A benzanthracene-based organic electroluminescent compound and a double-emitting-layer organic electroluminescent device comprising the same

Abstract

The present application relates to the technical field of organic electroluminescent material, and specifically discloses a benzanthracene-based organic electroluminescent compound and a double-light-emitting-layer organic electroluminescent device containing the same. The structural general formula of the benzanthracene-based organic electroluminescent compound is shown as formula I, Ar1 is selected from or ; ring A represents a benzene ring or a naphthalene ring; Ar2 is selected from a substituted or unsubstituted non-fused aryl group with 6-20 carbon atoms or a substituted or unsubstituted fused aryl group with 10-30 carbon atoms; any hydrogen in formula I can be independently substituted by deuterium. The present application can finely control the SOP characteristics of the molecule, realize interlayer polarization matching, and simultaneously has excellent carrier transport capacity and exciton confinement capacity by reasonably designing the substituent type of the benzanthracene-based material, especially suitable for a blue OLED device with a double-light-emitting-layer structure, and has low driving voltage and high efficiency.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescent materials technology, and more particularly to a benzanthracene-based organic electroluminescent compound and a double-emitting-layer organic electroluminescent device containing the same. Background Technology

[0002] Organic light-emitting diodes (OLEDs) have attracted much attention in the display and lighting fields due to their advantages such as self-illumination, wide viewing angle, fast response speed, and flexibility. Among them, blue OLEDs, as a key component of full-color displays, directly determine the device's color reproduction capability and energy utilization efficiency.

[0003] Specifically, most existing blue OLEDs are fabricated using vacuum evaporation, where the host material is prone to exciton quenching in a high-concentration exciton environment, leading to a significant roll-off in device efficiency. More critically, during vacuum evaporation, some polar organic molecules with permanent dipole moments undergo spontaneous orientation polarization (SOP). This microscopic molecular orientation behavior significantly affects the electrostatic potential distribution within the film, thereby altering the energy level arrangement and carrier injection between adjacent functional layers. However, current mainstream blue OLED host material design systems often neglect the systematic regulation of the SOP effect. Existing technologies typically struggle to precisely balance the relationship between dipole polarization intensity and carrier injection efficiency at the molecular level: excessive polarization leads to carrier aggregation and quenching, increasing power consumption; insufficient polarization hinders effective carrier injection and transport, and makes effective exciton confinement difficult. The existing technology has difficulty in accurately balancing polarization intensity and carrier injection efficiency, making it difficult to achieve both the low voltage advantage and high efficiency characteristics of the device, which has become a bottleneck hindering the breakthrough of blue OLED performance.

[0004] Therefore, developing a novel host material that can precisely control the molecular SOP properties, achieve interlayer polarization matching, and possess both excellent carrier transport and exciton confinement capabilities, especially a novel compound suitable for dual-emitting-layer structures, is of great practical significance for improving the overall performance of blue OLEDs. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a benzene-anthracene-based organic electroluminescent compound and a double-emitting-layer organic electroluminescent device containing the same. By rationally designing the substituent types of the benzene-anthracene-based material, interfacial charge accumulation and exciton-polariton quenching are effectively suppressed, enabling the blue OLED device to combine low driving voltage with high efficiency.

[0006] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows: In a first aspect, the present invention provides a benzanthracene-based organic electroluminescent compound, the general structural formula of which is shown in Formula I. I In formula I, Ar1 is selected from or Ring A represents a benzene ring or a naphthalene ring; Ar2 is selected from substituted or unsubstituted non-fused aryl groups with 6 to 20 carbon atoms, and substituted or unsubstituted fused aryl groups with 10 to 30 carbon atoms; In Formula I, any hydrogen atom can be independently replaced by deuterium.

[0007] Preferably, Ar1 is selected from the following structures, whether deuterated or non-deuterated: , , , or .

[0008] More preferably, Ar1 is selected from the following structures, whether deuterated or non-deuterated: , , or .

[0009] Preferably, Ar1 is selected from the following structures, whether deuterated or non-deuterated: .

[0010] More preferably, Ar1 is selected from the following structures, whether deuterated or non-deuterated: .

[0011] Preferably, the non-fused aryl group is selected from phenyl or biphenyl.

[0012] Preferably, the fused aryl group is selected from naphthyl, phenanthryl or pyrene.

[0013] Preferably, Ar2 is selected from substituted or unsubstituted phenyl, biphenyl, naphthyl, phenanthryl or pyrene; when Ar2 has a substituent, the substituent is deuterium or phenyl.

[0014] More preferably, Ar2 is selected from phenyl, biphenyl, naphthyl, phenyl-substituted naphthyl, phenanthryl or pyrene, and any one of the hydrogen atoms in Ar2 can be independently substituted by deuterium.

[0015] More preferably, Ar2 is selected from the following structures, whether deuterated or non-deuterated: .

[0016] More preferably, the structure of the benzanthracene-based organoelectroluminescent compound is selected from any one of the following structural formulas: In the above structural formula of the benzanthracene-type organic electroluminescent compound, any hydrogen atom can be independently replaced by deuterium; Dn represents the substitution of n hydrogen atoms by deuterium in the structural formula, where n is a positive integer and takes values ​​from 1 to the maximum deuterium algebra.

[0017] In a second aspect, the present invention provides a dual-emitting-layer organic electroluminescent device, comprising a first emitting layer and a second emitting layer stacked adjacent to each other; the first emitting layer is located near the hole transport side, and the second emitting layer is located near the electron transport side; the raw material of the first emitting layer includes the aforementioned benzene-anthracene organic electroluminescent compound.

[0018] Preferably, the dual-emitting-layer organic electroluminescent device comprises, from bottom to top, an anode, a hole transport region, an electron blocking layer, a first emitting layer, a second emitting layer, a hole blocking layer, an electron transport region, and a cathode, which are sequentially disposed on a substrate; wherein, the raw material of the first emitting layer includes a first host material and a first guest material, and the first host material includes one or more of the benzene-anthracene-based organic electroluminescent compounds.

[0019] More preferably, the hole transport region includes a hole injection layer and a hole transport layer.

[0020] More preferably, the electron transport region includes an electron transport layer and an electron injection layer.

[0021] In this invention, the anode uses a commonly used anode material in the art, such as ITO, Ag, or their multilayer structures. The hole injection layer uses a commonly used hole injection material in the art, and is doped with F4TCNQ, HATCN, NDP-9, etc. The hole transport layer uses a commonly used hole transport material in the art. The first light-emitting layer uses the compound provided in this invention as the first host material, combined with a commonly used guest compound in the art. The second light-emitting layer uses a commonly used host compound in the art as the second host material, combined with a commonly used guest compound in the art. The electron transport layer uses a commonly used electron transport material in the art. The electron injection layer uses a commonly used electron injection material in the art, such as LiQ, LiF, Yb, etc. The cathode uses a commonly used material in the art, such as metallic Al, Ag, or metal mixtures (Ag-doped Mg, Ag-doped Ca, etc.). The electrode preparation method and the deposition method of each functional layer in this invention are conventional methods in the art, such as vacuum thermal evaporation or inkjet printing, etc., and will not be described in detail here.

[0022] The benzanthracene-based organic electroluminescent compounds provided by this invention are benzanthracene As the parent nucleus (the numbers in the structural formula represent the connection sites between the benzene anthracene parent nucleus and other fragments; the connection sites described below are consistent with this structural formula).

[0023] The organic electroluminescent compound provided by this invention uses benzenexane as the parent nucleus, with a furan group attached to site 4 of the benzenexane parent nucleus and an aryl fragment attached to site 7 of the benzenexane parent nucleus. This effectively suppresses interfacial charge accumulation and exciton-polaron quenching. By attaching a furan group to site 4 of the benzenexane parent nucleus, molecular polarization is achieved, increasing the state of charge (SOP), lowering the carrier injection barrier, and improving carrier injection efficiency, thereby reducing the driving voltage. Furthermore, by attaching a furan group to site 4 of the benzenexane parent nucleus and an aryl fragment to site 7, steric hindrance is used to prevent highly uniform molecular orientation, weakening the polarization effect and preventing excessively high SOP. This results in a compound with a relatively suitable molecular orientation and SOP value, avoiding exciton quenching caused by excessive carrier aggregation at the interface, and effectively suppressing high-concentration exciton quenching while maintaining high EQE stability. The compound provided by this invention effectively suppresses interfacial charge accumulation and exciton-polaron quenching.

[0024] Using the organic electroluminescent compound provided by this invention as the main material of the first luminescent layer of a dual-emitting-layer blue organic electroluminescent device can significantly reduce the device driving voltage and simultaneously improve the device luminous efficiency.

[0025] Compared with the prior art, the benzanthracene-based organic electroluminescent compound and the double-emitting-layer organic electroluminescent device containing the same provided by the present invention have the following significant advantages: (1) Precisely controlling SOP characteristics to break through the efficiency-voltage tradeoff bottleneck: This invention abandons the single substitution mode that easily induces excessive spontaneous orientation polarization (SOP) at the molecular design level, and avoids the problem of dipole moment dissipation caused by excessively long bridging structures. By introducing a furan group with a specific structure at site 4 of the benzene-anthracene core, molecular polarization is effectively induced, significantly improving the SOP strength of the film, optimizing the electrostatic potential distribution at the functional layer interface, thereby greatly reducing the carrier injection barrier and realizing low-voltage drive of the device.

[0026] (2) Suppressing exciton quenching and maintaining high EQE stability: To address the risk of excessive SOP and interface charge accumulation that may result from the introduction of polar groups at site 4, this invention ingeniously constructs a specific aryl structure at site 7 of the parent core. This structure physically restricts the excessive orientation of the molecule through steric hindrance, effectively preventing the runaway growth of SOP intensity and avoiding excessive accumulation of charge carriers at the interface, thereby significantly suppressing the exciton-polaron quenching effect and ensuring that the device maintains excellent external quantum efficiency (EQE) even at high brightness.

[0027] (3) Achieving interlayer polarization matching and improving overall performance: This invention achieves a fine balance between molecular dipole moment and orientation order at the molecular level by synergistically optimizing the "push-pull electron" effect at site 4 and the "steric hindrance regulation" effect at site 7. This unique molecular engineering strategy not only takes into account the efficient injection and transport of charge carriers, but also strengthens the exciton confinement capability and effectively eliminates the phenomenon of interfacial charge accumulation. Ultimately, the dual-emitting-layer device containing this compound successfully combines the excellent performance of low turn-on voltage, high external quantum efficiency and low efficiency roll-off, solving the core problem of existing blue OLEDs that are difficult to balance low power consumption and high efficiency. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the dual-emitting-layer organic electroluminescent device in an embodiment of the present invention; In the figure, 1 represents the substrate, 2 represents the anode, 3 represents the hole injection layer, 4 represents the hole transport layer, 5 represents the electron blocking layer, 6 represents the first light-emitting layer, 7 represents the second light-emitting layer, 8 represents the hole blocking layer, 9 represents the electron transport layer, 10 represents the electron injection layer, 11 represents the cathode, and 12 represents the capping layer. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0030] Terms and Definitions In this invention, the terms "preferred," "further preferred," "more preferred," and "even more preferred" refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this invention.

[0031] "Deuterium" refers to the hydrogen isotope deuterium.

[0032] "Deuteration" refers to the substitution of one or more hydrogen atoms in a group by deuterium.

[0033] Dn indicates that n hydrogen atoms in the structure are replaced by deuterium, where n is a positive integer ranging from 1 to the maximum deuteration algebra. In optional structures containing "Dn", at least one hydrogen atom is replaced by deuterium, and "maximum deuteration algebra" indicates that all hydrogen atoms in the corresponding structure are replaced by deuterium.

[0034] “ "" indicates the connection site with other atoms.

[0035] "The same substituents but different connection sites" means that the substituents have the same structure. For example, when Ar2 is naphthyl, the parent nucleus structure can be connected to the naphthyl at position 1 (α position) and position 2 (β position) through single bonds.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0037] The following are specific examples. Unless otherwise specified, the solvents and reagents used in the examples are all available from conventional reagent suppliers, and the relevant compounds can be prepared by existing processes or conventional processes in the art. Unless otherwise stated, the subsequent synthesis is carried out under a protective gas atmosphere in anhydrous solvents.

[0038] The general formula for synthesizing benzanthracene-based organic electroluminescent compounds is shown below: To better illustrate the present invention, further examples are provided below.

[0039] Synthesis example 1 This synthetic example provides a method for synthesizing a benzene-anthracene-based organic electroluminescent compound (denoted as BH1-1), the chemical equation of which is shown below.

[0040] S1. In a three-necked flask, under nitrogen protection, 125 mL of toluene, 80 mL of ethanol, and 80 mL of water were added. Then, compound H1 (7.68 g, 25 mmol), compound K1 (5.30 g, 25 mmol), potassium carbonate (10.38 g, 75 mmol), and tetraphenylphosphine palladium (0.88 g, 0.75 mmol) were added. The mixture was heated to 80 °C and reacted for 12 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filter cake was dissolved in toluene and then filtered to remove the solid insoluble matter. The mixture was then recrystallized to give compound L1: 7.88 g, yield: 80%, MS (m / z) (M+H): 395.14.

[0041] S2. In a three-necked flask, compound L1 (7.88 g, 20 mmol) was stirred with 200 mL of N,N-dimethylformamide. N-bromosuccinimide (4.28 g, 24 mmol) was added at room temperature, and the mixture was stirred for 8 h. Methanol was added to the reaction solution and the resulting yellow solid was filtered. The solid was recrystallized from toluene and dried under vacuum to give compound A1: 6.63 g, yield: 70%, MS (m / z) (M+H): 473.05.

[0042] S3. In a three-necked flask, under nitrogen protection, add 50 mL of toluene, 25 mL of ethanol, and 25 mL of water. Then add compound A1 (4.73 g, 10 mmol), compound B1 (2.22 g, 10 mmol), potassium carbonate (4.15 g, 30 mmol), and tetraphenylphosphine palladium (0.35 g, 0.30 mmol). Heat to 80 °C and react for 12 h. After the reaction is complete, cool to room temperature, filter, dissolve the filter cake in toluene, filter to remove solid insolubles, and then recrystallize to give compound BH1-1: 3.42 g, yield: 60%, MS (m / z) (M+H): 571.20.

[0043] Synthesis example 2 This synthetic example provides a method for synthesizing a benzene-anthracene-based organic electroluminescent compound (denoted as BH1-2), the chemical equation of which is shown below.

[0044] Compound A2 was prepared using a synthetic method similar to that used in Synthesis Example 1, except that in S1, compound H1 was replaced with an equimolar amount. The remaining conditions are the same as S1~S2 in Synthesis Example 1, and will not be repeated here.

[0045] S3. In a three-necked flask, under nitrogen protection, add 50 mL of toluene, 25 mL of ethanol, and 25 mL of water. Then add compound A2 (4.83 g, 10 mmol), compound B2 (1.22 g, 10 mmol), potassium carbonate (4.15 g, 30 mmol), and tetraphenylphosphine palladium (0.35 g, 0.30 mmol). Heat to 80 °C and react for 12 h. After the reaction is complete, cool to room temperature, filter, and dissolve the filter cake in toluene by heating and then filter to remove the solid insoluble matter. Recrystallize to give compound BH1-2: 2.92 g, yield: 61%, MS (m / z) (M+H): 481.29.

[0046] Synthesis example 3 This synthetic example provides a method for synthesizing a benzene-anthracene-based organic electroluminescent compound (denoted as BH1-3), the chemical equation of which is shown below.

[0047] Compound A3 was prepared using a synthetic method similar to that used in Synthesis Example 1, except that in S1, compound K1 was replaced with an equimolar amount. The remaining conditions are the same as S1~S2 in Synthesis Example 1, and will not be repeated here.

[0048] S3. In a three-necked flask, under nitrogen protection, add 50 mL of toluene, 25 mL of ethanol, and 25 mL of water. Then add compound A3 (4.73 g, 10 mmol), compound B3 (1.71 g, 10 mmol), potassium carbonate (4.15 g, 30 mmol), and tetraphenylphosphine palladium (0.35 g, 0.30 mmol). Heat to 80 °C and react for 12 h. After the reaction is complete, cool to room temperature, filter, dissolve the filter cake in toluene, filter to remove solid insoluble matter, and then recrystallize to give compound BH1-3: 3.17 g, yield: 61%, MS (m / z) (M+H): 521.18.

[0049] Synthesis example 4 This synthetic example provides a method for synthesizing a benzanthracene-based organic electroluminescent compound (denoted as BH1-4), the chemical equation of which is shown below.

[0050] Compound A4 was prepared using a synthetic method similar to that used in Synthesis Example 1, except that in S1, compound K1 was replaced with an equimolar amount. The remaining conditions are the same as S1~S2 in Synthesis Example 1, and will not be repeated here.

[0051] S3. In a three-necked flask, under nitrogen protection, add 50 mL of toluene, 25 mL of ethanol, and 25 mL of water. Then add compound A4 (4.73 g, 10 mmol), compound B4 (1.79 g, 10 mmol), potassium carbonate (4.15 g, 30 mmol), and tetraphenylphosphine palladium (0.35 g, 0.30 mmol). Heat to 80 °C and react for 12 h. After the reaction is complete, cool to room temperature, filter, dissolve the filter cake in toluene, filter to remove solid insoluble matter, and then recrystallize to give compound BH1-4: 4.05 g, yield: 77%, MS (m / z) (M+H): 528.27.

[0052] Synthesis example 5 This synthetic example provides a method for synthesizing a benzene-anthracene-based organic electroluminescent compound (denoted as BH1-5), the chemical equation of which is shown below.

[0053] Compound A5 was prepared using a synthetic method similar to that used in Synthesis Example 1, except that in S1, compound K1 was replaced with an equimolar amount. The remaining conditions are the same as S1~S2 in Synthesis Example 1, and will not be repeated here.

[0054] S3. In a three-necked flask, under nitrogen protection, add 50 mL of toluene, 25 mL of ethanol, and 25 mL of water. Then add compound A5 (4.73 g, 10 mmol), compound B5 (1.98 g, 10 mmol), potassium carbonate (4.15 g, 30 mmol), and tetraphenylphosphine palladium (0.35 g, 0.30 mmol). Heat to 80 °C and react for 12 h. After the reaction is complete, cool to room temperature, filter, and dissolve the filter cake in toluene by heating and then filter to remove the solid insoluble matter. Recrystallize to give compound BH1-5: 3.33 g, yield: 61%, MS (m / z) (M+H): 547.20.

[0055] Synthesis example 6 This synthetic example provides a method for synthesizing a benzene-anthracene-based organic electroluminescent compound (denoted as BH1-6), the chemical equation of which is shown below.

[0056] Compound A6 was prepared using a synthetic method similar to that used in Synthesis Example 1, except that in S1, compound K1 was replaced with an equimolar amount. The remaining conditions are the same as S1~S2 in Synthesis Example 1, and will not be repeated here.

[0057] S3. In a three-necked flask, under nitrogen protection, add 50 mL of toluene, 25 mL of ethanol, and 25 mL of water. Then add compound A6 (5.29 g, 10 mmol), compound B6 (2.46 g, 10 mmol), potassium carbonate (4.15 g, 30 mmol), and tetraphenylphosphine palladium (0.35 g, 0.30 mmol). Heat to 80 °C and react for 12 h. After the reaction is complete, cool to room temperature, filter, and dissolve the filter cake in toluene by heating and then filter to remove the solid insoluble matter. Then recrystallize to give compound BH1-6: 5.00 g, yield: 77%, MS (m / z) (M+H): 651.29.

[0058] Synthesis Example 7 This synthetic example provides a method for synthesizing a benzene-anthracene-based organic electroluminescent compound (denoted as BH1-7), the chemical equation of which is shown below.

[0059] Compound A7 was prepared using a synthetic method similar to that used in Synthesis Example 1, except that in S1, compound K1 was replaced with an equimolar amount. The remaining conditions are the same as S1~S2 in Synthesis Example 1, and will not be repeated here.

[0060] S3. In a three-necked flask, under nitrogen protection, add 50 mL of toluene, 25 mL of ethanol, and 25 mL of water. Then add compound A7 (5.23 g, 10 mmol), compound B7 (2.22 g, 10 mmol), potassium carbonate (4.15 g, 30 mmol), and tetraphenylphosphine palladium (0.35 g, 0.30 mmol). Heat to 80 °C and react for 12 h. After the reaction is complete, cool to room temperature, filter, and dissolve the filter cake in toluene and filter to remove the solid insoluble matter. Then recrystallize to give compound BH1-7: 3.90 g, yield: 63%, MS (m / z) (M+H): 621.21.

[0061] 1 H NMR (500 MHz, DMSO- d 6) δ 8.83 (d, J = 2.4 Hz, 1H), 8.61 – 8.58 (m,1H), 8.48 – 8.45 (m, 1H), 8.41 (d, J = 8.3 Hz, 1H), 8.36 (d, J = 8.0 Hz, 1H), 8.25 (d, J = 8.2 Hz, 1H), 8.19 – 8.09 (m, 4H), 8.07 – 7.86 (m, 9H), 7.81 – 7.77(m, 1H), 7.73 (d, J = 2.3 Hz, 1H), 7.63 – 7.47 (m, 6H), 7.47 – 7.41 (m, 1H). Synthesis example 8 This synthetic example provides a method for synthesizing a benzene-anthracene-based organic electroluminescent compound (denoted as BH1-8), the chemical equation of which is shown below.

[0062] Compound A8 was prepared using a synthetic method similar to that used in Synthesis Example 1, except that in S1, compound K1 was replaced with an equimolar amount. The remaining conditions are the same as S1~S2 in Synthesis Example 1, and will not be repeated here.

[0063] S3. In a three-necked flask, under nitrogen protection, add 50 mL of toluene, 25 mL of ethanol, and 25 mL of water. Then add compound A8 (5.23 g, 10 mmol), compound B8 (1.98 g, 10 mmol), potassium carbonate (4.15 g, 30 mmol), and tetraphenylphosphine palladium (0.35 g, 0.30 mmol). Heat to 80 °C and react for 12 h. After the reaction is complete, cool to room temperature, filter, dissolve the filter cake in toluene, filter to remove solid insoluble matter, and then recrystallize to give compound BH1-8: 3.63 g, yield: 61%, MS (m / z) (M+H): 597.21.

[0064] Synthesis example 9 This synthetic example provides a method for synthesizing a benzene-anthracene-based organic electroluminescent compound (denoted as BH1-9), the chemical equation of which is shown below.

[0065] Compound A9 was prepared using a synthetic method similar to that used in Synthesis Example 1, except that in S1, compound K1 was replaced with an equimolar amount. The remaining conditions are the same as S1~S2 in Synthesis Example 1, and will not be repeated here.

[0066] S3. In a three-necked flask, under nitrogen protection, add 50 mL of toluene, 25 mL of ethanol, and 25 mL of water. Then add compound A9 (5.23 g, 10 mmol), compound B9 (1.98 g, 10 mmol), potassium carbonate (4.15 g, 30 mmol), and tetraphenylphosphine palladium (0.35 g, 0.30 mmol). Heat to 80 °C and react for 12 h. After the reaction is complete, cool to room temperature, filter, and dissolve the filter cake in toluene by heating and then filter to remove the solid insoluble matter. Then recrystallize to give compound BH1-9: 3.75 g, yield: 63%, MS (m / z) (M+H): 597.21.

[0067] Synthesis example 10 This synthetic example provides a method for synthesizing a benzene-anthracene-based organic electroluminescent compound (denoted as BH1-10), the chemical equation of which is shown below.

[0068] Compound A10 was prepared using a synthetic method similar to that used in Synthesis Example 1, except that in S1, compound K1 was replaced with an equimolar amount. The remaining conditions are the same as S1~S2 in Synthesis Example 1, and will not be repeated here.

[0069] S3. In a three-necked flask, under nitrogen protection, add 50 mL of toluene, 25 mL of ethanol, and 25 mL of water. Then add compound A10 (5.32 g, 10 mmol), compound B10 (2.22 g, 10 mmol), potassium carbonate (4.15 g, 30 mmol), and tetraphenylphosphine palladium (0.35 g, 0.30 mmol). Heat to 80 °C and react for 12 h. After the reaction is complete, cool to room temperature, filter, dissolve the filter cake in toluene, filter to remove solid insoluble matter, and then recrystallize to give compound BH1-10: 4.46 g, yield: 71%, MS (m / z) (M+H): 630.32.

[0070] Synthesis example 11 This synthetic example provides a method for synthesizing a benzene-anthracene-based organic electroluminescent compound (denoted as BH1-11), the chemical equation of which is shown below.

[0071] Compound A11 was prepared using a synthetic method similar to that used in Synthesis Example 1, except that in S1, compound K1 was replaced with an equimolar amount. The remaining conditions are the same as S1~S2 in Synthesis Example 1, and will not be repeated here.

[0072] S3. In a three-necked flask, under nitrogen protection, add 50 mL of toluene, 25 mL of ethanol, and 25 mL of water. Then add compound A11 (5.23 g, 10 mmol), compound B11 (2.48 g, 10 mmol), potassium carbonate (4.15 g, 30 mmol), and tetraphenylphosphine palladium (0.35 g, 0.30 mmol). Heat to 80 °C and react for 12 h. After the reaction is complete, cool to room temperature, filter, dissolve the filter cake in toluene, filter to remove solid insoluble matter, and then recrystallize to give compound BH1-11: 5.23 g, yield: 81%, MS (m / z) (M+H): 647.23.

[0073] Synthesis example 12 This synthetic example provides a method for synthesizing a benzene-anthracene-based organic electroluminescent compound (denoted as BH1-12), the chemical equation of which is shown below.

[0074] Compound A12 was prepared using a synthetic method similar to that used in Synthesis Example 1, except that in S1, compound K1 was replaced with an equimolar amount. The remaining conditions are the same as S1~S2 in Synthesis Example 1, and will not be repeated here.

[0075] S3. In a three-necked flask, under nitrogen protection, add 50 mL of toluene, 25 mL of ethanol, and 25 mL of water. Then add compound A12 (4.97 g, 10 mmol), compound B12 (2.48 g, 10 mmol), potassium carbonate (4.15 g, 30 mmol), and tetraphenylphosphine palladium (0.35 g, 0.30 mmol). Heat to 80 °C and react for 12 h. After the reaction is complete, cool to room temperature, filter, dissolve the filter cake in toluene, filter to remove solid insolubles, and then recrystallize to give compound BH1-12: 3.78 g, yield: 61%, MS (m / z) (M+H): 621.21.

[0076] Synthesis example 13 This synthetic example provides a method for synthesizing a benzene-anthracene-based organic electroluminescent compound (denoted as BH1-13), the chemical equation of which is shown below.

[0077] Compound A13 was prepared using a synthetic method similar to that used in Synthesis Example 1, except that in S1, compound K1 was replaced with an equimolar amount. The remaining conditions are the same as S1~S2 in Synthesis Example 1, and will not be repeated here.

[0078] S3. In a three-necked flask, under nitrogen protection, add 50 mL of toluene, 25 mL of ethanol, and 25 mL of water. Then add compound A13 (4.97 g, 10 mmol), compound B13 (2.48 g, 10 mmol), potassium carbonate (4.15 g, 30 mmol), and tetraphenylphosphine palladium (0.35 g, 0.30 mmol). Heat to 80 °C and react for 12 h. After the reaction is complete, cool to room temperature, filter, dissolve the filter cake in toluene, filter to remove solid insolubles, and then recrystallize to give compound BH1-13: 4.58 g, yield: 74%, MS (m / z) (M+H): 621.21.

[0079] Synthesis Example 14 This synthetic example provides a method for synthesizing a benzene-anthracene-based organic electroluminescent compound (denoted as BH1-14), the chemical equation of which is shown below.

[0080] Compound A14 was prepared using a synthetic method similar to that used in Synthesis Example 1, except that in S1, compound K1 was replaced with an equimolar amount. The remaining conditions are the same as S1~S2 in Synthesis Example 1, and will not be repeated here.

[0081] S3. In a three-necked flask, under nitrogen protection, add 50 mL of toluene, 25 mL of ethanol, and 25 mL of water. Then add compound A14 (4.97 g, 10 mmol), compound B14 (2.48 g, 10 mmol), potassium carbonate (4.15 g, 30 mmol), and tetraphenylphosphine palladium (0.35 g, 0.30 mmol). Heat to 80 °C and react for 12 h. After the reaction is complete, cool to room temperature, filter, and dissolve the filter cake in toluene by heating and then filter to remove the solid insoluble matter. Recrystallize to give compound BH1-14: 3.84 g, yield: 62%, MS (m / z) (M+H): 621.21.

[0082] Synthesis Example 15 This synthetic example provides a method for synthesizing a benzene-anthracene-based organic electroluminescent compound (denoted as BH1-15), the chemical equation of which is shown below.

[0083] Compound A15 was prepared using a synthetic method similar to that used in Synthesis Example 1, except that in S1, compound K1 was replaced with an equimolar amount. The remaining conditions are the same as S1~S2 in Synthesis Example 1, and will not be repeated here.

[0084] S3. In a three-necked flask, under nitrogen protection, add 50 mL of toluene, 25 mL of ethanol, and 25 mL of water. Then add compound A15 (4.97 g, 10 mmol), compound B15 (2.46 g, 10 mmol), potassium carbonate (4.15 g, 30 mmol), and tetraphenylphosphine palladium (0.35 g, 0.30 mmol). Heat to 80 °C and react for 12 h. After the reaction is complete, cool to room temperature, filter, dissolve the filter cake in toluene, filter to remove solid insoluble matter, and then recrystallize to give compound BH1-15: 4.83 g, yield: 78%, MS (m / z) (M+H): 621.21.

[0085] The molecular structural formulas of the comparative host compounds DBH1~DBH7 used in this invention are as follows: Verification Experiment 1 To illustrate the beneficial effects of the benzene-anthracene organic electroluminescent compounds provided by this invention, molecular orientation and SOP values ​​of compounds BH1-1 to BH1-15 and comparative compounds DBH1 to DBH7 were tested, and the results are shown in Table 1.

[0086] (1) Molecular orientation of each compound was determined by VASE. Quartz glass or silicon substrates were ultrasonically cleaned with deionized water, acetone, and isopropanol for 15 minutes, dried with nitrogen, and then treated with ultraviolet ozone for 15 minutes. Thin films were prepared by vacuum evaporation, and compounds BH1-1 to BH1-15 and control compounds DBH1 to DBH7 were deposited on the substrates at a rate of 1 A / s. The thin films were tested with light in the spectral range of 300 nm to 800 nm and a step size of 5 nm. The incident angles were set to 50°, 60°, and 70°, and the degree of order (S, dimensionless) of each thin film was calculated. The value of S ranged from -0.5 to 1, where -0.5 represented a completely horizontal arrangement, 0 represented isotropic arrangement, and 1 represented a completely vertical arrangement.

[0087] (2) Place the above thin film samples in a completely dark environment and measure the surface potential of each thin film non-contactly using the Rotary Kelvin Probe Method. Divide the measured surface potential by the film thickness to obtain the SOP value (unit: mV / nm). A SOP value that is too large (greater than 40 mV / nm) indicates that the carrier injection and transport are too fast, leading to carrier accumulation and exciton quenching. A SOP value that is too small (less than 10 mV / nm) indicates that the carrier injection and transport are too slow, leading to voltage rise and reducing the exciton recombination rate.

[0088] Table 1. Molecular orientation and SOP value of each compound As can be seen from the results in Table 1, compared with the comparative compounds, the benzene-anthracene organic electroluminescent compounds provided by the present invention have relatively suitable molecular orientation and SOP value.

[0089] Compared to compound BH1-2 provided in this invention, compounds DBH1 and DBH2, during vacuum evaporation, exhibit significantly increased spontaneous orientation polarization (SOP) due to their smaller intermolecular steric hindrance during film deposition, leading to a highly uniform molecular orientation (Sp approaching -0.5). Excessive SOP can cause polarization mismatch with adjacent functional layers during device operation, resulting in a large accumulation of charge carriers at the emissive layer interface and subsequent severe exciton-polarizer quenching. Compound BH1-2, provided in this invention, combines a furan group at site 4 of the benzenexane core with an aryl group at site 7. The furan group at site 4 polarizes the molecules, increasing SOP, while the aryl group at site 7, through steric hindrance, prevents highly uniform molecular orientation, weakens the polarization effect, and thus prevents excessive SOP, reduces local exciton aggregation and quenching, and improves exciton utilization.

[0090] In the comparative compounds DBH3~DBH7, the furan groups are not directly attached to the benzenexane core, but rather connected via a benzene ring as a bridging group. This bridging structure weakens the inductive effect of oxygen atoms on the core, resulting in a weak overall spontaneous orientation polarization (SOP) of the molecule, making it difficult to effectively reduce the interfacial barrier for carrier injection into the luminescent layer. The benzenexane-based organic electroluminescent compounds provided in this invention have furan groups directly connected to benzenexane, utilizing the electron-deficient effect of oxygen atoms to induce molecular polarization, reducing the carrier injection barrier, increasing the carrier transport rate, and thus improving exciton utilization.

[0091] Example 1 This embodiment provides a dual-emitting-layer organic electroluminescent device (i.e., a blue OLED device), the structure of which is as follows: Figure 1 As shown, from bottom to top, it includes an anode, a hole transport region, an electron blocking layer, a first light-emitting layer, a second light-emitting layer, a hole blocking layer, an electron transport region, and a cathode, which are sequentially disposed on a substrate; wherein, the first light-emitting layer includes a first host material and a first guest material, and the second light-emitting layer includes a second host material and a second guest material.

[0092] The fabrication method of the above-mentioned double-emitting-layer organic electroluminescent device includes the following steps: S100. After patterning the ITO / Ag / ITO substrate to achieve a light-emitting area of ​​3mm × 3mm, perform ultrasonic treatment with water / isopropanol, UV / ozone irradiation, and drying at 100℃. Then, mount the ITO / Ag / ITO substrate on the substrate support of the vacuum deposition apparatus and adjust the pressure to achieve a vacuum rate of 1 × 10⁻⁶. -7 torr.

[0093] S200. On the ITO layer (anode) formed on the substrate, a hole injection layer is formed by vacuum depositing compound HT01 and compound PD01 (mass ratio of compound HT01 to compound PD01 is 97:3) with a thickness of 10 nm.

[0094] S300. On the hole injection layer, a hole transport layer is formed by vacuum deposition of compound HT01 with a thickness of 100 nm.

[0095] S400. On the hole transport layer, an electron blocking layer is formed by vacuum deposition of compound BP01 with a thickness of 5 nm.

[0096] S500, a first host material BH1-1 and a dopant material BD01 (i.e., a first guest material) are co-deposited on an electron blocking layer, with the mass ratio of compound BH1-1 to compound BD01 being 97:3, forming a first light-emitting layer with a film thickness of 5 nm.

[0097] S600, a second host material BH2-01 and a dopant material BD01 (i.e., a second guest material) are co-deposited on the first light-emitting layer, with the mass ratio of compound BH2-01 to compound BD01 being 98:2, to form a second light-emitting layer with a film thickness of 15nm.

[0098] S700, HB01 compound is deposited on the second light-emitting layer to form a hole blocking layer with a thickness of 5 nm.

[0099] S800, on the hole blocking layer, a 30 nm thick compound ET01 and compound LiQ (the mass ratio of compound ET01 to compound LiQ is 1:1) are vacuum deposited to form an electron transport layer.

[0100] S900, on the electron transport layer, a 1 nm thick Yb layer is vacuum deposited to form an electron injection layer.

[0101] S1000, on the electron injection layer, Mg and Ag (Mg to Ag mass ratio of 1:9) are deposited to form a cathode with a thickness of 15 nm.

[0102] S1100: On the cathode, a 50nm thick compound CP01 is deposited to form a capping layer. Then, the substrate after evaporation is encapsulated. A UV adhesive coating process is used to coat the cleaned cover plate with adhesive. The coated cover plate is then moved to the lamination section. The evaporated substrate is placed on the top of the cover plate. Finally, the substrate and cover plate are laminated under the action of a lamination device. At the same time, the UV adhesive is photocured to prepare a top-emitting double-emitting organic electroluminescent device (i.e., blue OLED device).

[0103] Except for the first host material BH1-1, the molecular structural formulas of the compound materials used in each layer of this embodiment are as follows: Examples 2-15 Examples 2-15 provide a dual-emitting-layer organic electroluminescent device, the structure and preparation method of which are similar to those of Example 1, except that the first host material is replaced with compounds BH1-2 to BH1-15 respectively. Other conditions and parameter settings are the same as those in Example 1, and will not be repeated here.

[0104] Comparative Examples 1-7 Comparative Examples 1-7 provide a dual-emitting-layer organic electroluminescent device, the structure and preparation method of which are similar to those of Example 1, except that the first host material is replaced with compounds DBH1-DBH7 respectively. Other conditions and parameter settings are the same as those of Example 1, and will not be repeated here.

[0105] Verification Experiment 2 At J = 10 mA / cm 2 At the specified current density, the driving voltage, luminance, electroluminescent current efficiency (measured in cd / A), and external quantum efficiency (EQE, measured as a percentage) of the dual-emitting-layer organic electroluminescent devices provided in Examples 1-15 and Comparative Examples 1-7 were tested respectively. EQE was calculated as a function of luminescent density from the current / voltage / luminescent density characteristic line (IVL characteristic line) exhibiting Lambertian emission characteristics. The test results are shown in Table 2.

[0106] EQE(%) = (Electroluminescence current efficiency / K(λ)) × 100 In the above formula, K(λ) is the luminous efficacy constant, which is a coefficient related to the emission wavelength.

[0107] The testing instruments and methods used for the above performance tests are as follows: Electroluminescence current efficiency (cd / A) was measured using a PhotoResearch PR-635 spectral scanner.

[0108] Current density and turn-on voltage were tested using a Keithley 2400 digital source meter.

[0109] Table 2 Performance test results of double-emitting-layer organic electroluminescent devices As can be seen from Table 2, compared with the device comparative examples 1 to 7, the device embodiments provided by the present invention have the advantages of higher luminous efficiency and lower driving voltage.

[0110] In Comparative Examples 1 and 2, the first host materials DBH1 and DBH2 have strong spontaneous orientation polarization (SOP). Excessive SOP is prone to polarization mismatch with adjacent functional layers, resulting in a large accumulation of charge carriers at the interface of the light-emitting layer, which triggers exciton-polaron quenching and makes the EQE relatively low.

[0111] In the device comparative examples 3 to 7, the spontaneous orientation polarization (SOP) of the first host material DBH3 to DBH7 is relatively weak, making it difficult to effectively reduce the carrier injection barrier and reduce the exciton recombination probability. Ultimately, this results in a relatively high device driving voltage and a relatively low EQE, which is not conducive to achieving low power consumption of the device.

[0112] In the device embodiments 1 to 15 provided by the present invention, the compounds used have relatively suitable molecular orientation and SOP value, and are used as the main material of the first light-emitting layer of the double-emitting layer blue organic electroluminescent device. While retaining the voltage reduction advantage of SOP, the compounds effectively suppress the accumulation of interface charge and exciton quenching, so that the blue OLED device has both low driving voltage and high efficiency.

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A benzanthracene-based organic electroluminescent compound, characterized in that, Its general structural formula is shown in Formula I. I In formula I, Ar1 is selected from or Ring A represents a benzene ring or a naphthalene ring; Ar2 is selected from substituted or unsubstituted non-fused aryl groups with 6 to 20 carbon atoms, and substituted or unsubstituted fused aryl groups with 10 to 30 carbon atoms; In Formula I, any hydrogen atom can be independently replaced by deuterium.

2. The benzene-anthracene organic electroluminescent compound as described in claim 1, characterized in that, Ar1 is selected from the following structures, whether deuterated or non-deuterated: , , , or ; The non-fused aryl group is selected from phenyl or biphenyl, and the fused aryl group is selected from naphthyl, phenanthryl or pyrene.

3. The benzanthracene-based organic electroluminescent compound as described in claim 1, characterized in that, Ar2 is selected from substituted or unsubstituted phenyl, biphenyl, naphthyl, phenanthryl or pyrene; when Ar2 has a substituent, the substituent is deuterium or phenyl.

4. The benzanthracene-based organic electroluminescent compound as described in claim 3, characterized in that, Ar2 is selected from phenyl, biphenyl, naphthyl, phenyl-substituted naphthyl, phenanthryl or pyrene, and any one of the hydrogen atoms in Ar2 can be independently substituted with deuterium.

5. The benzene-anthracene organic electroluminescent compound as described in claim 1, characterized in that, Ar1 is selected from the following structures, whether deuterated or non-deuterated: ； Ar2 is selected from the following structures, whether deuterated or non-deuterated: 。 6. The benzene-anthracene organic electroluminescent compound as described in claim 1, characterized in that, The structure of the benzanthracene-based organic electroluminescent compound is selected from any one of the following structural formulas: In the above structural formula of the benzanthracene-type organic electroluminescent compound, any hydrogen atom can be independently replaced by deuterium; Dn represents the substitution of n hydrogen atoms by deuterium in the structural formula, where n is a positive integer and takes values ​​from 1 to the maximum deuterium algebra.

7. A dual-emitting-layer organic electroluminescent device, characterized in that, It includes a first light-emitting layer and a second light-emitting layer stacked adjacent to each other; the first light-emitting layer is closer to the hole transport side, and the second light-emitting layer is closer to the electron transport side; the raw material of the first light-emitting layer includes the benzene-anthracene organic electroluminescent compound as described in any one of claims 1 to 6.

8. The dual-emitting-layer organic electroluminescent device as described in claim 7, characterized in that, The dual-emitting-layer organic electroluminescent device comprises, from bottom to top, an anode, a hole transport region, an electron blocking layer, a first emitting layer, a second emitting layer, a hole blocking layer, an electron transport region, and a cathode, which are sequentially disposed on a substrate. The raw materials of the first emitting layer include a first host material and a first guest material, wherein the first host material includes one or more of the benzene-anthracene-based organic electroluminescent compounds.

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