Carbonyl-multi-boron nitrogen derivative and application thereof

Abstract

The invention discloses a carbonyl-multi-boron nitrogen derivative and application thereof. The carbonyl-multi-boron nitrogen derivative has a structure as shown in a formula (I). Wherein R, R1, R2, R3, R4, R5 and R6 are respectively and independently represented as alkyl with 1 to 24 carbon atoms, alkoxy with 1 to 24 carbon atoms, alkylamino with 1 to 24 carbon atoms, aryl with 1 to 24 carbon atoms, aryloxy with 1 to 24 carbon atoms or arylamino with 1 to 24 carbon atoms; a, b, c, d, e and f independently represent positive integers from 0 to 5 and do not exceed the highest integers which can be substituted by the substituted benzene ring; and Z1 and Z2 independently represent an alkylene group, an arylene group, an alkyleneamine group, an arylene amine group, a sulfenyl group, a sulfoxide group, a sulfonyl group, a carbonyl group, a selenium bond, a sulfur bond, an ether bond, a single bond, a double bond or do not exist. According to the design scheme, on the premise that the molecular complexity is not increased, the charge distribution of molecules is optimized, and the exciton utilization rate is increased; the environment resistance of the material is enhanced, and the high-color-purity luminescence characteristic is maintained.

Description

Technical Field

[0001] The present invention relates to the technical field of organic electroluminescence, and particularly to a carbonyl-multi-boron nitride derivative and its application. Background Art

[0002] Organic light-emitting diodes (OLEDs) have become the core of the new generation of display and lighting technologies due to their advantages such as high brightness, high energy efficiency, flexibility and bendability. In recent years, thermally activated delayed fluorescence (TADF) materials have received extensive attention in the industrial field because they can efficiently utilize charge carriers and improve the external quantum efficiency (EQE) of devices. Among them, multiple resonance (MR) TADF materials have become important candidates for high-end display applications due to their excellent spectral purity and high exciton utilization efficiency.

[0003] Although existing MR-TADF materials exhibit high photoluminescence quantum yields (PLQY) and narrow-band emission characteristics in a laboratory environment, they still have certain limitations in industrial applications. For example, the singlet-triplet energy gap (ΔE ST ) of some materials is relatively large, which affects the reverse intersystem crossing (RISC) rate and thus reduces the device efficiency. In addition, the complexity of the molecular structure may lead to an increase in synthesis costs and affect large-scale production. At the same time, the chemical stability of some materials is relatively low, and they are prone to degradation under high-temperature and high-humidity environments, which is not conducive to long-term use.

[0004] Current material optimization strategies mainly focus on the modification of the molecular structure to improve its stability, reduce non-radiative losses and improve device lifetime. However, existing modification methods often bring additional process challenges, such as increasing production steps or improving synthesis difficulty. Therefore, how to balance the efficient light-emitting characteristics of materials and the feasibility of industrial production remains a key issue in the development of OLED materials. Summary of the Invention

[0005] To solve at least one of the problems existing in the prior art, the present invention proposes a novel MR-TADF molecular design scheme. By introducing a carbonyl (C=O) as an electron-withdrawing motif, the optoelectronic properties and stability of the material are effectively optimized. Without increasing the molecular complexity, this strategy achieves the following advantages: (1) optimizing the charge distribution of the molecule and improving exciton utilization efficiency; (2) enhancing the environmental resistance of the material and reducing the degradation risk during operation; (3) maintaining the high color purity light-emitting characteristics and being suitable for high-end display applications. The novel MR-TADF materials developed based on this scheme have significant improvements in emission wavelength, spectral stability and device lifetime, can meet the industrialization requirements, and provide a reliable material basis for the next generation of high-efficiency OLED devices. The specific technical solutions are as follows:

[0006] On the one hand, the present invention provides a carbonyl-polyboron nitride derivative, and the carbonyl-polyboron nitride derivative has a structure shown in formula (I):

[0007]

[0008] Wherein, R, R1, R2, R3, R4, R5, R6 each independently represent a C1-C24 alkyl group, a C1-C24 alkoxy group, a C1-C24 alkanamino group, a C1-C24 aryl group, a C1-C24 aryloxy group or a C1-C24 arylamino group;

[0009] a, b, c, d, e, f each independently represent a positive integer from 0 to 5 and do not exceed the highest integer that the substituted benzene ring can be substituted;

[0010] Z1 and Z2 each independently represent an alkylene group, an arylene group, an alkanimino group, an arylimino group, a thio group, a sulfinyl group, a sulfonyl group, a carbonyl group, a selenium bond, a sulfur bond, an ether bond, a single bond, a double bond or do not exist.

[0011] As a preferred embodiment of the carbonyl-polyboron nitride derivative of the present invention, R is hydrogen or an alkyl group.

[0012] As a preferred embodiment of the carbonyl-polyboron nitride derivative of the present invention, the carbonyl-polyboron nitride derivative has a structure shown in formula (II):

[0013]

[0014] Wherein, R1, R2, R3, R4 each independently represent a C1-C24 alkyl group, a C1-C24 alkoxy group, a C1-C24 alkanamino group, a C1-C24 aryl group, a C1-C24 aryloxy group or a C1-C24 arylamino group, a, b, c, d each independently represent a positive integer from 0 to 5 and do not exceed the highest integer that the substituted benzene ring can be substituted, Z1 and Z2 each independently represent an alkylene group, an arylene group, an alkanimino group, an arylimino group, a thio group, a sulfinyl group, a sulfonyl group, a carbonyl group, a selenium bond, a sulfur bond, an ether bond, a single bond, a double bond or do not exist.

[0015] As a preferred embodiment of the carbonyl-polyboron nitride derivative of the present invention, the alkyl group includes but is not limited to methyl, ethyl, propyl, butyl, pentyl or hexyl, etc.;

[0016] The alkoxy group includes but is not limited to methoxy, ethoxy, propoxy, butoxy, pentyloxy or hexyloxy, etc.;

[0017] The alkanamino group includes but is not limited to methylamino, ethylamino, propylamino, butylamino, pentylamino or hexylamino, etc.;

[0018] The aryl group includes, but is not limited to, phenyl, naphthyl, biphenyl, tolyl, ethylphenyl, propylphenyl, butylphenyl, pentylphenyl, hexylphenyl, methoxyphenyl, ethoxyphenyl, propoxyphenyl, butoxyphenyl, pentyloxyphenyl, hexyloxyphenyl, methylaminophenyl, ethylaminophenyl, or propylaminophenyl, etc.;

[0019] The aryloxy group includes, but is not limited to, phenoxy, tolyloxy, ethylphenoxy, propylphenoxy, or butylphenoxy, etc.;

[0020] The arylamino group includes, but is not limited to, anilino, toluidino, ethylanilino, propylanilino, or butylanilino, etc.

[0021] As a preferred embodiment of the carbonyl-polyboron nitride derivative of the present invention, R1 is the same as R4, R2 is the same as R3, R5 is the same as R6, a is the same as d, b is the same as c, and e and f are the same. R1, R2, R3, R4, R5, and R6, as substituents of the present invention, can be mono-substituted, that is, the substituent is connected to the group to be substituted only through one chemical bond, or can be multi-substituted, that is, the substituent is connected to the group to be substituted through at least two chemical bonds. The chemical bond refers to one of a single bond, a double bond, a triple bond, and a coordination bond. When using the multi-substituted method, at least two substitution positions of R1, R2, R3, R4, R5, and R6 are connected to the group to be substituted, and at this time, a ring-forming method is used to connect to the group to be substituted. It can be understood that the substituent described in the present invention refers to a group in which at least one substitution position is connected to the group to be substituted, rather than a group in which only one substitution position is connected to the group to be substituted. By way of example and not limitation, an alkyl group includes an alkylene group.

[0022] As a preferred embodiment of the carbonyl-polyboron nitride derivative of the present invention, the carbonyl-polyboron nitride derivative includes the following structure:

[0023]

[0024]

[0025] As a preferred embodiment of the carbonyl-polyboron nitride derivative of the present invention, the carbonyl-polyboron nitride derivative includes the following structure:

[0026]

[0027]

[0028] As a preferred embodiment of the carbonyl-polyboron nitride derivative of the present invention, the carbonyl-polyboron nitride derivative includes the following structure:

[0029]

[0030]

[0031] On the one hand, the present invention also provides an organic electroluminescent device, comprising the carbonyl-polyboron nitride derivative described in the above technical solution.

[0032] In the organic electroluminescent device of the present invention, the maximum emission peak of the emission spectrum of the device is located at 500 nm - 560 nm.

[0033] Compared with the prior art, the present invention has at least the following beneficial effects:

[0034] The novel MR-TADF molecular design scheme of the present invention effectively optimizes the optoelectronic properties and stability of the material by introducing a carbonyl group (C=O) as an electron-withdrawing motif. This strategy optimizes the charge distribution of the molecule, improves the exciton utilization rate, enhances the environmental resistance of the material, reduces the degradation risk during operation, and maintains the high color purity emission characteristics without increasing the molecular complexity, making it suitable for high-end display applications. The novel MR-TADF materials developed based on this scheme have significant improvements in emission wavelength, spectral stability, and device lifetime, can meet the industrialization requirements, and provide a reliable material basis for the next generation of high-efficiency OLED devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings without creative efforts based on these drawings.

[0036] Figure 1 It is a schematic cross-sectional structure diagram of the organic light-emitting device described in this patent. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined purpose, the following specifically describes the specific embodiments, methods, steps, structures, features, and effects of the polyboron nitride derivative proposed according to the present invention in combination with the drawings and embodiments.

[0038] The foregoing and other technical contents, features, and effects of the present invention will be clearly presented in the following detailed description of the preferred embodiments in conjunction with the reference drawings. Through the description of the specific embodiments, a more in-depth and specific understanding of the technical means and effects adopted by the present invention to achieve the predetermined purpose can be obtained. However, the attached drawings are only for reference and illustration purposes and are not used to limit the present invention.

[0039] The field of organic electroluminescence technology belongs to an interdisciplinary subject. In different sub-disciplines, it is a common phenomenon to use different terms to describe the same concept or phenomenon. Generally, different descriptions can be regarded as having the same meaning without being confused or specifically pointed out in the context. It can be understood that "molecule", "compound", "derivative", "structure", "material", "solid", "dye" can all refer to the carbonyl-polyboron nitride derivative of the present invention, unless the context clearly indicates a difference or is easily understood by those skilled in the art to have a difference. It can be understood that the above terms can refer to the carbonyl-polyboron nitride derivative of the present invention, but it does not necessarily mean that they must refer to it. For example, for "solid", in the embodiments of the present invention, there are multiple expressions of "solid". Some "solids" refer to intermediates, and some refer to the carbonyl-polyboron nitride derivative of the present invention. Whether it refers to the carbonyl-polyboron nitride derivative of the present invention depends on the specific position of the corresponding term in the present invention.

[0040] The "carbonyl-polyboron nitride derivative" of the present invention belongs to the technical field of "boron nitride derivative". The "polyboron nitride derivative" described in the present invention means that there are multiple boron atoms and nitrogen atoms in the derivative structure. Multiple means two or more. More specifically, for the "carbonyl-polyboron nitride derivative" of the present invention, there are at least two boron atoms and at least two nitrogen atoms. The technical field of "boron nitride derivative" not only includes "polyboron nitride derivative", but also includes "boron nitride derivative" with only one boron atom or only one nitrogen atom. It can be understood that at least for the purpose of preparation, it is necessary to understand "boron nitride derivative". For example, some intermediates in the following examples are "boron nitride derivative" rather than "polyboron nitride derivative".

[0041] Regarding the abbreviations and symbols in the present invention, abbreviations that are easily understood by those skilled in the art are used. Some abbreviations are listed and explained as follows:

[0042] Pd2(dba)3 refers to tris(dibenzylideneacetone)dipalladium, cas number: 51364-51-3;

[0043] Pd(amphos)Cl2 refers to dichloro-tert-butyl-(4-dimethylaminophenyl)phosphine palladium(II), cas number: 887919-35-9;

[0044] S-phos refers to 2-dicyclohexylphosphino-2′,6′-dimethoxy-biphenyl, cas number: 657408-07-6;

[0045] t-BuONa refers to sodium tert-butoxide, Toluene refers to toluene solution, o-DCB and dichlorobenzene refer to ortho-dichlorobenzene, Tert-butylbenzene refers to tert-butylbenzene, BBr3 refers to boron tribromide,

[0046] mg means milligram, mmol means millimole, mL means milliliter, Pa means Pascal, wt% means weight percentage, nm means nanometer, ppm means parts per million, FWHM means full width at half maximum, °C means degree Celsius, h means hour, min means minute, rt means room temperature, EQE max refers to the maximum luminous efficiency of the electroluminescent device.

[0047] Synthesis Examples

[0048] Example 1: Synthesis of Compound 1-1

[0049]

[0050] The synthesis route of Compound 1-1 is presented in a general manner as above.

[0051]

[0052] Intermediate M1: 1,3-Dibromo-5-chloro-benzene (5.41 g, 20 mmol), diphenylamine (6.77 g, 40 mmol), Pd(amphos)Cl2 (568.08 mg, 0.8 mmol) and sodium tert-butoxide (7.68 g, 80 mmol) were charged into a sealed flask. The sealed flask was deoxygenated and dry toluene (300 mL) was added. The mixture was stirred at 100 °C for 12 h. After cooling to room temperature, the resulting solution was extracted with dichloromethane / water, and the organic layer was concentrated under vacuum. The residue was purified by silica gel column chromatography to give white solid M1 (8.05 g, 90%).

[0053] Structural Characterization of Intermediate M1: 1 H NMR (500 MHz, Chloroform-d) δ 7.30, 7.30, 7.29, 7.28, 7.28, 7.27, 7.27, 7.26, 7.26, 7.25, 7.25, 7.24, 7.22, 7.21, 7.16, 7.16, 7.15, 7.15, 7.14, 7.14, 7.14, 7.13, 7.08, 7.07, 7.07, 7.06, 7.06, 7.06, 7.05, 7.04, 7.04. MALDI-TOF: Calculated: 446.9807, Found: 446.8706.

[0054]

[0055] Intermediate M2: M1 (4.47 g, 10 mmol), 9,10-dihydroacridine (1.81 g, 10 mmol), Pd2(dba)3 (366.3 mg, 0.4 mmol), S-Phos (328.4 mg, 0.8 mmol) and sodium tert-butoxide (3.84 g, 40 mmol) were charged into a sealed flask. The sealed flask was deoxygenated and dry toluene (300 mL) was added. The mixture was stirred at 180 °C for 12 h. After cooling to room temperature, the resulting solution was extracted with dichloromethane / water, and the organic layer was concentrated under vacuum. The residue was purified by silica gel column chromatography to give a pinkish-white solid M2 (4.73 g, 80%).

[0056] Structural characterization of intermediate M2: 1 H NMR (500 MHz, Chloroform-d) δ 7.29, 7.29, 7.28, 7.28, 7.27, 7.27, 7.26, 7.26, 7.25, 7.21, 7.21, 7.20, 7.19, 7.18, 7.18, 7.16, 7.16, 7.15, 7.14, 7.13, 7.13, 7.13, 7.12, 7.12, 7.12, 7.11, 7.11, 7.11, 7.11, 7.10, 7.10, 7.10, 7.09, 7.09, 7.09, 7.09, 7.08, 7.08, 7.07, 7.06, 7.06, 7.05, 7.04, 6.94, 6.94, 6.94, 6.94, 6.93, 6.93, 6.93, 6.92, 6.53, 6.53, 6.50, 6.50, 6.50, 4.11, 4.10, 4.10. MALDI-TOF: Calculated: 591.7666, Found: 591.7544.

[0057]

[0058] Intermediate M3: A mixture of compound M2 (2.96 g, 5 mmol) and 1,2-dichlorobenzene (20 mL) was charged into a sealed flask. The flask was deoxygenated. Then, BBr3 (2.4 mL, 25 mmol) was added dropwise to the reagent. The mixture was heated to 180 °C and stirred for 24 h. After cooling to room temperature, the mixture was added to ice water. The organic layer was extracted with dichloromethane and then concentrated under reduced pressure. The crude product was purified by silica gel column chromatography to give a bright yellow product M3 (1.82 g, 60%).

[0059] Structural characterization of intermediate M3: 11H NMR (500 MHz, Chloroform-d) δ 7.44, 7.43, 7.42, 7.42, 7.39, 7.38, 7.37, 7.37, 7.31, 7.31, 7.31, 7.30, 7.29, 7.29, 7.29, 7.28, 7.28, 7.28, 7.27, 7.27, 7.26, 7.25, 7.18, 7.17, 7.16, 7.16, 7.14, 7.13, 7.13, 7.12, 7.12, 7.12, 7.12, 7.11, 7.11, 7.11, 7.10, 7.10, 7.10, 7.10, 7.10, 7.09, 7.09, 7.09, 7.09, 7.08, 7.08, 7.07, 7.07, 7.07, 7.07, 7.07, 7.06, 7.05, 7.05, 7.04, 7.03, 6.96, 6.94, 6.93, 6.93, 4.33, 4.33, 4.33, 4.14, 4.14, 4.14. MALDI-TOF: Calculated: 607.3302, Found: 607.3501.

[0060]

[0061] Compound 1-1: Compound M3 (0.61 g, 1 mmol) was dissolved in a mixed DCM solvent (20 mL). After the mixture was cooled to 0 °C, DDQ (0.71 g, 4 mmol) was slowly added. The resulting mixture was then warmed to room temperature and stirred overnight. Saturated sodium bicarbonate solution (50 mL) was added to the mixture, and the organic layer was extracted with dichloromethane and then concentrated under reduced pressure. The crude product was purified by silica gel column chromatography to give Compound 1-1 as an orange-red powder (124.3 mg, 20%).

[0062] Structure characterization of Compound 1-1: 11H NMR (500 MHz, Chloroform-d) δ 8.07, 8.07, 8.06, 8.06, 7.73, 7.73, 7.72, 7.71, 7.44, 7.43, 7.42, 7.42, 7.32, 7.32, 7.31, 7.30, 7.30, 7.30, 7.29, 7.29, 7.29, 7.28, 7.28, 7.27, 7.26, 7.26, 7.22, 7.21, 7.20, 7.20, 7.19, 7.18, 7.16, 7.14, 7.13, 7.13, 7.12, 7.12, 7.12, 7.11, 7.11, 7.11, 7.10, 7.10, 7.10, 7.09, 7.09, 7.07, 7.07, 7.06, 7.05, 7.04, 7.04, 6.93. MALDI-TOF: Calculated: 621.3125, Found: 621.3356.

[0063] Example 2: Synthesis of Compound 1-3

[0064]

[0065] Intermediate M4: 1,3,5-Tribromobenzene (6.30 g, 20 mmol), 9,10-dihydroacridine (10.87 g, 60 mmol), Pd2(dba)3 (366.3 mg, 0.4 mmol), S-Phos (328.4 mg, 0.8 mmol) and sodium tert-butoxide (3.84 g, 40 mmol) were charged into a sealed flask. The sealed flask was deoxygenated and dry toluene (300 mL) was added. The mixture was stirred at 180 °C for 12 h. After cooling to room temperature, the resulting solution was extracted with dichloromethane / water, and the organic layer was concentrated in vacuo. The residue was purified by silica gel column chromatography to give a pinkish-white solid M4 (10.59 g, 86%).

[0066] Structural characterization of Intermediate M4: 1 1H NMR (500 MHz, Chloroform-d) δ 7.22, 7.22, 7.21, 7.20, 7.19, 7.19, 7.16, 7.16, 7.15, 7.14, 7.13, 7.13, 7.12, 7.11, 7.08, 7.07, 7.06, 7.06, 7.05, 7.04, 6.95, 6.94, 6.94, 6.94, 6.93, 6.93, 6.93, 6.92, 6.56, 4.11, 4.10, 4.10. MALDI-TOF: Calculated: 615.7865, Found: 615.7555.

[0067]

[0068] Intermediate M5: A mixture of compound M4 (3.08 g, 5 mmol) and 1,2-dichlorobenzene (20 mL) was charged into a sealed flask. The flask was deoxygenated. Then, BBr3 (2.4 mL, 25 mmol) was added dropwise to the reagent. The mixture was heated to 180 °C and stirred for 24 hours. After cooling to room temperature, the mixture was added to ice water. The organic layer was extracted with dichloromethane and then concentrated under reduced pressure. The crude product was purified by silica gel column chromatography to give a bright yellow product M3 (1.26 g, 40%).

[0069] Structural characterization of intermediate M5: 1 H NMR (500 MHz, Chloroform-d) δ 7.39, 7.38, 7.37, 7.37, 7.23, 7.23, 7.21, 7.21, 7.20, 7.20, 7.17, 7.16, 7.15, 7.15, 7.11, 7.11, 7.10, 7.10, 7.10, 7.09, 7.09, 7.09, 7.08, 7.08, 7.07, 7.07, 7.07, 7.07, 6.96, 6.95, 6.94, 6.94, 6.94, 6.93, 6.93, 6.92, 6.92, 4.33, 4.33, 4.33, 4.32, 4.32, 4.14, 4.14, 4.14. MALDI-TOF: Calculated: 631.3865, Found: 631.7555.

[0070]

[0071] Compound 1-3: Compound M5 (0.95 mg, 1.5 mmol) was dissolved in a mixed solvent of DCM (20 mL). After the mixture was cooled to 0 °C, DDQ (0.71 g, 4 mmol) was slowly added. Then the resulting mixture was warmed to room temperature and stirred overnight. Saturated sodium bicarbonate solution (50 mL) was added to the mixture, and the organic layer was extracted with dichloromethane and then concentrated under reduced pressure. The crude product was purified by silica gel column chromatography to give an orange-red powder of compound 1-3 (116.2 mg, 12%).

[0072] Structural characterization of compound 1-3: 11H NMR (500 MHz, Chloroform-d) δ 8.07, 8.07, 8.06, 8.06, 7.73, 7.73, 7.72, 7.71, 7.39, 7.38, 7.37, 7.37, 7.23, 7.23, 7.21, 7.21, 7.20, 7.20, 7.19, 7.18, 7.17, 7.16, 7.16, 7.15, 7.15, 7.11, 7.11, 7.10, 7.10, 7.10, 7.09, 7.09, 7.09, 7.08, 7.08, 7.07, 7.07, 6.96, 6.95, 6.94, 6.94, 6.94, 6.93, 6.93, 6.92, 6.92, 4.32, 4.32, 4.32. MALDI-TOF: Calculated: 645.3265, Found: 645.9155.

[0073] Example 3: Synthesis of Compound 1-15

[0074]

[0075] Compound 1-15: Compound 1-3 (645.3 mg, 1 mmol) was dissolved in a mixed solvent of DCM (20 mL). After the mixture was cooled to 0 °C, DDQ (0.71 g, 4 mmol) was slowly added. Then the resulting mixture was warmed to room temperature and stirred overnight. Saturated sodium bicarbonate solution (50 mL) was added to the mixture, and the organic layer was extracted with dichloromethane and then concentrated under reduced pressure. The crude product was purified by silica gel column chromatography to obtain Compound 1-15 as a red powder (53.9 mg, 8%).

[0076] Structure characterization of Compound 1-15: 1 1H NMR (500 MHz, Chloroform-d) δ 8.08, 8.08, 8.06, 8.06, 8.03, 8.03, 8.02, 8.02, 8.02, 8.02, 8.01, 8.01, 7.73, 7.73, 7.72, 7.72, 7.68, 7.68, 7.67, 7.66, 7.41, 7.41, 7.39, 7.39, 7.38, 7.38, 7.37, 7.36, 7.35, 7.35, 7.19, 7.18, 7.18, 7.17, 7.16, 7.15, 6.99, 6.98, 6.97, 6.97, 6.96, 6.95, 6.92. MALDI-TOF: Calculated: 673.5616, Found: 673.6516.

[0077] Example 4: Synthesis of Compound 1-18

[0078]

[0079] Intermediate M6: Aniline (3.73 g, 40 mmol), 2-bromo-9,9'-spirobi[9H-fluorene] (15.81 g, 40 mmol), Pd(amphos)Cl2 (568.08 mg, 0.8 mmol) and sodium tert-butoxide (7.68 g, 80 mmol) were charged into a sealed flask. The sealed flask was deoxygenated and dry toluene (300 mL) was added. The mixture was stirred at 100 °C for 12 hours. After cooling to room temperature, the resulting solution was extracted with dichloromethane / water, and the organic layer was concentrated under vacuum. The residue was purified by silica gel column chromatography to give white solid M6 (14.34 g, 88%).

[0080] Structural characterization of intermediate M6: 1 H NMR (500 MHz, Chloroform-d) δ 7.85, 7.84, 7.83, 7.83, 7.66, 7.65, 7.39, 7.39, 7.38, 7.38, 7.37, 7.36, 7.35, 7.35, 7.34, 7.33, 7.32, 7.32, 7.32, 7.31, 7.31, 7.30, 7.30, 7.30, 7.29, 7.29, 7.29, 7.28, 7.25, 7.25, 7.24, 7.23, 7.23, 7.23, 7.22, 7.22, 7.21, 7.17, 7.17, 7.16, 7.16, 7.10, 7.09, 7.09, 7.09, 7.08, 7.08, 7.07, 7.07, 6.97, 6.97, 6.96, 6.96, 6.95, 6.95, 6.94, 6.94, 6.93, 6.82, 6.82, 6.81, 6.80, 6.75, 6.75, 6.74, 6.74, 6.68, 6.68, 6.64. MALDI-TOF: Calculated: 407.5156, Found: 407.6895.

[0081]

[0082] Intermediate M7: 1,3-Dibromo-5-chloro-benzene (5.41 g, 20 mmol), M6 (16.30 g, 40 mmol), Pd(amphos)Cl2 (568.08 mg, 0.8 mmol) and sodium tert-butoxide (7.68 g, 80 mmol) were charged into a sealed flask. The sealed flask was deoxygenated and dry toluene (300 mL) was added. The mixture was stirred at 100 °C for 12 h. After cooling to room temperature, the resulting solution was extracted with dichloromethane / water, and the organic layer was concentrated under vacuum. The residue was purified by silica gel column chromatography to give white solid M7 (16.62 g, 90%).

[0083] Structural characterization of intermediate M7: 1 H NMR (500 MHz, Chloroform-d) δ 7.85, 7.84, 7.83, 7.83, 7.65, 7.64, 7.39, 7.39, 7.38, 7.37, 7.36, 7.36, 7.35, 7.35, 7.33, 7.33, 7.31, 7.31, 7.30, 7.30, 7.29, 7.29, 7.29, 7.29, 7.28, 7.28, 7.27, 7.27, 7.27, 7.26, 7.26, 7.26, 7.25, 7.25, 7.24, 7.24, 7.24, 7.24, 7.23, 7.23, 7.23, 7.22, 7.11, 7.11, 7.11, 7.11, 7.11, 7.10, 7.10, 7.10, 7.09, 7.09, 7.08, 7.08, 7.08, 6.92, 6.92, 6.88, 6.87, 6.86, 6.86, 6.81, 6.81, 6.80, 6.80. MALDI-TOF: Calculated: 923.5645, Found: 923.8245.

[0084]

[0085] Intermediate M8: M7 (9.24 g, 10 mmol), 9,10-Dihydroacridine (1.81 g, 10 mmol), Pd2(dba)3 (366.3 mg, 0.4 mmol), S-Phos (328.4 mg, 0.8 mmol) and sodium tert-butoxide (3.84 g, 40 mmol) were charged into a sealed flask. The sealed flask was deoxygenated and dry toluene (300 mL) was added. The mixture was stirred at 180 °C for 12 h. After cooling to room temperature, the resulting solution was extracted with dichloromethane / water, and the organic layer was concentrated under vacuum. The residue was purified by silica gel column chromatography to give pinkish-white solid M8 (8.55 g, 80%).

[0086] Structural characterization of intermediate M8: 1H NMR (500 MHz, Chloroform-d) δ 7.85, 7.84, 7.83, 7.83, 7.65, 7.64, 7.39, 7.39, 7.38, 7.37, 7.36, 7.36, 7.36, 7.34, 7.34, 7.33, 7.33, 7.31, 7.31, 7.30, 7.30, 7.29, 7.29, 7.29, 7.29, 7.28, 7.28, 7.27, 7.27, 7.27, 7.26, 7.26, 7.25, 7.25, 7.25, 7.24, 7.24, 7.24, 7.23, 7.23, 7.23, 7.22, 7.22, 7.21, 7.20, 7.14, 7.14, 7.13, 7.13, 7.11, 7.11, 7.11, 7.10, 7.10, 7.10, 7.10, 7.10, 7.09, 7.09, 7.08, 7.08, 7.08, 7.07, 7.06, 6.94, 6.93, 6.93, 6.93, 6.92, 6.92, 6.92, 6.91, 6.89, 6.89, 6.88, 6.88, 6.87, 6.87, 6.83, 6.83, 6.82, 6.81, 6.67, 6.67, 6.67, 6.66, 6.66, 4.11, 4.10, 4.10. MALDI-TOF: Calculated: 1068.3456, Found: 1068.6946.

[0087]

[0088] Intermediate M9: A mixture of compound M8 (5.34 g, 5 mmol) and 1,2-dichlorobenzene (20 mL) was charged into a sealed flask. The flask was deoxygenated. Then, BBr3 (2.4 mL, 25 mmol) was added dropwise to the reagent. The mixture was heated to 180 °C and stirred for 24 hours. After cooling to room temperature, the mixture was added to ice water. The organic layer was extracted with dichloromethane and then concentrated under reduced pressure. The crude product was purified by silica gel column chromatography to give a bright yellow product M9 (2.71 g, 50%).

[0089] Structural characterization of intermediate M9: 11H NMR (500 MHz, Chloroform-d) δ 7.85, 7.84, 7.83, 7.83, 7.66, 7.64, 7.43, 7.43, 7.41, 7.41, 7.39, 7.39, 7.39, 7.38, 7.38, 7.37, 7.37, 7.37, 7.36, 7.36, 7.36, 7.34, 7.34, 7.33, 7.33, 7.31, 7.31, 7.30, 7.30, 7.29, 7.29, 7.29, 7.29, 7.28, 7.28, 7.27, 7.27, 7.27, 7.27, 7.26, 7.26, 7.25, 7.25, 7.19, 7.19, 7.18, 7.18, 7.09, 7.09, 7.08, 7.08, 7.08, 7.07, 7.07, 7.07, 7.07, 7.06, 7.06, 7.05, 7.05, 7.03, 7.03, 6.97, 6.96, 6.94, 6.94, 6.94, 6.92, 6.89, 6.89, 6.88, 6.87, 6.83, 6.83, 6.82, 6.81, 4.33, 4.33, 4.33, 4.14, 4.14, 4.14. MALDI-TOF: Calculated: 1083.3766, Found: 1083.9485.

[0090]

[0091] Compound 1-18: Compound M9 (1.08 mg, 1 mmol) was dissolved in a DCM mixed solvent (20 mL). After the mixture was cooled to 0 °C, DDQ (0.71 g, 4 mmol) was slowly added. Then the resulting mixture was warmed to room temperature and stirred overnight. Saturated sodium bicarbonate solution (50 mL) was added to the mixture, and the organic layer was extracted with dichloromethane and then concentrated under reduced pressure. The crude product was purified by silica gel column chromatography to give Compound 1-3 as an orange-red powder (164.7 mg, 15%).

[0092] Structure characterization of Compound 1-18: 1¹H NMR (500 MHz, Chloroform-d) δ 8.07, 8.06, 8.05, 8.05, 7.85, 7.84, 7.83, 7.83, 7.72, 7.72, 7.70, 7.70, 7.66, 7.64, 7.43, 7.43, 7.41, 7.41, 7.39, 7.39, 7.38, 7.37, 7.36, 7.36, 7.36, 7.34, 7.34, 7.33, 7.33, 7.31, 7.31, 7.30, 7.30, 7.29, 7.29, 7.29, 7.29, 7.28, 7.28, 7.27, 7.27, 7.27, 7.27, 7.26, 7.26, 7.25, 7.25, 7.21, 7.19, 7.19, 7.19, 7.18, 7.18, 7.18, 7.07, 7.06, 7.05, 7.05, 7.04, 7.03, 6.94, 6.94, 6.92, 6.89, 6.89, 6.88, 6.87, 6.83, 6.83, 6.82, 6.81. MALDI-TOF: Calculated: 1097.8946, Found: 1097.4186.

[0093] Example 5: Synthesis of Compound 2-1

[0094]

[0095] Intermediate M10: 1,3-Dibromo-5-chloro-benzene (5.41 g, 20 mmol), 4,4'-dimethyl-diphenylamine (7.89 g, 40 mmol), Pd(amphos)Cl2 (568.08 mg, 0.8 mmol) and sodium tert-butoxide (7.68 g, 80 mmol) were charged into a sealed flask. The sealed flask was deoxygenated and dry toluene (300 mL) was added. The mixture was stirred at 100 °C for 12 h. After cooling to room temperature, the resulting solution was extracted with dichloromethane / water, and the organic layer was concentrated under vacuum. The residue was purified by silica gel column chromatography to give white solid M10 (9.06 g, 90%).

[0096] Structural Characterization of Intermediate M10: 1 ¹H NMR (500 MHz, Chloroform-d) δ 7.32, 7.31, 7.31, 7.30, 7.29, 7.06, 7.05, 7.04, 7.03, 2.35. MALDI-TOF: Calculated: 503.6412, Found: 503.0945.

[0097]

[0098] Intermediate M11: Charge M10 (5.03 g, 10 mmol), 9,10-dihydroacridine (1.81 g, 10 mmol), Pd2(dba)3 (366.3 mg, 0.4 mmol), S-Phos (328.4 mg, 0.8 mmol) and sodium tert-butoxide (3.84 g, 40 mmol) into a sealed flask. Deoxygenate the sealed flask and add dry toluene (300 mL). Stir the mixture at 180 °C for 12 hours. After cooling to room temperature, the resulting solution is extracted with dichloromethane / water, and the organic layer is concentrated under vacuum. The residue is purified by silica gel column chromatography to obtain a pinkish-white solid M2 (5.18 g, 80%).

[0099] Structural characterization of intermediate M11: 1 H NMR (500 MHz, Chloroform-d) δ 7.21, 7.21, 7.20, 7.19, 7.18, 7.18, 7.17, 7.17, 7.15, 7.15, 7.14, 7.14, 7.12, 7.12, 7.10, 7.10, 7.09, 7.08, 7.08, 7.08, 7.08, 7.07, 7.06, 7.06, 7.05, 7.05, 7.05, 7.04, 7.04, 7.04, 7.03, 7.03, 6.94, 6.94, 6.94, 6.94, 6.94, 6.93, 6.93, 6.93, 6.92, 6.53, 6.53, 6.50, 6.50, 6.50, 4.11, 4.10, 4.10, 2.34, 2.34. MALDI-TOF: Calculated: 647.8765, Found: 647.1564.

[0100]

[0101] Intermediate M12: Charge a mixture of compound M2 (3.24 g, 5 mmol) and 1,2-dichlorobenzene (20 mL) into a sealed flask. Deoxygenate the flask. Then, add BBr3 (2.4 mL, 25 mmol) dropwise to the reagent. Heat the mixture to 180 °C and stir for 24 hours. After cooling to room temperature, add the mixture to ice water. Extract the organic layer with dichloromethane, and then concentrate it under reduced pressure. Purify the crude product by silica gel column chromatography to obtain a bright yellow product M12 (1.99 g, 60%).

[0102] Structural characterization of intermediate M12: 11H NMR (500 MHz, Chloroform-d) δ 7.39, 7.38, 7.37, 7.37, 7.25, 7.24, 7.15, 7.14, 7.14, 7.13, 7.13, 7.13, 7.13, 7.09, 7.09, 7.08, 7.08, 7.08, 7.07, 7.07, 7.07, 7.07, 7.07, 7.06, 7.05, 7.04, 7.04, 6.96, 6.94, 6.93, 6.93, 4.33, 4.33, 4.33, 4.14, 4.14, 4.14, 2.43, 2.43, 2.34. MALDI-TOF: Calculated: 663.4489, Found: 663.4862.

[0103]

[0104] Compound 2-1: Compound M12 (0.66 g, 1 mmol) was dissolved in a mixed solvent of DCM (20 mL). After the mixture was cooled to 0 °C, DDQ (0.71 g, 4 mmol) was slowly added. Then the resulting mixture was warmed to room temperature and stirred overnight. Saturated sodium bicarbonate solution (50 mL) was added to the mixture, and the organic layer was extracted with dichloromethane and then concentrated under reduced pressure. The crude product was purified by silica gel column chromatography to obtain Compound 2-1 as an orange-red powder (169.4 mg, 25%).

[0105] Structure characterization of Compound 2-1: 1 1H NMR (500 MHz, Chloroform-d) δ 8.08, 8.07, 8.06, 8.06, 7.73, 7.73, 7.72, 7.72, 7.25, 7.24, 7.20, 7.18, 7.17, 7.15, 7.15, 7.14, 7.14, 7.13, 7.13, 7.13, 7.13, 7.08, 7.07, 7.06, 7.05, 7.04, 7.04, 6.93, 2.43, 2.43, 2.34. MALDI-TOF: Calculated: 677.4256, Found: 677.5156.

[0106] Device Example

[0107] General preparation method of device example

[0108] Use 110 nm thick indium tin oxide (ITO) glass as Substrate 1. After washing the glass substrate with detergent, deionized water, and isopropyl alcohol, surface activation treatment was carried out by ultraviolet ozone. Each layer was vacuum-evaporated on the washed and activated substrate by vacuum evaporation method to make a cross-sectional view as shown in Figure 1The light-emitting area shown is 0.09 cm 2 of the organic electroluminescent device. The specific steps are as follows:

[0109] First, introduce the aforementioned glass substrate into a vacuum evaporation chamber and reduce the pressure to 1×10 -4 Pa. Then, deposit each functional layer on the substrate 1 in sequence, which are a hole transport layer 2, an electron blocking layer 3, an exciton blocking layer 4, a light-emitting layer 5, an electron transport layer 6, an electron injection layer 7, and a cathode layer 8. Specifically, deposit 30 nm thick 1,1-bis[4-[N,N-bis(p-tolyl)amino]phenyl]cyclohexane (TAPC) as the hole transport layer (HTL) 2, 10 nm thick 4,4',4”-tris(carbazol-9-yl)triphenylamine (TCTA) as the hole blocking layer (HBL) 3, 10 nm thick N,N'-dicarbazolyl-3,5-benzene (mCP) as the exciton blocking layer (EBL) 4, 25 nm thick of the compound of the present invention doped with 1 wt% of 2-(9,9'-spirobifluorene-3-yl)-4,6-diphenyl-1,3,5-triazine (SF3-TRZ) as the light-emitting layer 5 (wt% represents the doping ratio of the compound of the present invention), 35 nm thick 3,3'-[5'-[3-(3-pyridyl)phenyl][1,1':3',1”-terphenyl]-3,3”-diyl]dipyridine (TmPyPb) as the electron transport layer 6, and 1 nm thick lithium fluoride (LiF) as the electron injection layer 7. Each of the organic materials is vacuum deposited into a film by resistance heating, and the film formation rate is Finally, configure a metal mask in a manner orthogonal to the ITO stripes to form the cathode layer 8 with a film thickness of 100 nm, and then seal the device in a nitrogen atmosphere glove box with a water and oxygen concentration of 1 ppm or less. The film thicknesses in the examples are measured with a stylus film thickness gauge (DEKTAK). Sealing uses a glass sealing cover and an epoxy ultraviolet curable resin (manufactured by Nagase ChemteX Corporation) for the aforementioned film-forming substrate.

[0110] Apply a direct current to the prepared organic electroluminescent device, use a Hamamatsu C9920-02 integrating sphere to measure the luminous efficiency, and use a computer-controlled Keithley 2400 digital source meter to measure the current-voltage characteristics.

[0111] Device Experimental Example - 1

[0112] Prepare a device example using a general preparation method. Among them, select compound 1-1 as the light-emitting material to obtain the corresponding device performance. The maximum emission peak of the light-emitting device is 530 nm, and the maximum luminous efficiency is 36.2%.

[0113] Device Experimental Example - 2

[0114] Device examples were prepared using a general preparation method. Among them, compound 1-7 was selected as the luminescent material to obtain the corresponding performance of the evaporation-type device. The maximum emission peak of the light-emitting device was 529 nm, and the maximum luminous efficiency was 36.7%.

[0115] Device Experimental Example-3

[0116] Device examples were prepared using a general preparation method. Among them, compound 1-16 was selected as the luminescent material to obtain the corresponding performance of the evaporation method device. The maximum emission peak of the light-emitting device was 534 nm, and the maximum luminous efficiency was 36.7%.

[0117] Device Experimental Example-4

[0118] Device examples were prepared using a general preparation method. Among them, compound 1-18 was selected as the luminescent material to obtain the corresponding performance of the evaporation method device. The maximum emission peak of the light-emitting device was 538 nm, and the maximum luminous efficiency was 35.2%.

[0119] Device Experimental Example-5

[0120] Device examples were prepared using a general preparation method. Among them, compound 2-1 was selected as the luminescent material to obtain the corresponding performance of the evaporation method device. The maximum emission peak of the light-emitting device was 532 nm, and the maximum luminous efficiency was 37.3%.

[0121] The green electroluminescent device of the present invention refers to an emission spectrum in which the maximum emission peak of the device is located at 500-560 nm, preferably an emission spectrum in which the emission peak is located at 510-545 nm, and more preferably an emission spectrum in which the emission peak is located at 515-540 nm. Those skilled in the art can understand that the maximum emission peak does not have a strict correspondence with the specific emission color. Due to the difference in chemical structure, when the carbonyl-polyboron nitride derivative of the present invention is prepared into a device, the light emission of the device may have an emission spectrum biased towards green or an emission spectrum slightly yellowish green. As long as its maximum emission peak is located at 500-560 nm, it belongs to the green light considered by the present invention, and the corresponding electroluminescent devices all belong to the protection scope of the present invention. Those skilled in the art can understand that the maximum emission peak of the emission spectrum of the carbonyl-polyboron nitride compound of the present invention in solution is different from the maximum emission peak in the device, and the maximum emission peak of the emission spectrum in solution is blue-shifted compared to the maximum emission peak of the device emission spectrum.

[0122] The carbonyl-polyboron nitride compound of the present invention maintains a high photoluminescence quantum efficiency. By way of example but not limitation, the photoluminescence efficiency of compound 1-1 is 95%, and the photoluminescence efficiency of compound 2-1 is 97%.

[0123] There are publicly reported two light-emitting devices with similar structures, compound B-1 [1]The maximum luminous efficiency of the device is 18.3%, the maximum emission peak of the emission spectrum is 460 nm, and the CIE is (0.13, 0.11). Compound B-2 [2] The maximum luminous efficiency of the device is 24.2%, the maximum emission peak of the emission spectrum is 446 nm, and the CIE is (0.15, 0.10). The device efficiency of the carbonyl-polyboron nitride compound embodiments of the present invention is significantly better than that of the devices using polyboron nitride and multi-atom center compounds.

[0124]

[0125] Using the carbonyl-polyboron nitride derivatives of the present invention, the synthesis route has a low cost, has a high device efficiency, and the EQE of the device embodiments max are all greater than 35%.

[0126] In the exemplary device designs of the present invention, the number of layers in the evaporation method and the solution method is different. Those skilled in the art can understand that the number of layers in the evaporation method and the solution method can be the same or different. The lack of a hole injection layer in the device design does not mean that the device design does not consider the hole injection function, but rather that the hole transport layer simultaneously provides the hole injection and hole transport functions. It can be understood that the light-emitting layer also has a hole transport function, otherwise the light-emitting layer would not be able to emit light. As a description of different functional layers, whether it is the light-emitting layer, the transport layer or other layers, it describes the main function but not all functions. Similarly, as a device of the present invention, the functional layer can be one layer or multiple layers.

[0127] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The present invention will not be limited to the embodiments shown herein, but only needs to conform to the principles and characteristics disclosed herein.

Claims

1. A carbonyl-polyboron nitride derivative, characterized in that, The carbonyl-polyboron nitride derivative has a structure shown in formula (I): Wherein, R, R1, R2, R3, R4, R5, R6 each independently represent a C1-C24 alkyl group, a C1-C24 alkoxy group, a C1-C24 alkylamino group, a C1-C24 aryl group, a C1-C24 aryloxy group or a C1-C24 arylamino group; a, b, c, d, e, f each independently represent a positive integer from 0 to 5 and do not exceed the highest integer that the substituted benzene ring can be substituted; Z1, Z2 each independently represent an alkylene group, an arylene group, an alkylimino group, an arylimino group, a thio group, a sulfinyl group, a sulfonyl group, a carbonyl group, a selenium bond, a sulfur bond, an ether bond, a single bond, a double bond or do not exist.

2. The carbonyl-polyboron nitride derivative according to claim 1, characterized in that, The R is hydrogen or an alkyl group.

3. The carbonyl-polyboron nitride derivative according to claim 2, wherein The carbonyl-polyboron nitride derivative has a structure shown in formula (II): Wherein, R1, R2, R3, R4 each independently represent a C1-C24 alkyl group, a C1-C24 alkoxy group, a C1-C24 alkylamino group, a C1-C24 aryl group, a C1-C24 aryloxy group or a C1-C24 arylamino group; a, b, c, d each independently represent a positive integer from 0 to 5 and do not exceed the highest integer that the substituted benzene ring can be substituted; Z1, Z2 each independently represent an alkylene group, an arylene group, an alkylimino group, an arylimino group, a thio group, a sulfinyl group, a sulfonyl group, a carbonyl group, a selenium bond, a sulfur bond, an ether bond, a single bond, a double bond or do not exist.

4. The carbonyl-polyboron nitride derivative according to any one of claims 1-3, characterized in that, The alkyl group is a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or a hexyl group; The alkoxy group is a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group or a hexyloxy group; The alkylamino group is a methylamino group, an ethylamino group, a propylamino group, a butylamino group, a pentylamino group or a hexylamino group; The aryl group is a phenyl group, a naphthyl group, a biphenyl group, a tolyl group, an ethylphenyl group, a propylphenyl group, a butylphenyl group, a pentylphenyl group, a hexylphenyl group, a methoxyphenyl group, an ethoxyphenyl group, a propoxyphenyl group, a butoxyphenyl group, a pentyloxyphenyl group, a hexyloxyphenyl group, a methylaminophenyl group, an ethylaminophenyl group or a propylaminophenyl group; The aryloxy group is a phenoxy group, a tolyloxy group, an ethylphenoxy group, a propylphenoxy group or a butylphenoxy group; The arylamino group is an anilino group, a toluidino group, an ethylanilino group, a propylanilino group or a butylanilino group.

5. The carbonyl-polyboron nitride derivative according to claim 1, characterized in that, The R1 is the same as R4, R2 is the same as R3, R5 is the same as R6, a is the same as d, b is the same as c, and e and f are the same.

6. The carbonyl-polyboron nitride derivative according to any one of claims 1-3, characterized in that, The carbonyl-polyboron nitride derivative has one of the following structures:

7. The carbonyl-polyboron nitride derivative according to any one of claims 1-3, characterized in that, Has one of the following structures:

8. The carbonyl-polyboron nitride derivative according to claim 1, characterized in that, Has one of the following structures:

9. An organic electroluminescent device, characterized in that, Includes the carbonyl-polyboron nitride derivative according to any one of claims 1-8.

10. The organic electroluminescent device according to claim 9, wherein The maximum emission peak of the emission spectrum of the device is located at 500 nm - 560 nm.

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