical Formula I-C: .

[0007] Furthermore, R 1 are independently selected from substituted or unsubstituted C 6 -C 18 Aryl, substituted or unsubstituted C 5 -C 24 Heteroaryl, or a combination of the above aryl and heteroaryl, wherein the heteroatom in the heteroaryl contains at least one or more of O, S, N, Si, and Se.

[0008] Furthermore, R 2 are independently selected from C 6 -C 18 Aryl.

[0009] Furthermore, the chemical formula I has the following chemical formula I-1 to chemical formula I-9:

[0010] Furthermore, R 1 Independently selected from the following groups or any combination:

[0011] Among them, R 3 represents hydrogen, unsubstituted C 1 -C 6 alkyl.

[0012] Furthermore, R 2 Independently selected from the following groups or any combination: , R 4 -R 12 are each independently selected from hydrogen, deuterium, C 1 -C 6 The alkyl group; n 4 Each is independently selected from 0, 1, 2, 3, 4, 5; n 5 、n 8 Each is independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9; n 6 、n 11 Each is independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13; n 7 、n 9 Each is independently selected from 0, 1, 2, 3, 4, 5, 6, 7; n 10 、n 12 Each is independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11; In all the above formulae, * represents a connection point.

[0013] The "substituted" in the above substituted or unsubstituted is selected from C 1 -C 10The alkyl group is preferably one or more of methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylbutyl, 1-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, 1-methylhexyl, cyclopentane and cyclohexane.

[0014] Furthermore, the blue light host material is selected from any one of the compounds represented by the following structural formulas:

[0015]

[0016] The present invention also provides an application of the above-mentioned blue light host material based on benzonaphthofuranyl and anthracene in an organic electroluminescent device.

[0017] The blue light host material of the present invention can be prepared by a synthetic method known to those skilled in the art; or can be prepared by the following reaction process:

[0018] Specific preparation method: Step 1 specifically includes the following processes: Raw material A (1.0 eq), raw material B (1.0-1.3 eq) and potassium carbonate (2.0-4.0 eq) were added to a reaction flask, followed by a mixed solution of toluene, ethanol and water (V:V:V = 3:1:1), and tetrakis(triphenylphosphine)palladium (0.01-0.03 eq) was added under nitrogen protection. The temperature was raised to 80°C-95°C, and the reaction was refluxed for 3-20 hours. The reaction was detected by thin layer chromatography. 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, dichloromethane and water were added for extraction and separation, and the organic phase was retained and concentrated. The intermediate 1 was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:3-1:10) to obtain intermediate 1.

[0019] Step 2 specifically includes the following steps: Add intermediate 1 (1.0 eq) and N-bromosuccinimide NBS (1.1 eq) into a reaction flask, then add dichloromethane and react for 2-8 h at room temperature with stirring; detect the reaction by thin layer chromatography. After the reaction is completed, extract three times with water, retain the organic phase, combine the organic phases and concentrate, and purify by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:8) to obtain intermediate 2.

[0020] This step is a bromination reaction between the anthracene-containing intermediate and N-bromosuccinimide. 2 There is an active hydrogen at the para position connecting the anthracene group, and the degree of substitution of bromine at this position is the highest.

[0021] References: 1. "Basic Organic Chemistry" (3rd edition, Volume 1), Xing Qiyi, Pei Weiwei, Xu Ruiqiu, Pei Jian, Publisher: Higher Education Press, Publication Date: 2005.06, ISBN: 978-7-04-016637-8, Page 472-473. 2. Peng Ling. Design, synthesis and application of phenyl-bridged dianthryl organic deep blue luminescent materials in organic electroluminescent devices[D]. South China University of Technology, 2019, 36-38. Step 3 specifically includes the following processes: Raw material D (1.0 eq), raw material C (1.0-1.3 eq) and potassium carbonate (2.0-4.0 eq) were added to a reaction flask, followed by a mixed solution of toluene, ethanol and water (V:V:V = 3:1:1), and tetrakis(triphenylphosphine)palladium (0.01-0.03 eq) was added under nitrogen protection. The temperature was raised to 80°C-95°C, and the reaction was refluxed for 3-20 hours. The reaction was detected by thin layer chromatography. 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, dichloromethane and water were added for extraction and separation. The organic phase was retained and concentrated, and intermediate 3 was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:3-1:10) to obtain intermediate 3.

[0022] Step 4 specifically includes the following processes: Add intermediate 3 (1.0 eq), pinacol diboron (1.0-2.0 eq) and potassium acetate (2.0-4.0 eq) to a reaction flask, then add 1,4-dioxane, add tri(dibenzylideneacetone)dipalladium (0.02-0.10 eq) and X-Phos (0.1-0.2 eq) under nitrogen protection, heat to 120°C, and reflux for 4-20 hours; detect the reaction by thin layer chromatography, after the reaction is completed, slightly lower the temperature, filter with diatomaceous earth to remove salt and catalyst, cool the filtrate to room temperature, extract with dichloromethane and water, separate the liquids, retain the organic phase and concentrate, purify by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:3-1:10) to obtain intermediate 4.

[0023] Step 5 specifically includes the following processes: Intermediate 4 (1.0-1.3eq), intermediate 2 (1.0eq) and potassium carbonate (2.0-4.0eq) are added to a reaction flask, followed by a mixed solution of toluene, ethanol and water (V:V:V = 3:1:1), and tetrakis(triphenylphosphine)palladium (0.01-0.03eq) is added under nitrogen protection, and the temperature is raised to 80°C-95°C, and the reaction is refluxed for 3-20h; the reaction is detected by thin layer chromatography, and after the reaction is completed, the temperature is slightly lowered, and diatomaceous earth is used for filtering to remove salt and catalyst. After the filtrate is cooled to room temperature, dichloromethane and water are added for extraction and separation, and the organic phase is retained and concentrated, and a mixed solution of dichloromethane and petroleum ether (V:V=1:3-1:10) is used for purification by column chromatography to obtain chemical formula I.

[0024] In the above formula, R 1 , R 2 , Ar is as defined in the above chemical formula I, X represents or .

[0025] In particular, for complex raw materials that have not been disclosed before, classic Suzuki coupling reaction and bromination reaction are used to synthesize and apply them to the present invention.

[0026] Beneficial effects of the present invention: 1) The present invention provides a blue light host material based on benzonaphthofuran and anthracene. The novel compound effectively exhibits the characteristics of a blue light host material. It has a rigid benzonaphthofuran group and a deuterated anthracene group as the parent core, and has good thermal stability, low driving voltage, excellent luminous efficiency and service life.

[0027] Among them, the inherently rigid benzonaphthofuran group helps to improve the thermal stability of the material, thereby enhancing the service life of the device. The fragments of oxygen atoms with high electronegativity in the benzonaphthofuran group can effectively improve the luminescence efficiency of blue light devices. Further introducing a substituent (aryl or heteroaryl) on the benzonaphthofuran group can effectively extend the conjugated system, enhance the conjugation effect, effectively improve the fluorescence quantum efficiency, and avoid the localization of carrier migration, thereby increasing the migration rate, thereby reducing the voltage and improving the luminescence efficiency of the device.

[0028] 2) The present invention introduces deuterated anthracene groups, which have high fluorescence quantum efficiency, especially in the blue light region. Its rigid planar structure reduces the possibility of non-radiative transitions, effectively improves electron mobility, and thus improves the luminous efficiency of blue light. Its lowest unoccupied molecular orbital (LUMO) energy level is low, which is conducive to the injection and transmission of electrons. The structure of the anthracene group is relatively stable and can withstand high temperatures, so that its structure is not easy to change during the evaporation process, thereby improving the service life of its device. In addition, the anthracene group also has a wide bandgap, which makes it have strong absorption and emission capabilities in the blue light region. Deuterated anthracene groups can reduce the vibration frequency of molecules, reduce the thermal motion of molecules, help improve the thermal stability of materials, and lessen the material explanation caused by temperature increase, thereby extending the service life of materials. D has lower activity than H, and the CD bond on the anthracene group is more stable than the CH bond. The non-radiative transition of the compound is reduced, and the structure is more stable, which is conducive to improving the life and efficiency of the material after it is used in the device.

[0029] In addition, a capping group (deuterated or non-deuterated aromatic group) is introduced on the anthracene group. The HOMO energy level of the aromatic group is usually higher and the LUMO energy level is usually lower. This makes the energy gap (HOMO-LUMO energy difference) of the aromatic group larger, and the electron transition is not easy to be too fast, so it has higher stability, especially the deuterated aromatic group, which makes the device performance better. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is the hydrogen nuclear magnetic resonance spectrum of compound 1 prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention are described clearly and completely below. 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.

[0032] 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.

[0033] Example 1

[0034] Raw materials A-1 and B-1 are prior art and are directly used in the synthesis reaction.

[0035] Step 1 specifically includes the following processes: The raw material A-1 (1.0 eq, CAS number: 2626917-17-5), pinacol diboron (1.2 eq) and potassium acetate (2.0 eq) were added to the reaction bottle, and then 1,4-dioxane was added. Tris(dibenzylideneacetone)dipalladium (0.02 eq) and X-Phos (0.1 eq) were added under nitrogen protection, and the temperature was raised to 120°C, and the reaction was refluxed for 15 hours. The reaction was detected by thin layer chromatography. 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, dichloromethane and water were added for extraction and separation. The organic phase was retained and concentrated, and a mixed solution of dichloromethane and petroleum ether (V:V=1:4) was used for purification by column chromatography to obtain intermediate 1 (yield: 74.4%).

[0036] Step 2 specifically includes the following processes: Intermediate 1 (1.0 eq), raw material B-1 (1.0 eq, CAS number: 2377545-68-9) and potassium carbonate (3.0 eq) were added to a reaction flask, followed by a mixed solution of toluene, ethanol and water (V:V:V = 3:1:1), and tetrakis(triphenylphosphine)palladium (0.03 eq) was added under nitrogen protection. The temperature was raised to 95°C and refluxed for 8 hours. The reaction was detected by thin layer chromatography. After the reaction was completed, the temperature was slightly lowered and filtered using diatomaceous earth to remove salt and catalyst. After the filtrate was cooled to room temperature, dichloromethane and water were added for extraction and separation. The organic phase was retained and concentrated, and a mixed solution of dichloromethane and petroleum ether (V:V=1:5) was used for purification by column chromatography to obtain compound 1 (yield: 81.4%).

[0037] The obtained compound 1 was tested and analyzed, and the results were as follows: HPLC purity: >99.8%.

[0038] Mass spectrometry test: The model is Waters XEVO TQD mass spectrometer, using ESI source.

[0039] Found value ((ESI, m / Z): [M+H]+): 559.53.

[0040] Elemental analysis: Calculated values: C, 90.12; H, 7.02; O, 2.86; Found values: C, 89.88; H,7.16; O, 3.01.

[0041] H NMR spectrum: Figure 1 (Compound 1) shown.

[0042] Example 2

[0043] The raw material C-187 is prior art and is directly used in the synthesis reaction.

[0044] Step 1 specifically includes the following processes: Raw material A-187 (1.2 eq, CAS number: 2568850-23-5), raw material B-187 (1.0 eq, CAS number: 1822310-41-7) and potassium carbonate (3.0 eq) were added to a reaction flask, followed by a mixed solution of toluene, ethanol and water (V:V:V = 3:1:1), and tetrakis(triphenylphosphine)palladium (0.03 eq) was added under nitrogen protection. The temperature was raised to 95°C and refluxed for 5 hours. The reaction was detected by thin layer chromatography. 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, dichloromethane and water were added for extraction and separation. The organic phase was retained and concentrated, and intermediate 1 was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:4) to obtain intermediate 1 (yield: 74.7%).

[0045] Step 2 specifically includes the following processes: Intermediate 1 (1.0 eq), pinacol diboron (1.2 eq) and potassium acetate (2.0 eq) were added to a reaction flask, followed by 1,4-dioxane, and tri(dibenzylideneacetone)dipalladium (0.02 eq) and X-Phos (0.1 eq) were added under nitrogen protection. The temperature was raised to 120°C and refluxed for 18 h. The reaction was detected by thin layer chromatography. After the reaction was completed, the temperature was slightly lowered and filtered using diatomaceous earth to remove salt and catalyst. After the filtrate was cooled to room temperature, dichloromethane and water were added for extraction and separation. The organic phase was retained and concentrated. The intermediate 2 (yield: 72.8%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:4)

[0046] Step 3 specifically includes the following processes: Intermediate 2 (1.0 eq), raw material C-187 (1.0 eq, CAS number: 2409797-85-7) and potassium carbonate (3.0 eq) were added to a reaction flask, followed by a mixed solution of toluene, ethanol and water (V:V:V = 3:1:1), and tetrakis(triphenylphosphine)palladium (0.03 eq) was added under nitrogen protection. The temperature was raised to 95°C and refluxed for 10 hours. The reaction was detected by thin layer chromatography. After the reaction was completed, the temperature was slightly lowered and filtered using diatomaceous earth to remove salt and catalyst. After the filtrate was cooled to room temperature, dichloromethane and water were added for extraction and separation. The organic phase was retained and concentrated, and compound 187 (yield: 80.5%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:5) to obtain compound 187 (yield: 80.5%).

[0047] The obtained compound 187 was tested and analyzed, and the results were as follows: HPLC purity: >99.6%.

[0048] Mass spectrometry test: The model is Waters XEVO TQD mass spectrometer, using ESI source.

[0049] Test value (ESI, m / Z): [M + H] + ):770.57 Calculated values: C, 90.36; H, 5.49; O, 4.15; Test values: C, 90.13; H, 5.64; O, 4.31.

[0050] Example 3-38 The following compounds were synthesized by referring to the synthesis methods of Examples 1 to 2, and tested using a Waters XEVOTQD mass spectrometer with low precision. The ESI source was used for testing, and the mass spectrometry test values ​​are shown in Table 1 below.

[0051] Table 1 Mass spectrometry test values ​​of Examples 3-38

[0052]

[0053] In addition, other compounds of the present invention can be obtained by referring to the synthesis methods of the above-mentioned embodiments, so they are not listed one by one here.

[0054] Device Example 1: Preparation of an organic electroluminescent device The structure of the prepared OLED device is: ITO anode / HIL / HTL / Prime / EML / HBL / ETL / EIL / cathode / CPL.

[0055] a. ITO anode: The ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 1500 angstroms was cleaned twice in distilled water, ultrasonically cleaned for 30 minutes, and then repeatedly cleaned twice with distilled water, ultrasonically cleaned for 10 minutes. After washing, it was ultrasonically cleaned with methanol, acetone, and isopropanol in sequence (5 minutes each time), dried, and then transferred to a plasma cleaning machine for washing for 5 minutes. It was then sent to a vapor deposition machine, and the substrate was used as the anode, and other functional layers were deposited on it in sequence.

[0056] b. HIL (hole injection layer): Hole injection layer materials HT and P-dopant were vacuum evaporated at an evaporation rate of 1 angstrom / second. The chemical formula is shown below. The evaporation rate ratio of HT and P-dopant is 97:3, and the thickness is 10 nm.

[0057] c. HTL (hole transport layer): 130 nm of HT was vacuum-deposited on the hole injection layer at a deposition rate of 1.5 Å / s as the hole transport layer.

[0058] d. Prime (luminescence auxiliary layer): 5 nm of Prime is vacuum-deposited on the hole transport layer at a deposition rate of 0.5 Å / s as a luminescence auxiliary layer.

[0059] e. EML (luminescent layer): Then, on the above-mentioned luminescent auxiliary layer, 1 / s, vacuum evaporated the main material (Compound 1 provided in the above embodiment) and the dopant material (Dopant) as the light-emitting layer, with a total thickness of 30nm, wherein the evaporation rate ratio of the main compound to the dopant compound is 98:2.

[0060] f. HBL (hole blocking layer): A hole blocking layer HB with a thickness of 5 nm was vacuum-deposited at a deposition rate of 0.5 Å / s.

[0061] g. ETL (electron transport layer): ET and Liq with a thickness of 30 nm were vacuum-deposited at a deposition rate of 1 angstrom / second as the electron transport layer, where the deposition rate ratio of ET to Liq was 50:50.

[0062] h. EIL (electron injection layer): 1 nm of Yb film was evaporated at a deposition rate of 0.5 Å / s to form an electron injection layer.

[0063] i. Cathode: 13 nm of magnesium and silver were evaporated at an evaporation rate ratio of 1 angstrom / s, and the evaporation rate ratio was 1:9 to obtain an OLED device.

[0064] j. CPL (covering layer): CPL with a thickness of 65 nm was vacuum-deposited on the cathode at a deposition rate of 1 Å / s as a covering layer.

[0065] k. Then the vapor-deposited substrate is packaged. First, the cleaned cover is coated with UV glue using glue coating equipment, and then the coated cover is moved to the pressing section, the vapor-deposited substrate is placed on the upper end of the cover, and finally the substrate and cover are bonded by bonding equipment, and the UV glue is cured by light.

[0066] The structural formulas of HT, P-dopant, Prime, Dopant, HB, ET, and CPL used in the device embodiment 1 are as follows:

[0067] Referring to the method provided in the above device embodiment 1, the corresponding compounds in Table 2 were selected to replace compound 1, and the main material of the light-emitting layer was evaporated to prepare the corresponding organic electroluminescent devices, which were respectively recorded as device embodiments 2-38.

[0068] Device Comparison Examples 1-9: Device Comparative Examples 1-9 refer to the preparation method of the above device embodiment 1, and the comparative compound ai is used to replace the host material (compound 1) of the light-emitting layer in the above device embodiment 1 for evaporation, which are respectively recorded as device comparative examples 1-9, wherein the chemical structure of the comparative compound ai is as follows:

[0069] The driving voltage, BI and life of the organic electroluminescent devices obtained from the device embodiments 1-38 and the device comparative examples 1-9 were characterized at a brightness of 1000 (nits). The test results are shown in Table 2 below: Table 2 Test results of organic electroluminescent devices

[0070]

[0071] Those skilled in the art will know that in blue top-emitting devices, the luminous efficiency is greatly affected by chromaticity. Therefore, the influence of chromaticity on efficiency is taken into account, and the ratio of luminous efficiency to CIEy is defined as BI value, that is, BI = (cd / A) / CIEy. In the test, the CIEy value is adjusted in the range of 0.042-0.044.

[0072] It can be seen from Table 2 that, compared with the devices prepared using the comparative compounds 1-9, the organic electroluminescent device embodiments 1-38 prepared using the luminescent layer main material provided by the present invention can improve the luminous efficiency and lifespan while maintaining a low driving voltage.

[0073]

[0074] Compounds a, b and compounds 14, 1 are parallel comparative examples, the difference being that there is no deuteration on a and b in the comparative compounds, while the 1-position of the benzonaphthofuran group in compounds 14 and 1 of the present invention is connected to a deuterated anthracene group and a deuterated phenyl-naphthyl group, a deuterated anthracene group and a deuterated phenyl group, respectively. D has lower activity than H, and the CD bond is more stable than the CH bond, and the bond has a lower vibration frequency, which can increase the rigidity of the molecule and reduce the rotation and distortion of the molecule, which makes the compound less likely to decompose at high temperatures, thereby improving the thermal stability of the material, so that the material can still maintain good performance under high temperature operation, thereby extending the service life of the device. In addition, deuteration reduces non-radiative transitions and can improve the luminous efficiency of the device.

[0075] Since the non-radiative transition of the compound on the anthracene group is reduced, the structure is more stable, which is conducive to improving the life and efficiency of the material after being used in the device. Further introduction of aromatic groups can effectively extend the conjugated system and improve the luminous efficiency. The HOMO energy level of aromatic groups is usually higher and the LUMO energy level is usually lower, which makes the energy gap (HOMO-LUMO energy difference) of aromatic groups larger, and the electron transition is not easy to be too fast, thus having higher stability.

[0076]

[0077] Compounds e, f and compounds 20, 225 are parallel comparative examples, the difference between them is that the anthracene group in the comparative compounds e and f is connected to a deuterated heteroaryl group (deuterated phenyl-dibenzofuran group and deuterated dibenzofuran group respectively), while the anthracene group in the present compounds 20 and 225 is connected to a deuterated aryl group (deuterated phenyl-9,9-dimethylfluorene and deuterated 9,9-dimethylfluorene respectively). The fluorene group structure has a high fluorescence quantum efficiency. After deuteration, the probability of non-radiative transition can be further reduced, thereby improving the fluorescence quantum efficiency. In addition, the HOMO and LUMO energy levels of the fluorene group structure are moderate, which can match well with other functional layers in the device, promote effective carrier injection and transmission, and thus improve the luminescence efficiency of the material device.

[0078] The above is only a preferred specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes according to the technical solution and concept of the present application within the technical scope disclosed in the present application, which should be covered by the protection scope of the present application.

Claims

1. A blue light host material based on benzonaphthofuranyl and anthracene, characterized in that: The blue light host material has a general structural formula shown in Chemical Formula I: ， Wherein, Ar is independently selected from phenyl, and the position of the phenyl ring on the dibenzofuran group is 1, 2, 2, 3 or 3, 4, and the connection position is as follows: ； R1 is independently selected from substituted or unsubstituted C6-C 30 Aryl, substituted or unsubstituted C2-C 30 Heteroaryl, or a combination of the above aryl and heteroaryl, wherein the heteroatom in the heteroaryl contains at least one or more of O, S, N, Si, and Se; R2 is independently selected from C6-C 30 Aryl.

2. The blue light host material according to claim 1, characterized in that: The structure of the chemical formula I includes chemical formula I-A, chemical formula I-B, and chemical formula I-C: 。 3. The blue light host material according to claim 1, characterized in that: R1 is independently selected from substituted or unsubstituted C6-C 18 Aryl, substituted or unsubstituted C5-C 24 Heteroaryl, or a combination of the above aryl and heteroaryl, wherein the heteroatom in the heteroaryl contains at least one or more of O, S, N, Si, and Se.

4. The blue light host material according to claim 1, characterized in that: R2 is independently selected from C6-C 18 Aryl.

5. The blue light host material according to claim 1, characterized in that: Chemical formula I has the following structure: 。 6. The blue light host material according to claim 1, characterized in that: R1 is independently selected from the following groups or any combination thereof: ， Wherein, R3 represents hydrogen or unsubstituted C1-C6 alkyl.

7. The blue light host material according to claim 1, characterized in that: R2 is independently selected from the following groups or any combination thereof: ， R4-R 12 Each is independently selected from hydrogen, deuterium, and C1-C6 alkyl; n4 is each independently selected from 0, 1, 2, 3, 4, 5; n5 and n8 are each independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9; n6、n 11 Each is independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13; n7 and n9 are each independently selected from 0, 1, 2, 3, 4, 5, 6, and 7; n 10 、n 12 Each is independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11.

8. The blue light host material according to claim 1, characterized in that: The "substituted" group in the substituted or unsubstituted is selected from C1-C 10 alkyl; preferably one or more of methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylbutyl, 1-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, 1-methylhexyl, cyclopentane and cyclohexane.

9. The blue light host material according to claim 1, characterized in that: The blue light host material is selected from any one of the compounds shown in the following structural formulas: 。 10. Use of the blue light-emitting host material based on benzonaphthofuranyl and anthracene according to any one of claims 1 to 9 in an organic electroluminescent device.

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