A boron-containing polycyclic compound for organic light-emitting materials

Abstract

The present invention belongs to the technical field of organic light-emitting materials, and relates to a boron-containing polycyclic compound for organic light-emitting materials. The present invention takes an aryl or heteroaryl as the center, introduces 2 to 3 boron atoms, and forms covalent bonds with atoms such as N, O, S, and Se to construct a rigid polycyclic compound. The compound of the present invention is a boron-containing polycyclic compound with multiple resonance effects, which can not only achieve narrow-spectrum and high-color-purity luminescence, but also has efficient TADF characteristics, significantly improving the performance of OLED devices. Compared with the prior art, the present invention has significant advantages in terms of molecular structure design, optoelectronic property regulation, and application scope, providing important technical support for the development of a new generation of high-performance OLED materials, and having broad market prospects and application potential.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic light-emitting materials, and relates to a boron-containing polycyclic compound for organic light-emitting materials. Background Art

[0002] Organic electroluminescent devices (OLEDs) have developed rapidly as a new type of solid-state lighting technology and have gradually become the mainstream display technology. Organic electroluminescent devices generally have a structure including an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode. In the above device structure, when an external electric field is applied, holes are injected into the organic layer from the anode, and electrons are injected into the organic layer from the cathode. When the injected holes and electrons meet in the light-emitting layer, excitons are formed. When the excitons transition back to the ground state, energy is released, thereby emitting light.

[0003] With the rapid iterative development of new display technologies, the market's demand for high-quality display effects is increasing day by day. To meet this demand, display standards (such as BT.2020) have set unprecedentedly high requirements for the color purity of devices. Taking blue light as an example, its color coordinates are required to reach CIEy = 0.046, which poses extremely stringent requirements for the full width at half maximum of the emission spectrum of the light-emitting material. Traditional fluorescent materials are difficult to meet this index due to their relatively wide spectra. Therefore, the development of new light-emitting materials with narrow spectra and high color purity has become an important research direction in the display technology field.

[0004] In this context, a new generation of thermally activated delayed fluorescence materials (MR-TADF) with multiple resonance effects has attracted extensive attention in the academic and industrial circles due to their unique molecular configurations and excellent optoelectronic properties. MR-TADF materials achieve multiple resonance effects through the interaction of holes and electrons within the molecule, which can significantly reduce the Stokes shift and narrow the emission spectrum, thereby achieving high-color-purity luminescence. At the same time, these materials also possess thermally activated delayed fluorescence (TADF) characteristics, which can utilize the energy of both singlet (S1) and triplet (T1) states and convert triplet excitons into singlet excitons through the reverse intersystem crossing (RISC) process. In theory, an internal quantum efficiency of 100% can be achieved, greatly improving the luminescence efficiency of the device.

[0005] However, the development of high-performance MR-TADF materials, especially blue-light materials, faces many challenges. First, blue-light materials need to have a large bandgap, which poses high requirements for molecular design; second, in order to achieve efficient TADF characteristics, the energy level difference (ΔE) between the singlet and triplet states stIt is usually less than 0.1 eV, which poses extremely high requirements for the fine regulation of molecular structures. Finally, the realization of the multiple resonance effect requires the molecule to have a specific rigid polycyclic configuration and electron distribution, which poses a huge challenge to synthetic chemistry and molecular engineering. Therefore, how to design and synthesize new MR-TADF materials that simultaneously meet the requirements of wide bandgap and multiple resonance effects has become a research hotspot and difficulty in the current field of display materials.

[0006] To solve these problems, researchers are exploring new molecular structures and synthetic strategies through a combination of theoretical calculations and experiments. For example, introducing atoms such as boron and nitrogen to form a rigid polycyclic structure, or regulating the electron distribution through substituents to achieve the synergistic optimization of the multiple resonance effect and TADF characteristics. In addition, device engineering optimization (such as multi-layer interface regulation, carrier balance, etc.) is also widely used to further improve the performance of MR-TADF materials.

[0007] In summary, as a new generation of luminescent materials, MR-TADF materials exhibit great application potential in the field of high-quality displays due to their narrow spectra, high color purity, and high efficiency. The boron-containing polycyclic compound of the present invention, as a potential MR-TADF material, not only realizes narrow-spectrum emission but also provides new ideas and solutions for solving the key problems in the development of current MR-TADF materials, and has important scientific significance and industrial value. Summary of the Invention

[0008] In view of this, the purpose of the present invention is to provide a boron-containing polycyclic compound for organic luminescent materials, which takes an aryl or heteroaryl as the center, introduces 2 to 3 boron atoms, and forms covalent bonds with atoms such as N, O, S, and Se to construct a rigid polycyclic compound, which can be used as an MR-TADF material in organic electroluminescent devices.

[0009] In the first aspect, the present invention provides a compound having a structure represented by Formula I or Formula II,

[0010] , ;

[0011] wherein, X1 and X2 in Formula I or Formula II are each independently selected from any one of CR1 and N;

[0012] Y1 and Y2 in Formula I or Formula II are each independently selected from any one of NR2, O, S, and Se;

[0013] Ar1, Ar2, Ar3, and Ar4 in Formula I or Formula II are each independently selected from any one of H, D, C1-C5 alkyl, substituted or unsubstituted amino groups, and substituted or unsubstituted C6-C30 aryl heteroaryls.

[0014] Further, in the compound provided by the present invention, R1 in CR1 is selected from any one of H, D, B, cyano, substituted or unsubstituted amino group, substituted or unsubstituted aryl heteroaryl, or is linked to the adjacent benzene ring.

[0015] Further, in the compound provided by the present invention, R2 in NR2 is a substituted or unsubstituted aryl heteroaryl, or is covalently linked to the adjacent B.

[0016] Further, in the compound provided by the present invention, when Y1 and Y2 are N atoms, it has the structures shown in Formula III or Formula IV.

[0017] 。

[0018] Further, in the compound provided by the present invention, when X1 and X2 are CR1 or N, it has the structures shown in Formula A1 - A4 or Formula B1 - B2.

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[0020] 。

[0021] Further, in the compound provided by the present invention, it has the following structure.

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[0070] ;

[0071] Among them, D represents that the hydrogen atom is deuterated.

[0072] In a second aspect, the present invention provides the use of the above compound in an organic electroluminescent device.

[0073] In a third aspect, the present invention provides the use of the above compound in an organic electroluminescent device.

[0074] In a fourth aspect, the present invention provides an organic electroluminescent device, including an anode layer, a cathode layer, and an organic thin film layer located between the anode layer and the cathode layer. The organic thin film layer includes a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer, and the light emitting layer contains the above compound.

[0075] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages:

[0076] (1) By introducing two or three boron atoms into aryl and heteroaryl molecules and forming covalent bonds with atoms such as N, O, S, and Se, the present invention constructs a rigid polycyclic compound. This structure not only gives the molecule a large degree of twist but also effectively regulates the energies of the singlet state (S1) and the triplet state (T1), achieving a small energy difference between the singlet state and the triplet state (ΔE st), thus enhancing the multiple resonance effect and thermally activated delayed fluorescence (TADF) characteristics. The central aryl or heteroaryl group participates in conjugation, further improving the intramolecular charge distribution and enhancing the MR-TADF effect, enabling the material to utilize both singlet and triplet excitons and theoretically achieving 100% internal quantum efficiency.

[0077] (2) Due to the introduction of the multiple resonance effect, the compounds provided by the present invention can significantly reduce the Stokes shift and narrow the full width at half maximum of the emission spectrum, thereby achieving high color purity luminescence.

[0078] (3) The compounds provided by the present invention have appropriate HOMO and LUMO energy levels, can effectively balance the injection and transport of holes and electrons, and improve the recombination efficiency of excitons in the light-emitting layer. Combining with the MR-TADF effect, when the material is used as the light-emitting layer in an organic light-emitting device (OLED), it can significantly improve the luminescence efficiency and external quantum efficiency of the device.

[0079] (4) The compounds provided by the present invention are not only applicable to OLED light-emitting devices, but also can be widely used in various display devices, such as smart phones, televisions, tablet computers, wearable devices, etc. Their characteristics of high efficiency, narrow spectrum and high color purity make them have important industrialization value in the fields of high-quality display and lighting. Description of the Drawings

[0080] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0081] Figure 1 It is a schematic structural diagram of an organic light-emitting element. Among them, 1 is a substrate, 2 is an anode layer, 3 is a hole injection layer, 4 is a hole transport layer, 5 is an electron blocking layer, 6 is a light-emitting layer, 7 is a hole blocking layer, 8 is an electron transport layer, 9 is an electron injection layer, and 10 is a cathode layer. Detailed Embodiments

[0082] Next, the technical solutions of the present invention will be described in conjunction with the embodiments. However, the present invention is not limited to the following embodiments. The experimental methods and detection methods described in each embodiment are all conventional methods unless otherwise specified; the reagents and materials described are all commercially available unless otherwise specified. The percentages in the following embodiments are all mass percentages unless otherwise specified.

[0083] Preparation Examples

[0084] This preparation example provides the synthesis methods of some intermediates and compounds. The synthesis methods of the remaining intermediates and compounds are all similar methods and can be easily synthesized. The specific synthesis routes are shown as follows.

[0085] Synthesis of Intermediate 2:

[0086]

[0087] Synthesis of Intermediate 2: Under nitrogen protection, add raw material 1 (30.00 g, 96.7 mmol), raw material 2 (14.47 g, 44.0 mmol), potassium carbonate (18.21 g, 132.0 mmol) and DMF (300 mL) to the reaction flask, then add Pd2(dba)3 (tris(dibenzylideneacetone)dipalladium, 1.61 g, 1.76 mmol) and X-Phos (2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl, 1.67 g, 3.52 mmol), and heat to 120 °C for reaction for 4 h. After the reaction is completed, cool to room temperature, pour into water, and white precipitate is formed, then filter. Wash the precipitate with water and ethanol in sequence. Finally, obtain Intermediate 2 (17.35 g, yield 50%) through silica gel column and recrystallization.

[0088] Synthesis of Compound 1: Under nitrogen protection, add Intermediate 2 (15.30 g, 19.4 mmol) and o-dichlorobenzene (50 mL) to the three-necked flask equipped with a condenser in sequence, then slowly dropwise add boron tribromide (29.10 g, 116.4 mmol), and heat to 150 °C - 160 °C for reaction for 8 h. After the reaction is completed, cool the system to room temperature. Add a large amount of water, and white precipitate is formed, then filter. Wash the filter cake with water and ethanol in sequence for the filter solid, and finally obtain Compound 2 (7.02 g, yield 45%) through silica gel column and recrystallization.

[0089] The characterization results of the obtained sample are as follows: HRMS: Measured value: 805.4846 [M+H] + ; Exact mass: 805.4859. C 58 H 58 Calculated values for C21H22B2N2 (%): C, 86.56%; H, 7.27%; N, 3.48%; Measured values: C, 86.49%; H, 7.20%; N, 3.38%.

[0090] Synthesis of Compound 13:

[0091]

[0092] For the synthesis of Intermediate 13-1, refer to the synthesis of Intermediate 2 and replace raw material 2 with raw material 3.

[0093] Synthesis of Intermediate 13-2: Under nitrogen protection, into a three-necked flask equipped with a condenser, add Intermediate 13-1 (21.00 g, 26.5 mmol), dichloromethane (200 mL) in sequence, cool down to 0 °C - 5 °C, and then slowly dropwise add boron tribromide (7.28 g, 29.2 mmol). After the reaction is completed, pour the system into a large amount of ice water and filter. Wash the filter cake with water and ethanol successively, and finally obtain Intermediate 13-2 (18.23 g, yield 90%) through silica gel column and recrystallization.

[0094] The synthesis of Compound 13 refers to the synthesis of Compound 2, replacing Intermediate 2 with Intermediate 13-1.

[0095] The characterization results of the obtained sample are as follows: LC-MS: Measured value: 781.4376 [M+H] + ; Exact mass: 781.4383. C 56 H 54 Calculated values for C, H, O2B2 (%): C, 86.16%; H, 6.97%; Measured values: C, 86.07%; H, 6.90%.

[0096] Synthesis of Compound 26:

[0097]

[0098] The synthesis of Compound 26 refers to the synthesis of Compound 2, replacing Raw Material 2 with Raw Material 4.

[0099] Synthesis of Compound 33:

[0100]

[0101] The synthesis of Compound 33 refers to the synthesis of Compound 13, replacing Raw Material 3 with Raw Material 5.

[0102] The characterization results of the obtained sample are as follows: HRMS: Measured value: 821.4326 [M+H] + ; Exact mass: 821.4332. C 58 H 54 Calculated values for C, H, O3B2 (%): C, 84.88%; H, 6.63%; Measured values: C, 84.80%; H, 6.54%.

[0103] Synthesis of Compound 34:

[0104]

[0105] The synthesis of Compound 34 refers to the synthesis of Compound 2, replacing Raw Material 2 with Raw Material 6.

[0106] The characterization results of the obtained sample are as follows: HRMS: measured value: 807.4756 [M+H] + ; exact mass: 807.4764. C 56 H 56 Calculated values for C 56 H 56 B2N4 (%): C, 83.38%; H, 7.00%; N, 6.95%; found: C, 83.30%; H, 6.91%; N, 6.88%.

[0107] Synthesis of Compound 105:

[0108]

[0109] The synthesis method of Intermediate 105 refers to the synthesis of Intermediate 2, with Raw Material 2 replaced by Raw Material 7.

[0110] Synthesis of Compound 105: Under nitrogen protection, Intermediate 105 (15.30 g, 19.4 mmol), o-dichlorobenzene (50 mL) were successively added to a three-necked flask equipped with a condenser, and then boron tribromide (48.4 g, 193.6 mmol) was slowly added dropwise. The mixture was heated to 170 °C - 180 °C and reacted for 8 h. After the reaction was completed, the system was cooled to room temperature. A large amount of water was added, and a white precipitate was formed. The precipitate was filtered. The filter cake was washed successively with water and ethanol, and finally Compound 105 (10.23 g, yield 65%) was obtained by silica gel column chromatography and recrystallization.

[0111] The characterization results of the obtained sample are as follows: HRMS: measured value: 814.4752 [M+H] + ; exact mass: 814.4760. C 57 H 54 Calculated values for C + H 57 B3N3 (%): C, 84.16%; H, 6.69%; N, 5.17%; found: C, 84.10%; H, 6.57%; N, 5.06%.

[0112] Synthesis of Compound 123:

[0113]

[0114] The synthesis of Intermediate 123-2 refers to the synthesis of Compound 105, with Raw Material 7 replaced by Raw Material 9 (9.80 g, yield 58%).

[0115] Synthesis of Intermediate 123-3: Under nitrogen protection, add Intermediate 123-2 (9.5 g, 15.4 mmol), bis(pinacolato)diboron (4.70 g, 18.5 mmol) and decalin (100 mL) to a reaction flask, then add methoxy(cyclooctadiene)iridium dimer (0.21 g, 0.31 mmol) and 4,4′-di-tert-butyl-2,2′-bipyridine (dtbpy, 0.16 g, 0.62 mmol), and heat to 100 °C for reaction for 16 h. After the reaction is completed, wash with water successively, pass through a silica gel column and recrystallize to obtain Intermediate 123-3 (6.85 g, yield 60%).

[0116] Synthesis of Compound 123: Under nitrogen protection, add Intermediate 123-3 (6.00 g, 8.1 mmol), Raw Material 10 (2.15 g, 8.0 mmol), potassium carbonate (1.66 g, 12.0 mmol), dioxane (60 mL) and water (8 mL) to a reaction flask, then add Pd(dppf)Cl2 (1,1'-bis(diphenylphosphino)ferrocene dichloropalladium, 0.041 g, 0.06 mmol), and heat to 90 °C for reaction for 6 h. After the reaction is completed, cool to room temperature, pour into water to form a white precipitate, and filter. Wash the precipitate with water and ethanol successively. Finally, pass through a silica gel column and recrystallize to obtain Compound 123 (5.10 g, yield 75%).

[0117] The characterization results of the obtained sample are as follows: HRMS: Measured value: 848.3315 [M+H] + ; Exact mass: 848.3323. C 59 H 36 Calculated values for C, H, B3N5 (%): C, 83.63%; H, 4.28%; N, 8.26%; Measured values: C, 86.50%; H, 7.18%; N, 3.40%.

[0118] Synthesis of Compound 189:

[0119]

[0120] The synthesis of Compound 189 refers to the synthesis of Compound 2, and replace Raw Material 2 with Raw Material 12 (8.50 g, yield 54%).

[0121] The characterization results of the obtained sample are as follows: HRMS: Measured value: 806.4806 [M+H] + ; Exact mass: 806.4811. C 57 H 57 Calculated values for C, H, B2N3 (%): C, 84.97%; H, 7.13%; N, 5.22%; Measured values: C, 84.90%; H, 7.05%; N, 5.18%.

[0122] Synthesis of Compound 190:

[0123]

[0124] The synthesis of Compound 190 refers to the synthesis of Compound 2, replacing raw material 2 with raw material 13 (10.50 g, yield 60%).

[0125] The characterization results of the obtained sample are as follows: HRMS: Measured value: 957.5479 [M+H] + ; Exact mass: 957.5485. C 70 H 66 Calculated values for C, H, B2N2 (%) are: C, 87.86%; H, 6.95%; N, 2.93%; Measured values are: C, 87.79%; H, 6.86%; N, 2.84%.

[0126] The present invention demonstrates the performance parameters of the synthesized Compounds 2, 10, 13, 26, 33, 34, 47, 52, 58, 61, 68, 72, 89, 93, 105, 123, 134, 138, 145, 152, 159, 166, 176, 185, 186, 189, 190 and the existing luminescent material BD01, including T1 energy level, S1, HOMO (highest occupied molecular orbital), and LUMO (lowest unoccupied molecular orbital), etc. HOMO, LUMO, S1, and T1 are data obtained from simulation calculations. The calculation method uses the B3LYP hybrid functional and the basis set 6-31g(d,p). The calculation results are shown in Table 1.

[0127] Table 1 Simulation calculation results of HOMO, LUMO, S1, and T1

[0128]

[0129] As can be seen from Table 1, the compounds of the present invention have appropriate HOMO energy levels and LUMO energy levels, and the singlet-triplet energy difference (ΔEst) is smaller, making it easier for intersystem crossing inversion from triplet state to singlet state to occur.

[0130] Taking some of the compounds provided by the present invention as examples below, they are applied as luminescent host materials in organic electroluminescent devices to verify the excellent effects achieved.

[0131] The excellent effects of the OLED materials of the present invention applied in devices are specifically illustrated by the device performances of Examples 1 to 27 and Comparative Example 1. The fabrication processes of the structures of Examples 1 to 27 and Comparative Example 1 of the present invention are exactly the same, and the same glass substrate and electrode materials are used, and the film thicknesses of the electrode materials are also kept consistent. The difference is that the host materials of the light-emitting layer are adjusted as follows.

[0132] Comparative Example 1

[0133] This comparative example provides an organic electroluminescent device, and its structure is specifically as Figure 1 shown, including a substrate 1, an anode layer 2, a hole injection layer 3, a hole transport layer 4, an electron blocking layer 5, a light-emitting layer 6, a hole blocking layer 7, an electron transport layer 8, an electron injection layer 9, and a cathode layer 10 which are sequentially stacked.

[0134] Among them, the substrate 1 is a glass substrate with a thickness of 0.7 mm; the material of the anode layer 2 is indium tin oxide (ITO) with a high work function; the material of the hole injection layer 3 is HT1 doped with HI-1, with a mass ratio of 95:5 and a thickness of 10 nm; the material of the hole transport layer 4 is HT1, with a thickness of 60 nm; the material of the electron blocking layer 5 is EB1, with a thickness of 15 nm; the light-emitting layer 6 uses BH1 as the host material and BD01 as the light-emitting material, with a doping mass ratio of 5% and a thickness of 30 nm; the material of the hole blocking layer 7 is HB, with a thickness of 10 nm; the material of the electron transport layer 8 is composed of ET-1 doped with Liq, with a doping concentration of w50% and a thickness of 30 nm; the material of the electron injection layer 9 is Liq, with a thickness of 2 nm; the material of the cathode layer 10 is Al, with a thickness of 100 nm.

[0135] The basic material structural formulas used in each functional layer of the device are as follows:

[0136]

[0137]

[0138] The specific preparation steps of the above organic electroluminescent device are as follows:

[0139] (1) Clean the ITO anode layer on the transparent glass or plastic substrate, ultrasonically clean it with deionized water, acetone, and ethanol for 20 min each, and then perform plasma treatment in an oxygen atmosphere for 5 min;

[0140] (2) On the ITO anode layer, deposit the hole injection layer material HT1:HI-1 with a mass ratio of 97:3 and a thickness of 10 nm by vacuum evaporation, and this layer serves as the hole injection layer;

[0141] (3) A hole transport material HT1 is deposited on the hole injection layer by vacuum evaporation, with a thickness of 60 nm, and this layer serves as the hole transport layer;

[0142] (4) An electron blocking layer material EB1 is deposited on the hole transport layer HT1 by vacuum evaporation, with a thickness of 15 nm, and this layer serves as the electron blocking layer;

[0143] (5) On the electron blocking layer, a light-emitting layer is deposited by vacuum evaporation or co-evaporation. BH1 is used as the host material and RD01 is used as the light-emitting material, with a doping mass ratio of 5% and a thickness of 30 nm;

[0144] (6) A hole blocking material HB is deposited on the light-emitting layer by vacuum evaporation, with a thickness of 10 nm, and this layer serves as the hole blocking layer;

[0145] (7) An electron transport material ET-1:Liq with a mass ratio of 1:1 is deposited on the hole blocking layer by vacuum evaporation, with a thickness of 30 nm, and this layer serves as the electron transport layer;

[0146] (8) An electron injection material Liq is deposited on the electron transport layer by vacuum evaporation, with a thickness of 2 nm, and this layer serves as the electron injection layer;

[0147] (9) A cathode Al is deposited on the electron injection layer by vacuum evaporation, with a thickness of 100 nm. This layer is used as the cathode conductive electrode, and this layer is the cathode layer.

[0148] Examples 1 to 27

[0149] The implementation processes of Examples 1 to 27 are the same as those of Comparative Example 1, except that the light-emitting materials of the light-emitting layer in Comparative Example 1 are replaced with the compounds 2, 10, 13, 26, 33, 34, 47, 52, 58, 61, 68, 72, 89, 93, 105, 123, 134, 138, 145, 152, 159, 166, 179, 185, 186, 189 and 190 provided by the present invention as the light-emitting materials of the light-emitting layer.

[0150] The cathode and anode of each organic electroluminescent device are connected by a well-known drive circuit, and the voltage-efficiency-current density relationship of the OLED device is tested by using a Keithley 2400 power supply combined with a PR670 photometer by a standard method. The test results are shown in Table 2.

[0151] Table 2 Comparison Table of Device Emission Layer Compositions and Device Performance of Each Example

[0152]

[0153] As can be seen from the data in Table 2, the compounds provided by the present invention, when used as luminescent materials in OLED devices, exhibit excellent performance. Compared with the BD01 material described in Comparative Example 1, the compounds of the present invention have significant advantages in the following aspects: (1) Improved luminous efficiency: When the compounds of the present invention are used as luminescent materials, the luminous efficiency of the OLED devices is significantly improved. This is due to the small singlet-triplet energy level difference (ΔE st ), which enables excitons to efficiently achieve radiative recombination through the thermally activated delayed fluorescence (TADF) mechanism; (2) Narrower full width at half maximum: Due to the multiple resonance thermally activated delayed fluorescence (MR-TADF) effect of the compounds of the present invention, the full width at half maximum of their emission spectra is significantly narrowed; (3) Molecular structure advantages: The diboron polycyclic compounds provided by the present invention have a highly twisted molecular structure. This structure not only ensures the rigidity of the compounds but also enhances the multiple resonance effect, further optimizing the optoelectronic properties of the materials. The compounds have appropriate HOMO and LUMO energy levels, which can effectively balance the injection and transport of holes and electrons, improving the overall performance of the devices.

[0154] Through innovative molecular design, the present invention has successfully developed a class of diboron polycyclic compounds with multiple resonance effects. When these compounds are used as luminescent materials in OLED devices, they exhibit significant advantages of high efficiency, narrow spectrum, and high color purity, and have important scientific significance and industrialization value.

[0155] As described above, the basic principles, main features, and advantages of the present invention are preferably described. The above embodiments and the description are only for describing the preferred embodiments of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, various changes and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the present invention.

Claims

1. A compound, characterized in that, Having a structure represented by Formula I or Formula II, ， ； wherein X1 and X2 in Formula I or Formula II are each independently selected from CR1 and N; Y1 and Y2 in Formula I or Formula II are each independently selected from NR2, O, S, and Se; Ar1, Ar2, Ar3, and Ar4 in Formula I or Formula II are each independently selected from H and C4 alkyl; R1 in CR1 is selected from H, D, B, cyano, amino, aryl heteroaryl; R2 in NR2 is aryl heteroaryl; when Y1 and Y2 are NR2, it has a structure represented by Formula III or Formula IV; ； when X1 and X2 are CR1 or N, it has a structure represented by Formula A1 - A4 or Formula B1 - B2; 。 2. The compound according to claim 1, characterized in that, having the following structure, ； wherein D represents that the hydrogen atom is deuterated.

3. Use of the compound according to any one of claims 1 - 2 in an organic electroluminescent device.

4. Use of the compound according to any one of claims 1 - 2 in an organic electroluminescent device.

5. An organic electroluminescent device, comprising an anode layer, a cathode layer, and an organic thin film layer located between the anode layer and the cathode layer, wherein the organic thin film layer includes a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer, characterized in that, The light - emitting layer contains the compound according to any one of claims 1 - 2.

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