Blue light host material, preparation method and organic electroluminescent device

Abstract

The invention belongs to the field of organic electroluminescent materials, and discloses a blue light host material, a preparation method and an organic electroluminescent device. The structure of the blue light host material is as shown in a chemical formula I: # imgabs0 #. After the blue light host material provided by the invention is applied to the organic electroluminescent device, the luminous efficiency of the photoelectric device is improved and the service life of the photoelectric device is prolonged while low driving voltage is maintained.

Description

Technical Field

[0001] The invention belongs to the field of organic electroluminescent materials, and in particular relates to a blue light main body material, a preparation method and an organic electroluminescent device. Background Art

[0002] The diversity and synthesizability of organic electroluminescent materials have laid a solid foundation for the realization of large-area new display devices. For luminescent materials, efficient red and green light have been continuously developed and are relatively mature, but blue light materials have great deficiencies in efficiency, color purity and lifespan, and the synthesis of efficient blue light materials still faces huge challenges.

[0003] Among the numerous luminescent matrix materials, anthracene emits pure blue light. Due to its large planar conjugated structure, it has the advantages of high fluorescence quantum efficiency, strong carrier mobility and charge injection ability, and high thermal stability, making it a hot topic in the field of organic optoelectronics. However, it is precisely because of this large planar configuration that molecules are very likely to form strong π-π stacking, which reduces the efficiency of the blue light material with excellent performance, red-shifts the emission wavelength, and reduces the color purity, which limits its application in solid-state luminescence. In order to solve this problem, it is necessary to modify its molecules and introduce large substituents on its periphery to increase the distance between chromophores, thereby inhibiting the stacking of molecules and improving the luminescence performance of the material. However, when large substituents are introduced on its periphery, the distance between molecules will be increased, and the carrier transport performance between molecules will be weakened, which will reduce the performance of the device to a certain extent.

[0004] Therefore, designing and finding a stable and efficient compound as a new type of organic electroluminescent material to overcome its shortcomings in practical applications is the focus and future research and development trend in organic electroluminescent device material research. Summary of the invention

[0005] In view of this, and in view of the deficiencies in the prior art, the present invention discloses a blue light host material, a preparation method and an organic electroluminescent device.

[0006] It should be noted that the present invention provides a compound that can be used as a blue light main material in a light-emitting layer, with a rigid benzonaphthofuran group and anthracene group as the main structure, so that the material has good thermal stability and film-forming properties, and the introduction of a deuterated aromatic or heteroaromatic group at the 4-position of the benzonaphthofuran group can effectively extend the conjugated system, improve the fluorescence quantum efficiency, and enhance the stability of the material, so that the material device maintains a low driving voltage, while having a high luminous efficiency and service life.

[0007] In order to achieve the above objectives, the first objective of the present invention is to provide a blue light host material. The following technical scheme is adopted:

[0008] A blue light host material, the blue light host material has a general structural formula of Chemical Formula I:

[0009] ;

[0010] in,

[0011] R1 is selected from a C6-C30 aryl group fully or partially substituted by deuterium, a C2-C30 heteroaryl group fully or partially substituted by deuterium, or a combination of the above aryl groups and heteroaryl groups, wherein the heteroatom in the heteroaryl group contains at least one of O, S, N, Si, and Se;

[0012] R2 is selected from C6-C30 aryl groups which are unsubstituted or fully or partially substituted with deuterium, C2-C30 heteroaryl groups which are unsubstituted or fully or partially substituted with deuterium, or a combination of the above aryl groups and heteroaryl groups, wherein the heteroatom in the heteroaryl group contains at least one of O, S, N, Si, and Se.

[0013] Furthermore, the structure of the blue light host material is specifically as follows:

[0014] .

[0015] Further, R1 is selected from a C6-C18 aryl group fully or partially substituted by deuterium, a C5-C24 heteroaryl group fully or partially substituted by deuterium, or a combination of the above aryl groups and heteroaryl groups, wherein the heteroatom in the heteroaryl group contains at least one of O, S, N, Si, and Se;

[0016] R2 is selected from C6-C18 aryl groups which are unsubstituted or fully or partially substituted with deuterium, C5-C24 heteroaryl groups which are unsubstituted or fully or partially substituted with deuterium, or a combination of the above aryl groups and heteroaryl groups, wherein the heteroatom in the heteroaryl group contains at least one of O, S, N, Si, and Se.

[0017] Furthermore, R1 is selected from the following groups and any combination thereof:

[0018] ;

[0019] Wherein, * represents a connection point, and R3 represents deuterium substitution, which replaces all or part of the hydrogen on the group.

[0020] Furthermore, R2 is selected from the following groups and any combination thereof:

[0021] , * indicates a connection point; where

[0022] R4-R16 are each independently selected from hydrogen and deuterium;

[0023] n4、n 11 Each is independently selected from 0, 1, 2, 3, 4, 5;

[0024] n5 and n8 are each independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9;

[0025] n6、n 14 Each is independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13;

[0026] n7 and n9 are each independently selected from 0, 1, 2, 3, 4, 5, 6, and 7;

[0027] n 10 、n 16 Each is independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8;

[0028] n 12 Independently selected from 0, 1, 2, 3, 4;

[0029] n 13 、n 15 Each is independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11.

[0030] In the above technical solution, the blue light host material is selected from any one of the following compounds:

[0031] .

[0032] The second object of the present invention is to provide a method for preparing the blue light host material as described above.

[0033] 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.

[0034] ;

[0035] In the above formula, R1 and R2 are as defined in the above chemical formula I, Hal1 is independently selected from chlorine or bromine, and X represents or .

[0036] In particular, for complex raw materials that have not been disclosed before, the classic Suzuki coupling reaction is used for synthesis and applied to the present invention.

[0037] Specifically, the preparation method is as follows:

[0038] Step 1 specifically includes the following processes:

[0039] 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 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.

[0040] Step 2 specifically includes the following processes:

[0041] Add intermediate 1 (1.0 eq), diboronic acid pinacol ester (1.0-2.0 eq) and potassium acetate (2.0-4.0 eq) into a three-necked 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, cool down, 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 with a mixed solution of dichloromethane and petroleum ether (V:V=1:3-1:10) to obtain intermediate 2.

[0042] Step 3 specifically includes the following processes:

[0043] Add intermediate 2 (1.0 eq) and raw material C (1.0-1.3 eq) to a reaction flask, then add a mixed solution of toluene, ethanol and water (V:V:V = 3:1:1), add tetrakis(triphenylphosphine)palladium (0.01-0.03 eq) and potassium carbonate (2.0-4.0 eq) or palladium acetate (0.02-0.06 eq), X-Phos (0.1-0.3 eq) and cesium carbonate (2.0-4.0 eq) under nitrogen protection, raise the temperature to 85°C-95°C, and reflux for 3-20 hours; detect the reaction by thin layer chromatography, after the reaction is completed, cool down, 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, and purify by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:3-1:10) to obtain chemical formula I.

[0044] The third object of the present invention is to provide an organic electroluminescent device, which comprises the blue light host material.

[0045] Specifically, the organic electroluminescent device comprises a first electrode, a second electrode and at least one organic thin film layer arranged between the first electrode and the second electrode; the organic thin film layer comprises the blue light host material as described above.

[0046] Furthermore, the blue light host material is used as a host material of a light-emitting layer of an organic electroluminescent device.

[0047] Compared with the prior art, the present invention provides a blue light host material, a preparation method and an organic electroluminescent device, which have the following excellent effects:

[0048] The compound of the present invention effectively exhibits the characteristics of a blue light host material, with a rigid benzonaphthofuran group and anthracene group as the parent core, and has good thermal stability, low driving voltage, excellent luminous efficiency and service life. Specifically,

[0049] 1) Anthracene has a 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 anthracene is relatively stable and can withstand high temperatures, making it difficult to change its structure during the evaporation process, thereby improving the service life of its devices. In addition, anthracene also has a wide bandgap, which makes it have strong absorption and emission capabilities in the blue light region. The introduction of end-capping groups on the anthracene can further adjust the optical properties of the material and effectively adjust the performance of the device.

[0050] 2) The introduction of rigid benzonaphthofuran groups helps improve the thermal stability of the material, thereby enhancing the service life of the device. The fragments of benzonaphthofuran groups containing highly electronegative oxygen atoms can effectively improve the luminescence efficiency of blue light devices.

[0051] 3) Introducing a deuterated substituent (deuterated aryl or deuterated heteroaryl) at the 4-position of the benzonaphthofuran group (the site adjacent to the oxygen atom of the benzene ring) can effectively extend the conjugated system, enhance the conjugated effect, and effectively improve the fluorescence quantum efficiency. At the same time, it avoids the localization of carrier migration and increases the migration rate, thereby reducing the voltage and improving the luminescence efficiency of the device. At the same time, the deuterated substituent on the benzonaphthofuran group balances the molecular structure while making it have higher thermal stability and film-forming properties when evaporating the device, which is beneficial to improving the life of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] 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.

[0053] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of compound 1 provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0054] 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.

[0055] The invention specifically discloses a blue light main body material, a preparation method and an organic electroluminescent device.

[0056] 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.

[0057] The features and performance of the present invention will be further described in detail below with reference to the embodiments.

[0058] Example 1

[0059]

[0060] The raw material A-1 is prior art and is directly used in the synthesis reaction.

[0061] Raw material A-1 (1.0 eq, CAS number: 3058162-50-5), raw material B-1 (1.0 eq, CAS number: 1609386-55-1) 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 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: 81.8%).

[0062] The obtained compound 1 was tested and analyzed, and the results were as follows:

[0063] HPLC purity: >99.8%.

[0064] Mass spectrometry test: The model is Waters XEVO TQD mass spectrometer, using ESI source.

[0065] Test value (ESI, m / Z): [M+H] + ):551.49.

[0066] Elemental Analysis:

[0067] Calculated values: C, 91.44; H, 5.66; O, 2.90;

[0068] Test values: C, 91.18; H, 5.81; O, 3.07.

[0069] H NMR spectrum: Figure 1 (Compound 1) shown.

[0070] Example 2

[0071]

[0072] Step 1 specifically includes the following processes:

[0073] Raw material A-152 (1.0 eq, CAS number: 1489259-11-1), raw material B-152 (1.1 eq, CAS number: 2660005-48-9) 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 (0.01 eq) was added under nitrogen protection. The temperature was raised to 95°C and refluxed for 6 hours. The reaction was detected by thin layer chromatography. After the reaction was completed, the temperature was 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 intermediate 1 was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:5) to obtain intermediate 1 (yield: 75.4%).

[0074] Step 2 specifically includes the following processes:

[0075] In a three-necked flask, intermediate 1 (1.0 eq), pinacol diboron (1.5 eq) and potassium acetate (2.0 eq) were added, followed by 1,4-dioxane. Tris(dibenzylideneacetone)dipalladium (0.02 eq) and X-Phos (0.1 eq) were added under nitrogen protection, the temperature was raised to 120°C, and the reaction was refluxed for 14 hours. 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, dichloromethane and water were added for extraction and separation. The organic phase was retained and concentrated. The intermediate 2 (yield: 73.1%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (V:V=1:4) to obtain the intermediate 2 (yield: 73.1%).

[0076] Step 3 specifically includes the following processes:

[0077] Intermediate 2 (1.0 eq) and raw material C-152 (1.0 eq, CAS number: 2376121-30-9) were added to the reaction flask, followed by a mixed solution of toluene, ethanol and water (V:V:V = 3:1:1). Palladium acetate (0.05 eq), X-Phos (0.1 eq) and cesium carbonate (3.0 eq) were added under nitrogen protection, and the temperature was raised to 95°C, and the reaction was refluxed for 9 hours. 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, 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 152 (yield: 80.7%).

[0078] The obtained compound 152 was tested and analyzed, and the results were as follows:

[0079] HPLC purity: >99.7%.

[0080] Mass spectrometry test: The model is Waters XEVO TQD mass spectrometer, using ESI source.

[0081] Test value (ESI, m / Z): [M+H] + ):721.56

[0082] Calculated values: C, 89.85; H, 5.72; O, 4.43;

[0083] Test values: C, 89.60; H, 5.88; O, 4.59.

[0084] Embodiment 3-49

[0085] 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.

[0086] Table 1 Mass spectrometry test values ​​of Examples 3-49

[0087]

[0088] In addition, other compounds of the present invention can be obtained by referring to the preparation methods of the above-mentioned embodiments, so they are not listed one by one here.

[0089] Device Example 1: Preparation of organic electroluminescent device

[0090] The structure of the prepared OLED device is: ITO anode / HIL / HTL / Prime / EML / HBL / ETL / EIL / cathode / CPL.

[0091] a. ITO anode: The ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 1500Å was cleaned twice in distilled water, ultrasonically washed for 30 minutes, and then repeatedly cleaned twice with distilled water, ultrasonically washed for 10 minutes. After washing, it was ultrasonically washed 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.

[0092] b. HIL (hole injection layer): Hole injection layer materials HT and P-dopant were vacuum evaporated at an evaporation rate of 1Å / s, and their chemical formulas are shown below; the evaporation rate ratio of HT and P-dopant was 97:3, and the thickness was 10nm.

[0093] c. HTL (hole transport layer): 130nm HT was vacuum-deposited on the hole injection layer at a deposition rate of 1.5Å / s as the hole transport layer.

[0094] d. Prime (luminescence auxiliary layer): 5 nm of Prime was vacuum-deposited on the hole transport layer at a deposition rate of 0.5 Å / s as a luminescence auxiliary layer.

[0095] e. EML (light-emitting layer): At a deposition rate of 1Å / s, the main material (Compound 1 provided in the above embodiment) and the dopant material (Dopant) are vacuum-deposited on the light-emitting auxiliary layer as a light-emitting layer, with a total thickness of 30nm, wherein the deposition rate ratio of the main compound to the dopant compound is 98:2.

[0096] f. HBL (hole blocking layer): HB with a thickness of 5 nm was vacuum-deposited on the light-emitting layer at a deposition rate of 0.5 Å / s as a hole blocking layer.

[0097] g. ETL (electron transport layer): ET and Liq with a thickness of 30 nm were vacuum-deposited on the hole blocking layer at a deposition rate of 1 Å / s, where the deposition rate ratio of ET to Liq was 50:50.

[0098] h. EIL (electron injection layer): A Yb film with a thickness of 1 nm is vacuum evaporated on the electron transport layer at a deposition rate of 0.5 Å / s to form an electron injection layer.

[0099] i. Cathode: Magnesium and silver with a thickness of 13 nm were vacuum evaporated on the electron injection layer at a deposition rate ratio of 1Å / s. The deposition rate ratio of magnesium to silver was 1:9 to obtain a cathode.

[0100] 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.

[0101] 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.

[0102] The structural formulas of HT, P-dopant, Prime, Dopant, HB, ET, and CPL used in the device embodiment 1 are as follows:

[0103] .

[0104] Device Example 2-49:

[0105] 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 2-49.

[0106] Device Comparison Examples 1-10:

[0107] Device Comparative Examples 1-10 Referring to the method provided in the above device embodiment 1, compound aj is used to replace the host material (compound 1) of the light-emitting layer in the above device embodiment 1 for evaporation, and are respectively recorded as device comparative examples 1-10, wherein the chemical structure of compound aj is as follows:

[0108] .

[0109] The driving voltage, BI and life of the organic electroluminescent devices obtained from the device embodiments 1-49 and the device comparative examples 1-10 were characterized at a brightness of 1000 (nits). The test results are shown in Table 2 below:

[0110] Table 2 Device test results

[0111]

[0112] Those skilled in the art 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.

[0113] It can be seen from Table 2 that, compared with the device comparative examples 1-10 prepared using the compound aj, the luminous efficiency and life of the organic electroluminescent device embodiments 1-49 prepared using the luminescent layer main material provided by the present invention can be improved while maintaining a low driving voltage.

[0114]

[0115] Compounds b, c and compounds 32, 123 are parallel comparative examples, respectively, the difference being that the 4-position of the benzonaphthofuran group in the comparative compound is connected to an unsubstituted biphenyl group and an unsubstituted phenyl group, respectively, while the 4-position of the benzonaphthofuran group in compounds 32 and 123 of the present invention is connected to a deuterated biphenyl group and a deuterated phenyl group, respectively, the atomic mass of the deuterium atom is about twice that of the hydrogen atom, the vibration frequency of the bond is lower, and the rigidity of the molecule is increased, and the rotation and distortion of the molecule are reduced, 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 the luminous efficiency of the device can be improved.

[0116]

[0117] Compounds e and f and compounds 1 and 14 are parallel comparative examples, respectively. The difference between them is that the deuterated benzene ring in compounds e and f is connected to the 3-position of the benzonaphthofuran group, while the deuterated benzene ring in compounds 1 and 14 of the present invention is connected to the 4-position of the benzonaphthofuran group (adjacent to the oxygen atom), which can enhance the stability of the overall structure and thus extend the service life of the device.

[0118] 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 blue light host material, characterized in that: The structure of the blue light host material is shown in Chemical Formula I: ； in, R1 is selected from a C6-C30 aryl group fully or partially substituted by deuterium, a C2-C30 heteroaryl group fully or partially substituted by deuterium, or a combination of the above aryl groups and heteroaryl groups, wherein the heteroatom in the heteroaryl group contains at least one of O, S, N, Si, and Se; R2 is selected from C6-C30 aryl groups which are unsubstituted or fully or partially substituted with deuterium, C2-C30 heteroaryl groups which are unsubstituted or fully or partially substituted with deuterium, or a combination of the above aryl groups and heteroaryl groups, wherein the heteroatom in the heteroaryl group contains at least one of O, S, N, Si, and Se.

2. The blue light host material according to claim 1, characterized in that: The structure of the blue light host material is specifically as follows: 。 3. The blue light host material according to claim 1 or 2, characterized in that: R1 is selected from a C6-C18 aryl group fully or partially substituted by deuterium, a C5-C24 heteroaryl group fully or partially substituted by deuterium, or a combination of the above aryl groups and heteroaryl groups, wherein the heteroatom in the heteroaryl group contains at least one of O, S, N, Si, and Se; R2 is selected from C6-C18 aryl groups which are unsubstituted or fully or partially substituted with deuterium, C5-C24 heteroaryl groups which are unsubstituted or fully or partially substituted with deuterium, or a combination of the above aryl groups and heteroaryl groups, wherein the heteroatom in the heteroaryl group contains at least one of O, S, N, Si, and Se.

4. The blue light host material according to claim 3, characterized in that: R1 is selected from the following groups and any combination thereof: ； Wherein, * represents a connection point, and R3 represents deuterium substitution, which replaces all or part of the hydrogen on the group.

5. The blue light host material according to claim 3, characterized in that: R2 is selected from the following groups and any combination thereof: ， * indicates a connection point; where R4-R 16 are each independently selected from hydrogen and deuterium; n4、n 11 Each is 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 14 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 16 Each is independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8; n 12 Independently selected from 0, 1, 2, 3, 4; n 13 、n 15 Each is independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11.

6. The blue light host material according to claim 1, characterized in that: The structure of the blue light host material includes but is not limited to any one of the following compounds: 。 7. A method for preparing a blue light host material as claimed in claim 1, characterized in that: The method operates as follows: Step 1 specifically includes the following processes: 1.0 eq of raw material A, 1.0-1.3 eq of raw material B and 2.0-4.0 eq of potassium carbonate were added to a reaction flask, followed by a mixed solution of toluene, ethanol and water in a volume ratio of 3:1:1, and 0.01-0.03 eq of tetrakis(triphenylphosphine)palladium was added under nitrogen protection, and 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, and after the reaction was completed, the temperature was lowered, and diatomaceous earth was used for filtering to remove salt and catalyst, and the filtrate was cooled to room temperature, and then dichloromethane and water were added for extraction and separation, and the organic phase was retained and concentrated, and the intermediate 1 was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether in a volume ratio of 1:3-1:10; Step 2 Specific The process includes: Add 1.0eq of intermediate 1, 1.0-2.0eq of bipyraclostrobin and 2.0-4.0eq of potassium acetate to a three-necked flask, then add 1,4-dioxane, add 0.02-0.10eq of tris(dibenzylideneacetone)dipalladium and 0.1-0.2eq of X-Phos 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, cool down, 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 in a volume ratio of 1:3-1:10 to obtain intermediate 2; Step 3 Specific The process includes: Add 1.0eq of intermediate 2 and 1.0-1.3eq of raw material C to a reaction flask, then add a mixed solution of toluene, ethanol and water in a volume ratio of 3:1:1, add 0.01-0.03eq of tetrakis(triphenylphosphine)palladium and 2.0-4.0eq of potassium carbonate or 0.02-0.06eq of palladium acetate, 0.1-0.3eq of X-Phos and 2.0-4.0eq of cesium carbonate under nitrogen protection, heat to 85°C-95°C, and reflux for 3-20h; detect the reaction by thin layer chromatography, after the reaction is completed, cool, 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 in a volume ratio of 1:3-1:10 to obtain chemical formula I; The specific synthetic route is as follows: ； In the above formula, R1 and R2 are as defined in the above chemical formula I, Hal1 is independently selected from chlorine or bromine, and X represents or .

8. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises the blue light host material as claimed in claim 1.

9. The organic electroluminescent device according to claim 8, characterized in that: The organic electroluminescent device comprises a first electrode, a second electrode and at least one organic thin film layer arranged between the first electrode and the second electrode; the organic thin film layer comprises the blue light host material.

10. The organic electroluminescent device according to claim 9, characterized in that: The blue light host material is used as the host material of the light-emitting layer of the organic electroluminescent device.

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