A boron-nitrogen compound based on a double-heteroanthracene fused ring aromatic hydrocarbon and an electroluminescent device thereof

Abstract

The present application relates to the technical field of organic electroluminescence, and discloses a boron-nitrogen compound based on a double-heteroanthracene fused ring arene and an electroluminescent device thereof.The compound has a structure represented by HU, wherein H has a structure of formula 1-1, and U is selected from a structure of formula 2, wherein any two adjacent single bonds in the structure formula U are connected with the '' in the structure formula H, X and Y are the same or different at each occurrence and are selected from a single bond, O, S, Se, NR', CR''R''' or SiR''R'''', and combinations thereof.The OLED device prepared by using the compound has a low starting voltage, high luminous efficiency and a more optimal service life.

Description

Technical Field

[0001] This invention relates to the field of organic compound technology, and more specifically to a boron nitrogen compound based on dianthracene polycyclic aromatic hydrocarbons and electroluminescent devices, compositions and display components containing the same. Background Technology

[0002] Organic light-emitting diodes (OLEDs), as the core of next-generation display technology, have been successfully applied to mainstream consumer electronics products such as smartphones, tablets, smart TVs, and wearable devices due to their outstanding advantages, including self-emission, high contrast, wide color gamut, fast response, thinness and flexibility, and low power consumption. They also demonstrate enormous application potential in emerging fields such as automotive displays, transparent displays, and Micro / Mini OLEDs, becoming a key direction for the transformation and upgrading of the global display industry. From a technological development perspective, the research and iteration of OLED materials is the core driving force behind breakthroughs in device performance, evolving from traditional fluorescent materials and phosphorescent materials to thermally activated delayed fluorescence (TADF) materials and multiple resonance thermally activated delayed fluorescence (MR-TADF) materials. Early fluorescent materials were limited by a singlet exciton utilization rate of 25%, resulting in low luminescence efficiency. While phosphorescent materials achieved 100% exciton utilization through spin-orbit coupling of heavy metal atoms, significantly improving efficiency, the introduction of noble metals (such as Ir and Pt) led to high material costs and problems such as a wide full width at half maximum (FWHM) and insufficient color purity. TADF materials, through the construction of narrow singlet-triple band gaps (… ΔE ST The reverse gap crossing of excitons has been achieved, breaking the dependence on noble metals, but its carrier transport balance and device stability still need to be optimized; MR-TADF materials have achieved intrinsic narrow-band emission with their unique molecular orbital distribution, making them an ideal material choice for ultra-high-definition displays, but their synthesis process control and device compatibility still face challenges.

[0003] Currently, research in the field of OLED materials focuses on developing systems that combine high luminous efficiency, long lifespan, low driving voltage, and narrow-band emission characteristics to meet market demands for ultra-high definition, high refresh rates, and long battery life. Among these, boron-nitrogen (BN)-doped aromatic compounds have attracted significant attention due to their unique electronic structure tuning advantages: the empty p orbitals of the B atom and the lone pair electrons of the N atom can form effective conjugation, constructing frontier molecular orbitals with non-bonding characteristics, significantly suppressing intramolecular vibrational coupling, thereby achieving intrinsic narrow-band absorption and emission, providing a new solution to overcome the color purity bottleneck of traditional materials. Furthermore, polycyclic aromatic hydrocarbons (PAHs) have always been an important research branch of OLED materials due to their excellent carrier transport capabilities and good thermal stability resulting from their large π-conjugated systems. While dianthracene PAHs, as one type, possess a certain degree of electronic structure tunability, related research is still in its early stages.

[0004] Although OLED technology has been industrialized, device performance and industrial applications still face several core bottlenecks: First, the performance shortcomings of blue luminescent materials in full-color displays are particularly prominent. Existing blue fluorescent materials have low efficiency, while blue phosphorescent and TADF materials suffer from short lifespan, high driving voltage, and insufficient color purity, severely restricting the overall lifespan and display quality of full-color devices. Second, the energy level matching and carrier transport efficiency of materials are difficult to balance, resulting in low exciton recombination efficiency within the device. Although some high-performance materials can achieve efficient light emission, they suffer from carrier transport imbalance and are prone to aggregation and quenching, affecting device stability. Third, the synthesis processes of some high-performance materials (such as noble metal phosphorescent materials and complex structure MR materials) are complex and cumbersome, resulting in high material costs and hindering their large-scale industrial application. Fourth, flexible OLED devices place higher demands on the mechanical and thermal stability of materials, and the film formation quality and long-term stability of existing materials on flexible substrates still need to be improved.

[0005] Therefore, addressing the technical challenges of existing OLED materials, rationally designing molecular structures, fully utilizing novel modulation strategies such as boron and nitrogen doping, and combining the excellent carrier transport characteristics of polycyclic aromatic hydrocarbons, to develop novel organic electroluminescent materials with high luminous efficiency, long lifetime, low driving voltage, and narrow-band emission, and to realize their effective application in high-performance OLED devices, has become a core technical problem that urgently needs to be solved in this field. This is of great significance for promoting the development of OLED technology towards ultra-high definition, flexibility, and low cost. Summary of the Invention

[0006] The purpose of this invention is to provide a boron-nitrogen compound based on dianthracene polycyclic aromatic hydrocarbons and electroluminescent devices, compositions, and display components containing the same to address the aforementioned problems. The compound can be used as a luminescent material in electroluminescent devices, effectively improving device efficiency, exhibiting better color purity, and providing better device stability. OLED devices prepared using the compounds of this invention exhibit low start-up voltage, high luminous efficiency, and superior lifespan.

[0007] In a first aspect, the present invention provides a boron-nitrogen compound based on dianthracene polycyclic aromatic hydrocarbons. The technical solution adopted is as follows: A boron-nitrogen compound based on dianthracene polycyclic aromatic hydrocarbons, having the structure represented by HU, Wherein, H has the structure of Equation 1-1, which is expressed as:

[0008] The U is selected from a structure having Equation 2, which is expressed as:

[0009] “ "Indicates the location where H and U are connected; " on ring 4 "Indicates adjacent substitution; in, X and Y are selected from single bonds, O, S, Se, NR', CR''R''' or SiR''R''', and combinations thereof, each time they appear, either identically or differently. R 1 To R 6 R', R'', and R''' are selected, in the same or different manner, from the group consisting of: hydrogen, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, and substituted or unsubstituted aryloxy groups having 6-30 carbon atoms. Substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted alkynyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms. R 1 To R 6 Each occurrence indicates either single or multiple substitution; Adjacent substituent R 1 To R 6 R', R'', and R''' can be optionally connected to form a ring.

[0010] A boron-nitrogen compound based on dianthracene polycyclic aromatic hydrocarbons, having a structure represented by H(U)2, Wherein, H has the structure of Equation 1-2 (Equation 1-2 is included in Equation 1-1), and Equation 1-2 is expressed as:

[0011] The U is selected from a structure having Equation 2, which is expressed as:

[0012] “ "Indicates the location where H and U are connected; " on ring 4 "Indicates adjacent substitution; in, X and Y are selected from single bonds, O, S, Se, NR', CR''R''' or SiR''R''', and combinations thereof, each time they appear, either identically or differently. Among them, R 1 R 2 R 4 R 5 R 6 R', R'', and R''' are selected, in the same or different manner, from the group consisting of: hydrogen, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, and substituted or unsubstituted aryloxy groups having 6-30 carbon atoms. Substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted alkynyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms. R 1 To R 6 Each occurrence indicates either single or multiple substitution; Adjacent substituent R 1 To R 6 R', R'', and R''' can be optionally connected to form a ring.

[0013] Ring 1, ring 2, ring 3, ring 4, ring 5 and ring 6 are selected from five-membered unsaturated carbon rings, aromatic rings with 6-30 carbon atoms, or heteroaromatic rings with 3-30 carbon atoms each time they appear; Preferably, the rings 1, 2, 3, 4, 5 and 6 are selected from five-membered unsaturated carbon rings, aromatic rings having 6-18 carbon atoms, or heteroaromatic rings having 3-18 carbon atoms each time they appear. More preferably, the rings 1, 2, 3, 4, 5, and 6 are selected from 5-membered unsaturated carbon rings, benzene rings, 5-membered heteroaromatic rings, or 6-membered heteroaromatic rings each time they appear.

[0014] In one embodiment of the present invention, the compound according to any one of the following formulas is selected from the structures represented by formulas I to V: , , , ,

[0015] in, X and Y are selected, in the same or different manner, from single bonds, O, S, Se, NR', CR''R''' or SiR''R''', and combinations thereof; more preferably, X and Y are selected, in the same or different manner, from the group consisting of single bonds, O, S, Se, NR'.

[0016] R 1 To R 6 R', R'', and R''' are selected, in the same or different manner, from the group consisting of: hydrogen, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, and substituted or unsubstituted aryloxy groups having 6-30 carbon atoms. Substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted alkynyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms. R 1 To R 6 Each occurrence indicates either single or multiple substitution; Adjacent substituent R 1 To R 6 R', R'', and R''' can be optionally connected to form a ring.

[0017] In one embodiment of the present invention, any of the compounds described herein is selected from the group consisting of: structures corresponding to compounds 1 to 190, structures obtained by partially or completely replacing hydrogen in any of the structures corresponding to compounds 1 to 190 with deuterium, and combinations thereof; the structures represented by compounds 1 to 190 respectively correspond to structures selected from the group consisting of:

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026] In a second aspect, the present invention provides the application of the boron nitrogen compound based on dianthracene polycyclic aromatic hydrocarbons described in the first aspect in electroluminescent devices.

[0027] Preferably, the boron-nitrogen compound based on dianthracene polycyclic aromatic hydrocarbons is used in the organic layer of the organic electroluminescent device; more preferably, the boron-nitrogen compound based on dianthracene polycyclic aromatic hydrocarbons is used in the hole injection layer of the organic electroluminescent device; even more preferably, the amount of the boron-nitrogen compound based on dianthracene polycyclic aromatic hydrocarbons in the hole injection layer is 0.1~30% of the total weight of the hole injection layer.

[0028] Thirdly, the present invention provides an organic electroluminescent device comprising the boron nitrogen compound based on dianthracene polycyclic aromatic hydrocarbons as described in the first aspect.

[0029] Preferably, the organic electroluminescent device includes an anode, a cathode, and an organic layer disposed between the anode and the cathode, the organic layer comprising the organic electroluminescent device based on a boron nitrogen compound of a dianthracene polycyclic aromatic hydrocarbon as described in the first aspect.

[0030] Preferably, the organic layer is a hole injection layer, which comprises the boron-nitrogen compound based on dianthracene polycyclic aromatic hydrocarbons as described in the first aspect; and the compound serves as a luminescent material. The hole injection layer further comprises at least one hole transport material, which includes compounds having triarylamine units, spirodifluorene compounds, pentanebenzene compounds, oligothiophene compounds, oligophenyl compounds, oligophenylenevinylene compounds, oligofluorene compounds, porphyrin complexes, or metal phthalocyanine complexes.

[0031] Preferably, one or more of the organic layers in the organic electroluminescent device are formed by deposition or solution method.

[0032] Fourthly, the present invention also provides a display component comprising the electroluminescent device described in the third aspect.

[0033] The display components described in this invention include, but are not limited to, flat panel displays, monitors, medical monitors, televisions, billboards, lights for indoor or outdoor lighting and / or signaling, head-up displays, fully or partially transparent displays, flexible displays, smartphones, tablet computers, tablet phones, wearable devices, smartwatches, laptop computers, digital cameras, portable camcorders, viewfinders, microdisplays, 3D displays, vehicle displays, and taillights.

[0034] Compared with existing technologies, the boron-nitrogen compounds based on dianthracene polycyclic aromatic hydrocarbons of this invention can be used as luminescent materials in electroluminescent devices, effectively improving device efficiency, exhibiting better color purity, and providing better device stability. This invention achieves a comprehensive improvement in device performance by introducing an indole-carbazole rigid unit into the boron-nitrogen core and combining precise design of two molecular structures, HU and H(U)2: For the typical compound 2 with the HU structure, the prepared OLED device has a start-up voltage of 3.8 V, a peak emission wavelength of 453 nm, a spectral half-width of only 26 nm, and a maximum external quantum efficiency of 26.0%, CIE. y With a value as low as 0.064, narrow-band blue light emission is achieved with significantly superior color purity compared to existing materials. For typical H(U)₂ compounds 123 and 131, the device startup voltage is further reduced to 3.4 V, with emission peak wavelengths of 452 nm and 453 nm, respectively, and spectral half-widths of only 19 nm. The maximum external quantum efficiencies are 24.2% and 29.2%, respectively, according to CIE standards. y The values ​​are as low as 0.060 and 0.059, which are closer to the BT.2020 blue light standard. Compared with existing technologies, devices prepared with compound ref-1 (start-up voltage 3.4 V, λ) max 466nm, FWHM 30 nm, EQE max 20.2%, CIE y (0.119) The compound of this invention suppresses nonradiative molecular transitions due to its rigid molecular structure, significantly improving the maximum external quantum efficiency of the device; it promotes hole injection and transport through indole-carbazole / indole-benzothiophene units, reducing the probability of carrier annihilation and achieving low start-up voltage characteristics; at the same time, the rigid units do not introduce additional vibrational modes, and the weak interaction with the host material avoids the formation of excitocomplexes, resulting in a significant narrowing of the full width at half maximum (FWHM) of the spectrum, a blue shift of the emission wavelength, and CIE efficiency. yThe value is significantly reduced, and the color purity is significantly improved. Furthermore, the large π-conjugated system of dianthracene polycyclic aromatic hydrocarbons and the electronic structure regulation advantages of boron-nitrogen doping also endow the material with excellent carrier transport capability and thermal stability, effectively improving the working stability and service life of the device. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the device structure for applying the compounds disclosed in this invention to OLED devices.

[0036] Figure 2 For compound 2 1 H NMR spectrum.

[0037] Figure 3 For compound 2 13 C10 NMR spectrum.

[0038] Figure 4 For compound 123 1 H NMR spectrum.

[0039] Figure 5 For compound 123 13 C10 NMR spectrum.

[0040] Figure 6 For compound 131 1 H NMR spectrum. Detailed Implementation

[0041] The present invention will now be described in further detail with reference to specific embodiments and data. It should be understood that these embodiments are merely illustrative of the invention and are not intended to limit the scope of the invention in any way.

[0042] In the following embodiments, the raw materials involved can be purchased from the market or prepared by conventional methods in the art, and the various processes and methods not described in detail are conventional methods known in the art.

[0043] Figure 1 An OLED device structure 100 is illustrated schematically and non-limitingly. The figures are not necessarily drawn to scale, and some layers may be omitted as needed. Device 100 includes a substrate layer 101, an anode layer 110, a hole injection layer 120, a hole transport layer 130, an electron blocking layer 140, a light-emitting layer 150, a hole blocking layer 160, an electron transport layer 170, an electron injection layer 180, and a cathode layer 190. Device 100 can be fabricated by sequentially depositing the described layers. The properties and functions of each layer, as well as exemplary materials, are described in more detail in columns 6-10 of U.S. Patent 7,279,704B2, the entire contents of which are incorporated herein by reference.

[0044] Material synthesis examples: The preparation methods of the compounds of this invention are not limited. Typical but not limited examples are the following compounds, whose synthetic routes and preparation methods are as follows: Synthesis Example 1: Synthesis of Compound 2 Step 1: Synthesis of Intermediate 1

[0045] In a dry 250 mL two-necked flask, starting material 1 (3.5 g, 1 eq), starting material 2 (5.62 g, 2 eq), sodium tert-butoxide (3.11 g, 2.5 eq), palladium acetate (58 mg, 2%), and tri-tert-butylphosphine tetrafluoroborate (0.15 g, 4%) were added sequentially. After purging with nitrogen three times, 30 mL of toluene was added, and the mixture was heated to 110 °C and reacted overnight. After the reaction was monitored by thin-layer chromatography (TLC), the mixture was cooled to room temperature, extracted with an appropriate amount of water and ethyl acetate, and the organic phase was separated. The organic phase was dried over anhydrous magnesium sulfate, concentrated, and then subjected to column chromatography to give a white solid intermediate 1 (5.9 g, 91% yield).

[0046] Step 2: Synthesis of Intermediate 2

[0047] In a dry 250 mL Schlenk tube, intermediate 1 (5.5 g, 1 eq) was added. After purging with nitrogen three times, 80 mL of ultradry o-dichlorobenzene was added. Boron tribromide (2.11 mL, 2 eq) was slowly added dropwise under an ice-water bath. After slowly returning to room temperature, the temperature was raised to 200 °C and reacted for 20 h. After cooling to room temperature, methanol (80 mL) was slowly added under an ice-water bath to quench the reaction. The reaction solution was concentrated and then subjected to column chromatography to give a yellow solid intermediate 2 (3 g, yield 53%).

[0048] Step 3: Synthesis of Intermediate 3

[0049] In a dry 250 mL two-necked flask, intermediate 2 (3.0 g, 1 eq), starting material 3 (0.79 g, 1 eq), sodium tert-butoxide (1.41 g, 2.5 eq), tris(dibenzylacetone)dipalladium (0.27 g, 2%), and Sphos (0.16 g, 4%) were added sequentially. After purging with nitrogen three times, 50 mL of xylene was added, and the mixture was heated to 150 °C and reacted overnight. After the reaction was completed by TLC monitoring, the mixture was cooled to room temperature, extracted with an appropriate amount of water and dichloromethane, and the organic phase was separated. The organic phase was dried over anhydrous magnesium sulfate, concentrated, and then subjected to column chromatography to give a yellow solid intermediate 3 (3.4 g, 95% yield).

[0050] Step 4: Synthesis of Intermediate 4

[0051] In a dry 250 mL two-necked flask, intermediate 3 (3.0 g, 1 eq), starting material 4 (2.71 g, 2 eq), sodium tert-butoxide (1.41 g, 3 eq), tris(dibenzylacetone)dipalladium (0.27 g, 1%), and Sphos (0.13 g, 2%) were added sequentially. After purging with nitrogen three times, 50 mL of xylene was added, and the mixture was heated to 150 °C and reacted overnight. After the reaction was completed by TLC monitoring, the mixture was cooled to room temperature, extracted with an appropriate amount of water and dichloromethane, and the organic phase was separated. The organic phase was dried over anhydrous magnesium sulfate, concentrated, and then subjected to column chromatography to give intermediate 4 (3.8 g, 91% yield), a yellow solid compound.

[0052] Step 5: Synthesis of Compound 2

[0053] In a dry 150 mL Schlenk tube, intermediate 4 (1.8 g, 1.87 mmol) was added. After purging with nitrogen three times, 30 mL of ultradry o-dichlorobenzene was added. Boron tribromide (0.54 mL, 5.62 mmol) was slowly added dropwise under an ice-water bath. The mixture was slowly cooled to room temperature and then heated to 200 °C for 48 h. After cooling to room temperature, the reaction was quenched by slowly adding methanol (20 mL) under an ice-water bath. The reaction solution was concentrated and then subjected to column chromatography to give a yellow solid compound 2 (1.1 g, 61% yield). Compound 2... 1 H NMR spectrum and 13 The C NMR spectra are as follows: Figure 2 and Figure 3 As shown.

[0054] Synthesis Example 2: Synthesis of Compound 123 Step 1: Synthesis of Intermediate 5

[0055] In a dry 250 mL two-necked flask, starting material 5 (3.5 g, 1.0 eq), starting material 6 (5.6 g, 2.0 eq), sodium tert-butoxide (3.11 g, 2.5 eq), palladium acetate (58 mg, 2%), and Xantphos (0.15 g, 4%) were added sequentially. After purging with nitrogen three times, 50 mL of N,N-dimethylformamide was added, and the mixture was heated to 150 °C and reacted for 12 h. After the reaction was complete as monitored by thin-layer chromatography (TLC), the mixture was cooled to room temperature, extracted with an appropriate amount of water and ethyl acetate, and the organic phase was separated. The organic phase was dried over anhydrous magnesium sulfate, concentrated, and then subjected to column chromatography to give a white solid intermediate 5 (5.9 g, 91% yield).

[0056] Step 2: Synthesis of Intermediate 6

[0057] In a dry 250 mL two-necked flask, intermediate 5 (4.0 g, 1.0 eq), starting material 3 (4.0 g, 3.0 eq), sodium tert-butoxide (3.8 g, 3.5 eq), tris(dibenzylacetone)palladium (0.2 mg, 2%), and Sphos (0.2 g, 4%) were added sequentially. After purging with nitrogen three times, 50 mL of xylene was added, and the mixture was heated to 150 °C and reacted for 12 h. After the reaction was complete as monitored by thin-layer chromatography (TLC), the mixture was cooled to room temperature, extracted with an appropriate amount of water and ethyl acetate, and the organic phase was separated. The organic phase was dried over anhydrous magnesium sulfate, concentrated, and then subjected to column chromatography to give a white solid intermediate 6 (4.8 g, 88% yield).

[0058] Step 3: Synthesis of Intermediate 7

[0059] In a dry 250 mL two-necked flask, intermediate 6 (3.0 g, 1.0 eq), starting material 4 (3.8 g, 2.5 eq), sodium tert-butoxide (1.6 g, 3.0 eq), tris(dibenzylacetone)palladium (0.1 mg, 2%), and Sphos (0.1 g, 4%) were added sequentially. After purging with nitrogen three times, 50 mL of xylene was added, and the mixture was heated to 150 °C and reacted for 12 h. After the reaction was complete as monitored by thin-layer chromatography (TLC), the mixture was cooled to room temperature, extracted with an appropriate amount of water and ethyl acetate, and the organic phase was separated. The organic phase was dried over anhydrous magnesium sulfate, concentrated, and then subjected to column chromatography to give a white solid intermediate 7 (4.8 g, 88% yield).

[0060] Step 4: Synthesis of Compound 123

[0061] In a dry 150 mL Schlenk tube, intermediate 7 (2.0 g, 1.0 eq) was added. After purging with nitrogen three times, 40 mL of ultra-dry o-dichlorobenzene was added. Boron tribromide (1.14 mL, 6 eq) was rapidly added dropwise at room temperature, and the mixture was heated to 200 °C and reacted for 48 h. After the reaction was completed by thin-layer chromatography (TLC), the mixture was cooled to room temperature, filtered through diatomaceous earth, and the filtrate was concentrated and then subjected to column chromatography to give a yellow solid compound 123 (0.8 g, 40% yield). Compound 123... 1 H NMR spectrum and 13 The C NMR spectra are as follows: Figure 4 and Figure 5 As shown.

[0062] Synthesis Example 3: Synthesis of Compound 131 Step 1: Synthesis of Intermediate 8

[0063] In a dry 500 mL three-necked flask, starting material 5 (8.5 g, 1.0 eq), starting material 6 (16.24 g, 1.2 eq), copper powder (10.84 g, 4.0 eq), and potassium carbonate (29.84 g, 5 eq) were added sequentially. After purging with nitrogen three times, 200 mL of ultra-dry o-dichlorobenzene was added, and the mixture was heated to 180 °C and reacted overnight. After the reaction was completed by TLC monitoring, it was cooled to room temperature, filtered through diatomaceous earth, and the filtrate was concentrated and then subjected to column chromatography to obtain a white solid intermediate 8 (10.68 g, yield 64%).

[0064] Step 2: Synthesis of Intermediate 9

[0065] In a dry 500 mL three-necked flask, intermediate 8 (10.68 g, 1 eq), cesium carbonate (26.86 g, 3 eq), terpentine (4.21 g, 1.5 eq), tris(dibenzylacetone)dipalladium (0.12 g, 2%), and tricyclohexylphosphine tetrafluoroborate (0.51 g, 5%) were added sequentially. After purging with nitrogen three times, 105 mL of xylene and 10.5 mL of N,N-dimethylacetamide were added, and the mixture was heated to 150 °C and reacted overnight. After the reaction was complete as monitored by TLC, the mixture was cooled to room temperature, extracted with an appropriate amount of saturated brine and ethyl acetate, and the organic phase was separated. The organic phase was dried over anhydrous magnesium sulfate, concentrated, and then subjected to column chromatography to give intermediate 9 (5.65 g, 70% yield), a yellowish-white solid compound.

[0066] Step 3: Synthesis of Intermediate 10

[0067] In a dry 250 mL three-necked flask, intermediate 2 (2.8 g, 1 eq), intermediate 9 (4.2 g, 2.5 eq), sodium tert-butoxide (1.58 g, 3 eq), tris(dibenzylacetone)dipalladium (0.10 g, 2%), and Sphos (0.22 g, 10%) were added sequentially. After purging with nitrogen three times, 100 mL of xylene was added, and the mixture was heated to 155 °C and reacted overnight. After the reaction was completed by TLC monitoring, the mixture was cooled to room temperature, extracted with an appropriate amount of water and ethyl acetate, and the organic phase was separated. The organic phase was dried over anhydrous magnesium sulfate, concentrated, and then subjected to column chromatography to give intermediate 10 (5.4 g, 94% yield), a white solid compound.

[0068] Step 4: Synthesis of Compound 131

[0069] In a dry 250 mL round-bottom reaction tube, intermediate 10 (4.8 g, 1.0 eq) was added. After purging with nitrogen three times, 80 mL of ultra-dry o-dichlorobenzene was added. Boron tribromide (1.75 mL, 4 eq) was rapidly added dropwise at room temperature. The mixture was stirred at room temperature for 0.5 h, then heated to 100 °C and stirred for 1 h. Finally, the temperature was increased to 180 °C and the reaction was carried out for 48 h. After cooling to room temperature, the reaction solution was quenched by adding 80 mL of ethanol dropwise under ice-water bath conditions. The reaction solution was concentrated and then subjected to column chromatography to finally give a yellow solid compound 3 (110 mg, yield 10%). Compound 131 1 H NMR spectrum as shown Figure 6 As shown.

[0070] Comparative Example 1: Synthesis of compound ref-1 Step 1: Synthesis of Intermediate 11

[0071] In a dry 250 mL two-necked flask, starting material 7 (5 g, 1 eq), starting material 2 (8.36 g, 2 eq), sodium tert-butoxide (5.09 g, 2.5 eq), palladium acetate (85 mg, 2%), and tri-tert-butylphosphine tetrafluoroborate (0.24 g, 4%) were added sequentially. After purging with nitrogen three times, 30 mL of toluene was added, and the mixture was heated to 110 °C and reacted overnight. After the reaction was monitored by thin-layer chromatography (TLC), the mixture was cooled to room temperature, extracted with an appropriate amount of water and ethyl acetate, and the organic phase was separated. The organic phase was dried over anhydrous magnesium sulfate, concentrated, and then subjected to column chromatography to give a white solid intermediate 11 (9 g, 90% yield).

[0072] Step 2: Synthesis of compound ref-1

[0073] In a dry 250 mL Schlenk tube, intermediate 11 (5 g, 1 eq) was added, purged with nitrogen three times, and then 80 mL of ultra-dry o-dichlorobenzene was added. Boron tribromide (8 mL, 2 eq) was slowly added dropwise under an ice-water bath. After slowly returning to room temperature, the temperature was raised to 200 °C and reacted for 20 h. After cooling to room temperature, methanol (80 mL) was slowly added under an ice-water bath to quench the reaction. The reaction solution was concentrated and then subjected to column chromatography to give a yellow solid compound ref-1 (3 g, 60% yield).

[0074] Device Examples: Organic electroluminescent devices prepared based on compounds 2, 123, 131, and Comparative Example 1 of this invention. First, the glass substrate, which has a 120 nm thick indium tin oxide (ITO) anode, is cleaned and then treated with UV ozone and oxygen plasma. After treatment, the substrate is dried in a nitrogen-filled glove box to remove moisture, and then mounted on a substrate holder and placed in a vacuum chamber. The organic layer specified below is applied at a vacuum degree of approximately 10... -8 Under Torr conditions, deposition was performed sequentially on the ITO anode via thermal vacuum at a rate of 0.10 nm / s. Simultaneously, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene (HAT-CN) was deposited as a hole injection layer (HIL) with a thickness of 5 nm; 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline (TAPC) and 4,4',4''-tris(carbazole-9-yl)triphenylamine (TCTA) were deposited as a hole transport layer (HTL) with a thickness of 40 nm; 3,3-bis(carbazole)biphenyl (mCBP) was used as an electron blocking layer (EBL) with a thickness of 10 nm; and 3,3′-(2,5-dimethyl-1,4-phenylene)bis(9-phenyl-9H-carbazole)... p -PhBCzPh) and the dopant material of the present invention, with a mass fraction of 2 wt%, are co-deposited as the light-emitting layer (EML) with a thickness of 30 nm; 2,8-bis(diphenylphospho)dibenzo[b,d]furan (PPF) is used as the hole-blocking layer (HBL) with a thickness of 10 nm; 1,3,5-tris[(3-pyridyl)-3-phenyl]benzene (TmPyPB) is used as the electron transport layer (ETL) with a thickness of 40 nm; 8-hydroxyquinoline-lithium (Liq) is used as the electron injection layer (EIL) with a thickness of 1 nm; and aluminum is used as the cathode with a thickness of 150 nm. The device is then transferred back to the glove box and sealed with a glass cover to complete the device. The material structure used in the device is shown below:

[0075] Table 1 Device structures of device embodiments and comparative examples

[0076] Table 2. Device performance parameters of the device embodiments and comparative examples.

[0077] As can be seen from the device data results in Table 2, this invention achieves significant optimization of blue light emission performance by precisely expanding and structurally fusing the indole-carbazole unit in the boron-nitrogen core. The emission wavelength is significantly blue-shifted to the 452-453 nm range, achieving CIE [missing information]. y The value is as low as 0.059-0.064, with the core value reaching around 0.06, which is very close to the blue light requirements of the BT.2020 ultra-high-definition display standard, breaking through the technical bottleneck of insufficient color purity of traditional boron-nitrogen blue light materials. Compared with Comparative Example 1, the compounds of the present invention exhibit superior overall electroluminescence performance when applied to single-host system devices (Examples 1-3): the device with the HU structure 2 has a startup voltage of 3.8V, while the devices with the H(U)2 structure 123 and 131 have startup voltages as low as 3.4V, which are on par with or even better than the comparative samples. This is because the indole-carbazole / indole-benzothiophene unit, as an electron-rich hole-transporting group, effectively optimizes the energy level arrangement of the molecule, further promotes hole injection and transport efficiency, reduces the energy barrier for carrier injection, and reduces non-radiative annihilation of holes and electrons inside the device, allowing for more efficient recombination of carriers in the luminescent layer. Compared with the maximum external quantum efficiency of 20.2% in Comparative Example 1, the maximum external quantum efficiencies of devices in Examples 1-3 are increased to 26.0%, 24.2%, and 30%, respectively. The 2% increase is due to the fact that this invention relies on the rigid framework of dianthracene fused-ring aromatic hydrocarbons and combines it with the rigid structure design of the indole-carbazole unit, which significantly suppresses the structural relaxation between the ground state and excited state of the molecule, effectively reducing the probability of nonradiative transitions and allowing excitons to release more energy in the form of radiative transitions, thus achieving a significant improvement in luminescence efficiency. Compared with the spectral half-width of 30 nm in Comparative Example 1, the compounds of this invention still exhibit excellent narrow-band blue light emission characteristics in single-host system devices (Examples 1-3), with the half-width narrowed to 19-26 nm. Among them, the compounds 123 and 131 with the H(U)2 structure have a half-width of only 19 nm, and the narrow-band effect is particularly outstanding. This is mainly because the introduction of the rigid unit indole-carbazole does not introduce additional vibrational modes into the molecular system, avoiding spectral broadening caused by molecular vibration. At the same time, the boron-nitrogen fused-ring compounds of this invention and the host material pThe weak intermolecular interactions between -PhBCzPh effectively reduce the probability of excitocomplex formation, fundamentally avoiding the spectral broadening problem caused by excitocomplexes, and ultimately achieving narrow-band, high-color-purity blue light emission. Overall, this invention, through precise molecular structure design, achieves a synergistic improvement in device startup voltage, luminous efficiency, and color purity, exhibiting comprehensive performance far exceeding existing materials in a single host system, and possessing extremely strong industrial application value.

[0078] It should be understood that the various embodiments described herein are merely examples and are not intended to limit the scope of the invention. Therefore, as will be apparent to those skilled in the art, the claimed invention may include variations of the specific embodiments and preferred embodiments described herein. Many of the materials and structures described herein can be substituted with other materials and structures without departing from the spirit of the invention. It should be understood that various theories regarding why the invention works are not intended to be limiting.

[0079] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A boron-nitrogen compound based on dianthracene polycyclic aromatic hydrocarbons, characterized in that, The structure is represented by HU, where H has the structure of Equation 1-1, which is expressed as: The U is selected from a structure having Equation 2, which is expressed as: " "Indicates the location where H and U are connected; on ring 4" "Indicates adjacent substitution; in, X and Y are selected from single bonds, O, S, Se, NR', CR''R''' or SiR''R''', and combinations thereof, each time they appear, either identically or differently. R 1 To R 6 R', R'', and R''' are selected, in the same or different manner, from the group consisting of: hydrogen, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, and substituted or unsubstituted aryloxy groups having 6-30 carbon atoms. Substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted alkynyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms. R 1 To R 6 Each occurrence indicates either single or multiple substitution; Adjacent substituent R 1 To R 6 R', R'', and R''' can be optionally connected to form a ring.

2. The boron-nitrogen compound based on dianthracene polycyclic aromatic hydrocarbons according to claim 1, characterized in that, It has a structure represented by H(U)2, wherein H has the structure of Equation 1-2, which is expressed as: The U is selected from a structure having Equation 2, which is expressed as: " "Indicates the location where H and U are connected; on ring 3" "Indicates adjacent substitution; in, X and Y are selected from single bonds, O, S, Se, NR', CR''R''' or SiR''R''', and combinations thereof, each time they appear, either identically or differently. R 1 R 2 R 4 R 5 R 6 R', R'', and R''' are selected, in the same or different manner, from the group consisting of: hydrogen, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, and substituted or unsubstituted aryloxy groups having 6-30 carbon atoms. Substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted alkynyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms. R 1 To R 6 Each occurrence indicates either single or multiple substitution; Adjacent substituent R 1 To R 6 R', R'', and R''' can be optionally connected to form a ring.

3. A boron-nitrogen compound based on dianthracene polycyclic aromatic hydrocarbons according to claim 1, characterized in that, The rings 1, 2, 3, 4, 5 and 6, when appearing in the same or different ways, are selected from 5-membered unsaturated carbon rings, aromatic rings having 6-30 carbon atoms, or heteroaromatic rings having 3-30 carbon atoms.

4. A boron-nitrogen compound based on dianthracene polycyclic aromatic hydrocarbons according to claim 1, wherein the compound is selected from structures represented by formula I to V: , , , , in, X and Y are selected from single bonds, O, S, Se, NR', CR''R''' or SiR''R''', and combinations thereof, each time they appear, either identically or differently. R 1 To R 6 R', R'', and R''' are selected, in the same or different manner, from the group consisting of: hydrogen, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted heterocycloalkyl groups having 3-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, and substituted or unsubstituted aryloxy groups having 6-30 carbon atoms. Substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted alkynyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carbonyl, carboxylic acid, ester, cyano, isocyano, hydroxyl, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms. R 1 To R 6 Each occurrence indicates either single or multiple substitution; Adjacent substituent R 1 To R 6 R', R'', and R''' can be optionally connected to form a ring.

5. A boron-nitrogen compound based on dianthracene polycyclic aromatic hydrocarbons according to claim 1, characterized in that, The compounds are selected from the following structures and their combinations: structures corresponding to compounds 1 to 190, structures obtained by partially or completely replacing hydrogen in any of the structures corresponding to compounds 1 to 190 with deuterium, and combinations thereof; the structures represented by compounds 1 to 190 respectively correspond to the following structures: 。 6. An electroluminescent device, characterized in that, include: anode, cathode, And an organic layer disposed between the anode and the cathode, the organic layer comprising a compound as described in any one of claims 1 to 5.

7. An electroluminescent device according to claim 6, characterized in that, The organic layer is a light-emitting layer, and the compound is used as a light-emitting material.

8. An electroluminescent device according to claim 6, characterized in that, One or more of the organic layers are formed by deposition or solution methods.

9. An electroluminescent device according to claim 6, characterized in that, The hole injection layer further comprises at least one hole transport material, which includes compounds having triarylamine units, spirodifluorene compounds, pentanebenzene compounds, oligothiophene compounds, oligophenyl compounds, oligophenylenevinylene compounds, oligofluorene compounds, porphyrin complexes, or metal phthalocyanine complexes.

10. A display component, characterized in that, It includes the electroluminescent device as described in any one of claims 6 to 9.

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