Six-membered and seven-membered boron-nitrogen heterocyclic derivative based on heavy atom fusion donor as well as preparation method and application of six-membered and seven-membered boron-nitrogen heterocyclic derivative

Abstract

The invention belongs to the field of preparation and application of organic photoelectric materials, and particularly relates to a six-membered and seven-membered boron-nitrogen heterocyclic derivative based on a heavy atom fusion donor, a preparation method and application. The compound has a structure of at least one of general formulas A-1, A-2, B-1 and B-2. The reverse intersystem crossing rate of the material is greatly improved based on the heavy atom effect, the unique fusion donor effect has fine and adjustable electron donating ability, large-range regulation and control of emission wavelength and narrowing of the half-peak width of the heavy atom material are achieved, and the material has good application prospects. When the organic light-emitting molecule is used as a light-emitting material or a sensitizer light-emitting material to be applied to a light-emitting layer structure of an organic light-emitting diode (OLED) device, controllable adjustment in a wavelength range of 450nm to 490nm can be realized, and dark blue light and blue-green light OLED devices with relatively high device efficiency and color purity are obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of organic photoelectric materials, and in particular relates to a six-membered and seven-membered boron nitrogen heterocyclic derivative based on a heavy atom fusion donor, a preparation method and an application thereof. Background Art

[0002] With the continuous development of display technology, organic electroluminescent technology (OLED) has gradually attracted attention due to its outstanding advantages such as self-luminescence, fast response speed, and flexible foldability. At the same time, with the continuous development of OLED-related technologies and the continuous improvement of consumers' requirements for light color purity, the design strategy of thermally activated delayed fluorescence (TADF) emitters based on multi-resonance (MR) skeleton peripheral modification and fusion skeleton extension has been widely developed. In addition, in the design of device structure, TADF or phosphorescent materials are often used as sensitizers to increase the exciton utilization channel, thereby reducing the annihilation process of triplet excitons and achieving efficient utilization of excitons.

[0003] With the continuous development of OLED technology, today's OLED display industry has put forward higher requirements on resolution, color purity, device power consumption, device life, etc. However, compared with conventional TADF emitters, MR-TADF emitters usually exhibit a relatively small reverse gap crossing rate (k RISC ), usually about 10 2 ~10 4 s -1 , which results in a generally long delayed fluorescence lifetime. At high concentrations, triplet exciton annihilation is likely to occur, resulting in a serious efficiency roll-off and poor luminescence performance of narrow-band light-emitting devices. Although adding heavy atoms (oxygen, sulfur, selenium, tellurium atoms, etc.) to MR-TADF can effectively increase its k RISC However, the introduction of heavy atoms will inevitably cause the MR-TADF material to lose its narrow emission characteristics and cause the light color to red shift. So far, heavy atom blue MR-TADF materials with narrow half-width characteristics are still very rare. At the same time, almost all boron nitrogen-based MR-TADF materials inherit the initial triangular ene structure, which greatly limits the diversity of molecular design strategies. Therefore, OLED heavy atom blue light emitting materials and sensitizers need to be further developed and expanded. Summary of the invention

[0004] The purpose of the present invention is to provide a six-membered and seven-membered boron nitrogen heterocyclic derivative based on a heavy atom fusion donor, a preparation method and an application. Based on the heavy atom effect, the reverse intersystem crossing rate of the material can be greatly improved. The unique fusion donor effect has a finely adjustable electron donation ability, which can achieve a wide range of control of the emission wavelength and narrow the half-width of the heavy atom material.

[0005] To achieve the above objectives, according to one aspect of the present invention, a six-membered and seven-membered boron nitrogen heterocyclic derivative based on a heavy atom fusion donor is provided, and the general structural formula of the six-membered and seven-membered boron nitrogen heterocyclic derivative based on a heavy atom fusion donor is shown in Formulas A-1, A-2, B-1, and B-2:

[0006]

[0007] Wherein, R1, R2, and R3 are each independently selected from any one of hydrogen, deuterium, methyl, tert-butyl, an aromatic amine group having 6 to 24 carbon atoms or its derivatives, an aromatic amine heterocyclic group having 12 to 24 carbon atoms or its derivatives;

[0008] Ar is selected from any one of hydrogen, deuterium, methyl, monophenyl group, biphenyl group, naphthalene group, anthracene group, carbazole group, phenylamino group, acridine group, phenoxazine group, phenothiazine group, and oxazine group;

[0009] X is selected from any one of carbon, oxygen, sulfur, selenium and tellurium atoms.

[0010] Preferably, R1, R2, and R3 are each independently selected from any one of hydrogen, deuterium, methyl, tert-butyl, diphenylamino, carbazolyl, phenothiazinyl, phenoxazinyl, 9,10-dihydroacridinyl, 9,9-diphenylacridinyl, 9,9-dimethylacridinyl, diphenylamino derivatives, carbazolyl derivatives, 9,10-dihydroacridinyl derivatives, 9,9-diphenylacridinyl derivatives, or 9,9-dimethylacridinyl derivatives.

[0011] Preferably, Ar is selected from any one of hydrogen, deuterium, methyl, monobenzene group or its derivatives, biphenyl group or its derivatives, naphthalene group or its derivatives, anthracene group or its derivatives, carbazole group or its derivatives, phenylamino group or its derivatives, acridine group or its derivatives, phenoxazine group or its derivatives, phenothiazine group or its derivatives, and oxazine group or its derivatives.

[0012] Further preferably, the structure of the boron nitrogen heterocyclic derivative is selected from one of the following structural formulas, wherein the general formula A-1 includes a-1 to a-20, the general formula A-2 includes a-21 to a-40, the general formula B-1 includes b-1 to b-16, and the general formula B-2 includes b-17 to b-84:

[0013]

[0014]

[0015]

[0016]

[0017]

[0018]

[0019] According to another aspect of the present invention, the present invention provides a method for preparing the compound represented by general formula A-1, and the preparation process is as follows:

[0020]

[0021] The preparation steps are as follows:

[0022] (1) Add the above-mentioned compound 1, compound 2, benzyl acetone dipalladium (Pd2(dba)3), tri-tert-butylphosphine tetrafluoroborate (t-Bu3PHBF4), sodium tert-butoxide (tBuONa), and dry toluene into a container, heat to 110-130° C. in a nitrogen environment, reflux and stir to react for 8-20 hours, and after the reaction is complete, cool to room temperature, then extract and collect the organic layer using dichloromethane and water, dry and concentrate, and perform preliminary purification by column chromatography. The crude product is further recrystallized using dichloromethane and methanol to obtain compound 3;

[0023] The molar ratio of compound 1, compound 2, benzyl acetone dipalladium, tri-tert-butylphosphine tetrafluoroborate, and sodium tert-butoxide is (45-47): (49-51): (0.9-1): (1.7-1.9): (130-140); the mass volume ratio of compound 1 and toluene is 1 g: (9-11) mL;

[0024] (2) Add the above compound 4, compound 5, benzyl acetone dipalladium, tri-tert-butylphosphine tetrafluoroborate, sodium tert-butoxide, and dry toluene into a container, heat to 110-130° C. in a nitrogen environment, reflux with stirring and react for 8-20 hours, and after the reaction is complete, cool to room temperature, then extract and collect the organic layer with dichloromethane and water, dry and concentrate, perform preliminary purification by column chromatography, and further recrystallize the crude product with dichloromethane and methanol to obtain compound 6; (the reaction ratio of step 2 is the same as that of step (1), only compound 1 and compound 2 need to be replaced by compound 4 and compound 5 respectively)

[0025] (3) Add the above compound 3, compound 6, benzyl acetone dipalladium, tri-tert-butylphosphine tetrafluoroborate, sodium tert-butoxide, and dry toluene into a container, heat to 85-95° C. in a nitrogen environment, reflux with stirring and react for 8-20 hours, and after the reaction is complete, cool to room temperature, then extract and collect the organic layer with dichloromethane and water, dry and concentrate, and perform preliminary purification by column chromatography. The crude product is further recrystallized with dichloromethane and methanol to obtain compound 7; wherein the amount of benzyl acetone dipalladium is 3-6% of the amount of compound 6; the molar ratio of compound 6, tri-tert-butylphosphine tetrafluoroborate, and sodium tert-butoxide is (45-47):(1.7-1.9):(130-140);

[0026] (4) Compound 7 is dried in vacuo in advance and dissolved in o-dichlorobenzene. The air is evacuated, and then boron tribromide is added dropwise in a nitrogen environment. The mixture is heated to 170-190°C and refluxed with stirring for 20-30 hours. After the reaction is complete, the mixture is cooled to -5 to 5°C (preferably 0°C), and N,N-diisopropylethylamine (DIPEA) is added. The mixture is then stirred at -5 to 5°C for 1-3 hours. After the reaction is complete, o-dichlorobenzene is removed by distillation under reduced pressure, and the concentrated mother liquor is collected and initially purified by column chromatography (the eluent is cyclohexane). The crude product is further recrystallized using toluene and methanol to obtain a light yellow solid powder, which is the compound represented by the general formula A-1.

[0027] The ratio of compound 7, boron tribromide, and N,N-diisopropylethylamine is 10g:(3-4.5)mL:(48-55)mL.

[0028] The preparation steps of the compound represented by general formula A-2 differ from those of A-1 in that the changes in reaction temperature and catalyst equivalent in step (3) will produce different compounds 7. The reaction temperature is changed to 105-115°C, and the catalyst equivalent is 18-22% of the amount of compound 6.

[0029] The preparation steps of the compound represented by general formula B-1 are different from those of A-1 in that a heavy atom group X (O, S, Se, Te) is introduced into compound 5:

[0030] The preparation steps of the compound represented by general formula B-2 are different from those of A-2 in that a heavy atom group X (O, S, Se, Te) is introduced into compound 5.

[0031] According to another aspect of the present invention, the present invention provides the use of the boron nitrogen heterocyclic compound based on heavy atom fusion donor in an organic electroluminescent device.

[0032] As a further preferred embodiment of the present invention, the six-membered and seven-membered boron nitrogen heterocyclic derivatives based on heavy atom fusion donors are mainly used as guest luminescent materials and sensitizer luminescent materials in organic electroluminescent devices.

[0033] As a further preferred embodiment of the present invention, the organic electroluminescent device comprises, from top to bottom, an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode; the light-emitting layer comprises the six-membered and seven-membered boron nitrogen heterocyclic derivative;

[0034] Preferably, an exciton blocking layer is provided between the hole transport layer and the light-emitting layer, and between the light-emitting layer and the electron transport layer.

[0035] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0036] 1. The six-membered and seven-membered boron nitrogen heterocyclic derivatives based on heavy atom fusion donors provided by the present invention are formed by fusing different types of single donor groups with heavy atom-containing groups to form a new type of fused heavy atom donor with large volume, large steric hindrance and strong rigidity, and introducing it into the resonance core of the MR-TADF luminescent molecule, thereby obtaining six-membered and seven-membered boron nitrogen heterocyclic derivatives based on heavy atom fusion donors. The present invention can greatly improve the reverse intersystem crossing rate of the material based on the heavy atom effect, and the unique fusion donor effect has a finely adjustable electron supply ability, which can achieve a wide range of control of the emission wavelength and narrowing of the half-peak width of the heavy atom material. Such organic light-emitting molecules are used as light-emitting materials or sensitizer light-emitting materials in the light-emitting layer structure of organic light-emitting diode (OLED) devices, which can achieve controllable adjustment of the wavelength range of 450nm-490nm, and obtain deep blue light and blue-green light OLED devices with higher device efficiency and color purity.

[0037] 2. The present invention prefers hexa- and heptad fused donor-type boron-nitrogen heterocyclic MR-TADF emitters, which break the initial triangular ene structure and further expand the existing blue light boron-nitrogen MR-TADF system. It has obvious advantages in maintaining blue light emission. At the same time, based on the different electron donation capabilities and different numbers of heavy atoms possessed by the fused donors, a wide range of control over the emission wavelength can be achieved. The control range covers the blue light field, greatly enriching the diversity of molecular design strategies. This will be conducive to the further development of blue light materials and has great scientific and technological value and commercial application prospects.

[0038] 3. The hexa- and heptad boron nitrogen heterocyclic derivatives based on heavy atom fusion donors described in the present invention have heavy atoms incorporated into the donors instead of being directly melted into the parent nucleus, which is beneficial to reduce the vibrational relaxation of the molecules and ensure the narrow emission of the heavy atom MR-TADF. The half-width is generally below 50nm, and it is a very rare narrow half-width heavy atom MR-TADF blue light material.

[0039] 4. In addition, heavy atoms such as O, S, Se, Te are introduced into the MR framework to enhance the spin-orbit coupling (SOC) between T1 and S1, increase the reverse intersystem crossing rate of triplet excitons, and reduce the annihilation process related to triplet excitons. Therefore, the heavy atom effect in hexa- and heptad boron nitrogen heterocyclic derivatives is gradually improved, and they are used as luminescent objects in OLED devices, which will be beneficial to improve the efficiency and stability of the devices.

[0040] 5. The introduction of heavy atoms enhances SOC. In the device structure, this will be beneficial as a sensitizer for blue light OLED luminescent materials, enabling efficient Energy transfer can make full use of triplet excitons, so it has an advantage in the development of new MR-TADF sensitizer materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a schematic structural diagram of an electroluminescent device;

[0042] Figure 2 Thermogravimetric analysis curves of Synthesis Examples a-1, a-41, b-33, and b-45;

[0043] Figure 3 are the brightness-external quantum efficiency curves of device embodiments 1, 2, 19, and 20;

[0044] Figure 4 It is the general structural formula of the six-membered and seven-membered boron nitrogen heterocyclic derivative based on the heavy atom fusion donor of the present invention. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0046] The following are examples:

[0047] Synthesis Example 1: The above compound a-1 of the present invention conforms to the general formula A-1 and can be synthesized by the following method:

[0048]

[0049] (1) 1-Chloro-10H-phenoxazine (10 g, 45.94 mmol), aniline (4.66 g, 50.00 mmol), benzyl acetone dipalladium (0.85 g, 0.919 mmol), tri-tert-butylphosphine tetrafluoroborate (0.54 g, 1.838 mmol), sodium tert-butoxide (13.24 g, 137.82 mmol), and dry toluene (100 ml) were added to a 500 ml three-necked flask, and then the mixture was bubbled with nitrogen for 15 minutes, and then heated to 120°C in a nitrogen environment and refluxed for 12 hours. After the reaction was complete, it was cooled to room temperature, and the organic layer was collected by extraction with dichloromethane and water, dried and concentrated, and initially purified by column chromatography. The crude product was further recrystallized with dichloromethane and methanol to obtain a white solid powder, 9.18 g, with a yield of 90.99%.

[0050] (2) The same as step (1), except that the reaction raw materials are changed to m-bromochlorobenzene (10 g, 52.23 mmol) and diphenylamine (9.31 g, 55 mmol), the catalyst, ligand and base are added in the proportions in (1) (the molar ratio relative to m-bromochlorobenzene is the same as the molar ratio relative to 1-chloro-10H-phenoxazine in step 1), and preliminary purification is carried out by column chromatography. The crude product is further recrystallized using dichloromethane and methanol to obtain a white solid powder, 11.82 g, with a yield of 82.64%.

[0051] (3) As in step (1), the product of (1) (9 g, 32.80 mmol), the product of (2) (7.30 g, 32 mmol), the catalyst benzyl acetone dipalladium (1.6 mmol), the ligand tri-tert-butylphosphine tetrafluoroborate (1.28 mmol), and the base sodium tert-butoxide (96 mmol) were added into a flask, the reflux temperature was 90°C, and the product was preliminarily purified by column chromatography and recrystallized to obtain 14.17 g of a white solid powder compound with a yield of 83.49%.

[0052] (4) The white solid powder compound (10 g, 19.32 mmol) was vacuum dried in advance and then dissolved in 200 ml of o-dichlorobenzene. Ultrasonication was used to completely dissolve it. The air was repeatedly pumped out by an oil pump. Then, 3.72 ml of boron tribromide was slowly added dropwise below 25°C in a nitrogen environment. The mixture was heated to 180°C and refluxed with stirring for 24 hours. After the reaction was complete, the mixture was cooled to 0°C and 50.47 ml of N,N-diisopropylethylamine (DIPEA) was added. The mixture was stirred at 0°C for 2 hours. After the reaction was complete, the o-dichlorobenzene was removed by vacuum distillation. The concentrated mother liquor was collected and initially purified by column chromatography (the eluent was cyclohexane). The crude product was further recrystallized with toluene and methanol to obtain 4.21 g of light yellow solid powder with a yield of 41.52%.

[0053] High resolution mass spectrometer APCI-MS (m / z): Theoretical molecular weight is 525.42, test value: 525.37. Elemental analysis results: Theoretical value: C: 82.30%; H: 4.60%; B: 2.06%; N: 8.00%; O: 3.05. Experimental value: C: 82.35%; H: 4.61%; B: 2.01%; N: 8.01%; O: 3.03. NMR 1 H NMR(500MHz,Chloroform-d)δ7.44-7.30(m,4H),7.34-7.23(m,1H),7.18(td,J=7.9,1 .5Hz,1H),7.14-6.96(m,5H),6.86(d,J=7.0Hz,1H),6.71(ddd,J=8.4,4.0,1.3Hz,1H).

[0054] Synthesis Example 2: The above compound a-21 of the present invention conforms to the general formula A-2 and can be synthesized by the following method:

[0055]

[0056] This embodiment is basically the same as the first three steps of Synthesis Example 1, except that the changes in reaction temperature (reflux temperature is adjusted to 110°C) and catalyst equivalent (6.4 mmol) in step (3) have different effects on the generation tendency of the two products in the third step of Examples 1 and 2.

[0057] High resolution mass spectrometer APCI-MS (m / z): Theoretical molecular weight is 525.42, test value: 525.37. Elemental analysis results: Theoretical value: C: 82.30%; H: 4.60%; B: 2.06%; N: 8.00%; O: 3.05. Experimental value: C: 82.35%; H: 4.61%; B: 2.01%; N: 8.01%; O: 3.03. NMR 1H NMR (500MHz, Chloroform-d) δ7.45 (dd, J = 8.0, 1.4 Hz, 1H), 7.37-7.22 (m, 6H), 7.22-7.05 (m, 10H), 7.05-6.97 (m, 1H), 6.88 (ddd, J = 7.5, 2.3, 1.2 Hz, 3H), 6.83 (dd, J = 7.1, 1.1 Hz, 1H), 6.75 (dd, J = 8.4, 1.1 Hz, 1H). The results of mass spectrum, elemental analysis and hydrogen spectrum show that the product has a correct structure and is the target compound a-21.

[0058] Synthesis Example 3: The above compound a-33 of the present invention conforms to the general formula A-2 and can be synthesized by the following method:

[0059]

[0060] This embodiment is basically the same as Synthesis Example 2, except that diphenylamine needs to be replaced with an equal amount of bis(4-(tert-butyl)phenyl)amine in this embodiment, and the other conditions remain unchanged. High-resolution mass spectrometer APCI-MS (m / z): theoretical molecular weight is 637.63, test value: 637.57. Elemental analysis results: theoretical value: C: 82.88%; H: 6.32%; B: 1.70%; N: 6.59%; O: 2.51. Experimental value: C: 82.85%; H: 6.34%; B: 1.71%; N: 6.57%; O: 2.49. Nuclear magnetic resonance 1 H NMR (500MHz, Chloroform-d) δ7.35-7.26 (m, 6H), 7.26-7.13 (m, 5H), 7.13-7.06 (m, 3H), 7.06-6.93 (m, 4H), 6.91-6.81 (m, 4H), 1.34 (d, J = 0.7 Hz, 18H). The results of mass spectrometry, elemental analysis and hydrogen spectrum show that the product has a correct structure and is the target compound a-33.

[0061] Synthesis Example 4: The above compound b-1 of the present invention conforms to the general formula B-1 and can be synthesized by the following method:

[0062]

[0063] This example is basically the same as Synthesis Example 1, except that diphenylamine needs to be replaced with an equal amount of phenoxazine in this example, and the other conditions remain unchanged. Finally, 4.46 g of yellow solid was obtained. High-resolution mass spectrometer APCI-MS (m / z): 539.38, theoretical molecular weight is 539.40. Elemental analysis results: theoretical value: C: 80.16%; H: 4.11%; B: 2.00%; N: 7.79%; O: 5.93. Experimental value: C: 80.18%; H: 4.13%; B: 2.00%; N: 7.77%; O: 5.91%. Nuclear magnetic resonance 1 H NMR (500MHz, Chloroform-d) δ7.50 (dd, J = 7.1, 1.5Hz, 1H), 7.44-7.34 (m, 4H), 7.37-7.30 (m, 2H), 7.25-7.18 (m, 3H), 7.20-7.14 (m, 1H), 7.14-7.07 (m, 3H), 7.02-6.94 (m, 3H), 6.94 (dd, J = 7.0, 1.2Hz, 1H), 6.84 (ddd, J = 18.7, 7.0, 1.5Hz, 2H), 6.71 (ddd, J = 8.4, 4.0, 1.3Hz, 2H). The results of mass spectrum, elemental analysis and hydrogen spectrum show that the product has a correct structure and is the target compound b-1.

[0064] Synthesis Example 5: The above compound b-17 of the present invention conforms to the general formula B-2 and can be synthesized by the following method:

[0065]

[0066] This example is basically the same as Synthesis Example 2, except that: in this example, diphenylamine needs to be replaced with an equal amount of phenoxazine, and the other conditions remain unchanged. Finally, 4.62 g of yellow solid was obtained. High-resolution mass spectrometer APCI-MS (m / z): 539.38, theoretical molecular weight is 539.40. Elemental analysis results: theoretical value: C: 80.16%; H: 4.11%; B: 2.00%; N: 7.79%; O: 5.93. Experimental value: C: 80.18%; H: 4.13%; B: 2.00%; N: 7.77%; O: 5.91%. Nuclear magnetic resonance 1H NMR (500MHz, Chloroform-d) δ7.41 (dd, J = 7.1, 1.5Hz, 1H), 7.33-7.22 (m, 5H), 7.22-7.06 (m, 8H), 7.01 (tt, J = 7.4, 1.5Hz, 1H), 6.91-6.88 (m, 3H), 6.88-6.82 (m, 2H), 6.77-6.69 (m, 2H). The results of mass spectrometry, elemental analysis and hydrogen spectrum show that the product has a correct structure and is the target compound b-17.

[0067] Synthesis Example 6: The above compound b-25 of the present invention conforms to the general formula B-2 and can be synthesized by the following method:

[0068]

[0069] This example is basically the same as Synthesis Example 3, except that: in this example, phenoxazine needs to be replaced with an equal amount of pheneselenazine, and the other conditions remain unchanged. Finally, 3.28 g of yellow solid was obtained with a yield of 32.43%. High-resolution mass spectrometer APCI-MS (m / z): 602.45, theoretical molecular weight is 602.37. Elemental analysis results: theoretical value: C: 71.78%; H: 3.68%; B: 1.79%; N: 6.98%; O: 2.66; Se: 13.11. Experimental value: C: 71.75%; H: 3.66%; B: 1.78%; N: 6.96%; O: 2.67%; Se: 13.12. Nuclear magnetic resonance 1 H NMR (500 MHz, Chloroform-d) δ7.82-7.73 (m, 2H), 7.44 (dd, J = 7.3, 1.1 Hz, 1H), 7.39-7.34 (m, 2H), 7.31 (t, J = 7.1 Hz, 1H), 7.27-7.22 (m, 2H), 7.22-7.06 (m, 7H), 7.05-6.97 (m, 2H), 6.89-6.86 (m, 3H), 6.86-6.82 (m, 1H), 6.72 (dd, J = 8.4, 1.3 Hz, 1H). The results of mass spectrometry, elemental analysis and hydrogen spectrum show that the product has a correct structure and is the target compound b-25.

[0070] Synthesis Example 7: The above compound b-65 of the present invention conforms to the general formula B-2 and can be synthesized by the following method:

[0071]

[0072] (1) Same as step (1) of Synthesis Example 2;

[0073] (2) 1,3-Dibromo-5-chlorobenzene (10 g, 36.99 mmol), phenoselenazine (9.85 g, 40 mmol), tridibenzylideneacetone dipalladium (0.68 g, 0.74 mmol), DPEphos (0.43 g, 1.48 mmol), sodium tert-butoxide (10.65 g, 111 mmol), and dry toluene (200 ml) were added to a 500 ml three-necked flask, and then the mixture was bubbled with nitrogen for 15 minutes, and then heated to 120°C in a nitrogen environment and refluxed for 12 hours. After the reaction was complete, it was cooled to room temperature, and the organic layer was collected by dichloromethane and water extraction, dried and concentrated, and initially purified by column chromatography. The crude product was further recrystallized with dichloromethane and methanol to obtain a white solid powder, 12.14 g, with a yield of 75.36%.

[0074] (3) The same as step (2), except that the reactants were replaced with the product of (1) (9 g, 32.80 mmol) and the product of (2) (13.94 g, 32 mmol), and the catalyst, ligand, and base were added in the proportions of step (2). The mixture was initially purified by column chromatography and recrystallized to obtain 14.08 g of a white solid powder compound with a yield of 69.98%.

[0075] (4) The same as step (3), except that the reactants were replaced with the product of (3) (10 g, 15.89 mmol) and diphenylamine (2.71 g, 16 mmol), and the catalyst, ligand, and base were added in the proportions of step (2). The mixture was initially purified by column chromatography and recrystallized to obtain 11.55 g of a white solid powder compound with a yield of 95.42%.

[0076] (5) The same as step (4) of Example 2, except that the compound of step (4) of Example 2 was replaced by the product of step (4) of this example (10 g, 36.45 mmol), and the other conditions remained unchanged. Finally, 4.01 g of yellow solid was obtained, with a yield of 39.72%.

[0077] High resolution mass spectrometer APCI-MS (m / z): 769.58, theoretical molecular weight 769.49. Elemental analysis results: Theoretical value: C: 74.91%; H: 4.06%; B: 1.40%; N: 7.28%; O: 2.08%; Se: 10.26%. Experimental value: C: 74.90%; H: 4.08%; B: 1.37%; N: 7.26%; O: 2.09%; Se: 10.29%. Nuclear magnetic resonance 1H NMR (500MHz, Chloroform-d) δ7.82-7.73 (m, 2H), 7.44 (dd, J = 7.3, 1.1Hz, 1H), 7.39-7.32 (m, 2H), 7.32-7.22 (m, 6H), 7.22-7.18 (m, 2H), 7.18-7.07 (m, 10H), 7.07-6.97 (m, 4H), 6.86 (ddd, J = 13.6, 7.5, 1.0Hz, 2H), 6.72 (dd, J = 8.4, 1.3Hz, 1H), 6.68-6.62 (m, 2H). The results of mass spectrum and elemental analysis show that the product has a correct structure and is the target compound b-65.

[0078] These six-membered and seven-membered boron nitrogen heterocyclic derivatives based on heavy atom fusion donors can be used as guest luminescent materials and sensitizers in devices. The device preparation process can be as follows: ITO (indium tin oxide) glass substrate is ultrasonically cleaned in ITO cleaning agent, isopropyl alcohol, acetone, ethanol, and deionized water for 60 minutes. After drying with dry nitrogen, it is dried in an oven at 120°C for 2 hours. Before preparing the device, the ITO glass substrate was treated with oxygen plasma for 10 minutes, and then transferred to an organic vacuum chamber to evaporate the organic functional layer material. A 10nm thick hole injection material HAT-CN (2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene) was prepared by vacuum evaporation, followed by evaporation of a 50nm thick hole transport material TAPC (4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline]), and then a 10nm thick electron blocking layer mCBP (3,3-di(carbazolyl)biphenyl) was vacuum evaporated on the hole transport layer, and then a 20nm thick light-emitting layer was evaporated, and then a 40nm thick electron transport material TmPyPB (1,3,5-tris(3-pyridyl-3-phenyl)benzene) was evaporated in sequence, and finally a 1nm thick LiF and 10nm Al layer were evaporated. The schematic diagram of the device structure is shown in the figure. Figure 1 As shown, in practical applications, the exciton blocking layer structure can be selectively used or not according to the energy gap (luminescent color) of the hexa- and heptadiene-borane heterocyclic derivatives based on the heavy atom fusion donor in the present invention; in addition, the transport layer material system can be screened according to the energy level matching principle and the electron-hole carrier balance principle, and the film thickness, the luminescent layer thickness and the host-guest doping concentration can be optimized.

[0079] The device structure of the embodiment of the present invention is specifically as follows:

[0080] (1) When the six-membered and seven-membered boron nitrogen heterocyclic derivatives of the heavy atom fusion donor are used as the guest luminescent material (Dopant), the device structure is:

[0081] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:Dopant(20nm,3wt%) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0082] (2) When the fusion donor hexa- and heptad-borane heterocyclic derivatives are used as sensitizer materials, the device structure is:

[0083] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:20wt%Sensitizer:x wt%PhDMAC-BN(x=3) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0084] The following is a device embodiment (each organic functional layer is optimized):

[0085] Device Comparison Example 1:

[0086] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:Dopant(20nm,3wt%) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0087] The guest luminescent material (Dopant) of the luminescent layer is a conventional MR-TADF monoboron compound PhDMAC-BN. The device has an electroluminescent peak wavelength of 480nm, a half-peak width (FWHM) of 34nm, and a maximum external quantum efficiency (EQE max ) is 21.6%, the driving voltage is 3.4V, and the device life LT 95 77 hours @ initial brightness 2000cd / m 2 .

[0088] Device Example 1:

[0089] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:Dopant(20nm,3wt%) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0090] The guest luminescent material (Dopant) of the luminescent layer is the fused donor compound a-1 described in the present invention. The device has an electroluminescent peak wavelength of 471 nm, a half-peak width (FWHM) of 27 nm, and a maximum external quantum efficiency (EQE max ) is 29.7%, the driving voltage is 3.4V, and the device life LT 9591 hours @ initial brightness 2000cd / m 2 .

[0091] Device Example 2:

[0092] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:Dopant(20nm,3wt%) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0093] The guest luminescent material (Dopant) of the luminescent layer is the fused donor compound a-5 described in the present invention. The peak wavelength of electroluminescence of the device is 468nm, the half-peak width (FWHM) is 24nm, and the maximum external quantum efficiency (EQE max ) is 30.5%, the driving voltage is 3.4V, and the device life LT 95 94 hours @ initial brightness 2000cd / m 2 .

[0094] Device Example 3:

[0095] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:Dopant(20nm,3wt%) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0096] The guest luminescent material (Dopant) of the luminescent layer is the fused donor compound a-17 described in the present invention. The electroluminescent peak wavelength of the device is 471nm, the half-peak width (FWHM) is 27nm, and the maximum external quantum efficiency (EQE max ) is 31.4%, the driving voltage is 3.5V, and the device life LT 95 91 hours @ initial brightness 2000cd / m 2 .

[0097] Device Example 4:

[0098] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:Dopant(20nm,3wt%) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0099] The guest luminescent material (Dopant) of the luminescent layer is the fused donor compound a-25 described in the present invention. The electroluminescent peak wavelength of the device is 469nm, the half-peak width (FWHM) is 27nm, and the maximum external quantum efficiency (EQE max) is 31.2%, the driving voltage is 3.5V, and the device life LT 95 105 hours @ initial brightness 2000cd / m 2 .

[0100] Device Example 5:

[0101] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:Dopant(20nm,3wt%) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0102] The guest luminescent material (Dopant) of the luminescent layer is the fused donor compound a-33 described in the present invention. The device has an electroluminescent peak wavelength of 473 nm, a half-peak width (FWHM) of 26 nm, and a maximum external quantum efficiency (EQE max ) is 32.9%, the driving voltage is 3.4V, and the device life LT 95 96 hours @ initial brightness 2000cd / m 2 .

[0103] Device Example 6:

[0104] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:Dopant(20nm,3wt%) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0105] The guest luminescent material (Dopant) of the luminescent layer is the fused donor compound a-40 described in the present invention. The peak wavelength of electroluminescence of the device is 476nm, the half-peak width (FWHM) is 30nm, and the maximum external quantum efficiency (EQE max ) is 32.1%, the driving voltage is 3.4V, and the device life LT 95 100 hours @ initial brightness 2000cd / m 2 .

[0106] Device Example 7:

[0107] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:Dopant(20nm,3wt%) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0108] The guest luminescent material (Dopant) of the luminescent layer is the fused donor compound b-5 described in the present invention. The peak wavelength of electroluminescence of the device is 497nm, the half-peak width (FWHM) is 35nm, and the maximum external quantum efficiency (EQE max ) is 31.5%, the driving voltage is 3.4V, and the device life LT 95 85 hours @ initial brightness 4000cd / m 2 .

[0109] Device Example 8:

[0110] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:Dopant(20nm,3wt%) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0111] The guest luminescent material (Dopant) of the luminescent layer is the fused donor compound b-30 described in the present invention. The electroluminescent peak wavelength of the device is 485nm, the half-peak width (FWHM) is 32nm, and the maximum external quantum efficiency (EQE max ) is 33.5%, the driving voltage is 3.4V, and the device life LT 95 91 hours @ initial brightness 2000cd / m 2 .

[0112] Device Example 9:

[0113] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:Dopant(20nm,3wt%) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0114] The guest luminescent material (Dopant) of the luminescent layer is the fused donor compound b-37 described in the present invention. The peak wavelength of electroluminescence of the device is 465nm, the half-peak width (FWHM) is 25nm, and the maximum external quantum efficiency (EQE max ) is 33.8%, the driving voltage is 3.3V, and the device life LT 95 89 hours @ initial brightness 2000cd / m 2 .

[0115] Device Example 10:

[0116] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:Dopant(20nm,3wt%) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0117] The guest luminescent material (Dopant) of the luminescent layer is the fused donor compound b-39 described in the present invention. The device has an electroluminescent peak wavelength of 470nm, a half-peak width (FWHM) of 27nm, a maximum external quantum efficiency (EQEmax) of 34.8%, a driving voltage of 3.5V, and a device life of LT 95 92 hours @ initial brightness 2000cd / m 2 .

[0118] Device Example 11:

[0119] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:20wt%Sensitizer:x wt%PhDMAC-BN(x=3) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0120] The sensitizer material of the light-emitting layer is the fusion donor compound a-1 described in the present invention, and the luminescent object is PhDMAC-BN. The electroluminescent peak wavelength of the device is 480nm, the half-peak width (FWHM) is 34nm, and the maximum external quantum efficiency (EQE max ) is 30.9%, the driving voltage is 3.4V, and the device life LT 95 91 hours @ initial brightness 6000cd / m 2 .

[0121] Device Example 12:

[0122] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:20wt%Sensitizer:x wt%PhDMAC-BN(x=3) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0123] The sensitizer material of the light-emitting layer is the fusion donor compound a-5 described in the present invention, and the luminescent object is PhDMAC-BN. The electroluminescence peak wavelength of the device is 480nm, the half-peak width (FWHM) is 34nm, and the maximum external quantum efficiency (EQE max ) is 31.2%, the driving voltage is 3.4V, and the device life LT 95 92 hours @ initial brightness 6000cd / m 2 .

[0124] Device Example 13:

[0125] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:20wt%Sensitizer:x wt%PhDMAC-BN(x=3) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0126] The sensitizer material of the light-emitting layer is the fusion donor compound a-17 described in the present invention, and the luminescent object is PhDMAC-BN. The electroluminescent peak wavelength of the device is 480nm, the half-peak width (FWHM) is 34nm, and the maximum external quantum efficiency (EQE max ) is 31.8%, the driving voltage is 3.4V, and the device life LT 95 94 hours @ initial brightness 6000cd / m 2 .

[0127] Device Example 14:

[0128] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:20wt%Sensitizer:x wt%PhDMAC-BN(x=3) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0129] The sensitizer material of the light-emitting layer is the fusion donor compound a-25 described in the present invention, and the luminescent object is PhDMAC-BN. The electroluminescent peak wavelength of the device is 480nm, the half-peak width (FWHM) is 34nm, and the maximum external quantum efficiency (EQE max ) is 32.4%, the driving voltage is 3.4V, and the device life LT 95 100 hours @ initial brightness 6000cd / m 2 .

[0130] Device Example 15:

[0131] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:20wt%Sensitizer:x wt%PhDMAC-BN(x=3) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0132] The sensitizer material of the light-emitting layer is the fusion donor compound a-33 described in the present invention, and the luminescent object is PhDMAC-BN. The electroluminescent peak wavelength of the device is 480nm, the half-peak width (FWHM) is 34nm, and the maximum external quantum efficiency (EQE max) is 32.6%, the driving voltage is 3.4V, and the device life LT 95 99 hours @ initial brightness 6000cd / m 2 .

[0133] Device Example 16:

[0134] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:20wt%Sensitizer:x wt%PhDMAC-BN(x=3) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0135] The sensitizer material of the light-emitting layer is the fused donor compound b-1 described in the present invention. The peak wavelength of electroluminescence of the device is 480nm, the half-peak width (FWHM) is 34nm, the maximum external quantum efficiency (EQEmax) is 32.4%, the driving voltage is 3.4V, and the device life LT 95 103 hours @ initial brightness 6000cd / m 2 .

[0136] Device Example 17:

[0137] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:20wt%Sensitizer:x wt%PhDMAC-BN(x=3) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0138] The sensitizer material of the light-emitting layer is the fused donor compound b-33 described in the present invention. The peak wavelength of electroluminescence of the device is 480nm, the half-peak width (FWHM) is 34nm, the maximum external quantum efficiency (EQEmax) is 32.6%, the driving voltage is 3.4V, and the device life LT 95 89 hours @ initial brightness 6000cd / m 2 .

[0139] Device Example 18:

[0140] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:20wt%Sensitizer:x wt%PhDMAC-BN(x=3) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0141] The sensitizer material of the light-emitting layer is the fused donor compound b-34 described in the present invention. The peak wavelength of electroluminescence of the device is 480nm, the half-peak width (FWHM) is 34nm, the maximum external quantum efficiency (EQEmax) is 34.1%, the driving voltage is 3.4V, and the device life LT 95 96 hours @ initial brightness 6000cd / m 2 .

[0142] Device Example 19:

[0143] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:20wt%Sensitizer:x wt%PhDMAC-BN(x=3) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0144] The sensitizer material of the light-emitting layer is the fusion donor compound b-36 described in the present invention. The peak wavelength of electroluminescence of the device is 480nm, the half-peak width (FWHM) is 34nm, the maximum external quantum efficiency (EQEmax) is 33.8%, the driving voltage is 3.4V, and the device life LT 95 90 hours @ initial brightness 6000cd / m 2 .

[0145] Device Example 20:

[0146] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:20wt%Sensitizer:x wt%PhDMAC-BN(x=3) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0147] The guest luminescent material (Dopant) of the luminescent layer is the fusion donor compound b-38 described in the present invention. The device has an electroluminescent peak wavelength of 480nm, a half-peak width (FWHM) of 34nm, a maximum external quantum efficiency (EQEmax) of 34.8%, a driving voltage of 3.4V, and a device life of LT 95 94 hours @ initial brightness 6000cd / m 2 .

[0148] Device Example 21:

[0149] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:20wt%Sensitizer:x wt%Dopant(x=3) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0150] The sensitizer material of the light-emitting layer is the fused donor compound b-49 described in the present invention, and the guest luminescent material of the light-emitting layer is the fused donor compound a-1 described in the present invention. The electroluminescent peak wavelength of the device is 471nm, the half-peak width (FWHM) is 27nm, and the maximum external quantum efficiency (EQE max ) is 30.5%, the driving voltage is 3.4V, and the device life LT 95 103 hours @ initial brightness 8000cd / m 2 .

[0151] Device Example 22:

[0152] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:20wt%Sensitizer:x wt%Dopant(x=3) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0153] The sensitizer material of the light-emitting layer is the fused donor compound b-49 described in the present invention, and the guest luminescent material of the light-emitting layer is the fused donor compound a-41 described in the present invention. The electroluminescent peak wavelength of the device is 476nm, the half-peak width (FWHM) is 30nm, and the maximum external quantum efficiency (EQE max ) is 34.2%, the driving voltage is 3.4V, and the device life LT 95 100 hours @ initial brightness 8000cd / m 2 .

[0154] Device Example 23:

[0155] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:20wt%Sensitizer:x wt%Dopant(x=3) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0156] The sensitizer material of the light-emitting layer is the fused donor compound b-49 described in the present invention, and the guest luminescent material of the light-emitting layer is the fused donor compound b-5 described in the present invention. The electroluminescent peak wavelength of the device is 497nm, the half-peak width (FWHM) is 35nm, and the maximum external quantum efficiency (EQE max ) is 33.9%, the driving voltage is 3.4V, and the device life LT 95 85 hours @ initial brightness 8000cd / m 2 .

[0157] Device Example 24:

[0158] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:20wt%Sensitizer:x wt%Dopant(x=3) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0159] The sensitizer material of the light-emitting layer is the fused donor compound b-49 described in the present invention, and the guest luminescent material of the light-emitting layer is the fused donor compound b-30 described in the present invention. The electroluminescent peak wavelength of the device is 485nm, the half-peak width (FWHM) is 32nm, and the maximum external quantum efficiency (EQE max ) is 35.5%, the driving voltage is 3.4V, and the device life LT 95 91 hours @ initial brightness 8000cd / m 2 .

[0160] Device Example 25:

[0161] ITO / HAT-CN(10nm) / TAPC(50nm) / mCBP(10nm) / mCBP:20wt%Sensitizer:x wt%Dopant(x=3) / TmPyPB(40nm) / LiF(1nm) / Al(100nm)

[0162] The sensitizer material of the light-emitting layer is the fused donor compound b-49 described in the present invention, and the guest luminescent material of the light-emitting layer is the fused donor compound b-39 described in the present invention. The electroluminescent peak wavelength of the device is 470nm, the half-peak width (FWHM) is 27nm, and the maximum external quantum efficiency (EQE max ) is 36.8%, the driving voltage is 3.5V, and the device life LT 95 92 hours @ initial brightness 8000cd / m 2 .

[0163] In the above examples, it has been verified that the compounds of the present invention achieve spectral regulation within a relatively large wavelength range and maintain a narrow luminescence half-peak width. Figure 2 The thermogravimetric curves of some molecules show that the six-membered and seven-membered boron nitrogen heterocyclic derivatives of heavy atom fusion donors have excellent thermal stability and meet the needs of the industry. The compounds of the present invention are applied to OLED devices to obtain excellent device performance. Figure 3 This is a brightness-external quantum efficiency curve of a device embodiment. Therefore, it can be clearly determined that the compound of the present invention has excellent electroluminescent properties and has great industrial application potential.

[0164] In summary, the present invention aims at the problems of single MR-TADF material system, less heavy atom narrow emission blue light materials and low utilization rate of triplet excitons, and provides a six-membered and seven-membered boron nitrogen heterocyclic derivative based on heavy atom fusion donor. By fusing different types of single donor groups with heavy atom-containing groups, a new type of fused heavy atom donor with large volume, large steric hindrance and strong rigidity is formed, and the new type of fused heavy atom donor is introduced into the resonance core of the MR-TADF luminescent molecule. Such organic luminescent molecules are used as luminescent materials or sensitizer luminescent materials in the light-emitting layer structure of organic light-emitting diode (OLED) devices, so as to achieve controllable adjustment in the wavelength range of 450nm-490nm, and obtain deep blue light and blue-green light OLED devices with higher device efficiency and color purity.

[0165] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A six-membered and seven-membered boron nitrogen heterocyclic derivative based on a heavy atom fusion donor, characterized in that: The six-membered and seven-membered boron nitrogen heterocyclic derivative based on the heavy atom fusion donor has a structure as described in at least one of the general formulas A-1, A-2, B-1, and B-2: Wherein, R1, R2, and R3 are each independently selected from any one of hydrogen, deuterium, methyl, tert-butyl, phenyl, an aromatic amine group having 6 to 24 carbon atoms or its derivatives, an aromatic amine heterocyclic group having 12 to 24 carbon atoms or its derivatives; Ar is selected from any one of hydrogen, deuterium, methyl, monophenyl group, biphenyl group, naphthalene group, anthracene group, carbazole group, phenylamino group, acridine group, phenoxazine group, phenothiazine group, and oxazine group; X represents a heavy atom, and is selected from any one of carbon, oxygen, sulfur, selenium and tellurium atoms.

2. The six-membered and seven-membered boron nitrogen heterocyclic derivative based on a heavy atom fusion donor according to claim 1, characterized in that: R1, R2, and R3 are each independently selected from any one of hydrogen, deuterium, methyl, tert-butyl, diphenylamino, carbazolyl, phenothiazinyl, phenoxazinyl, 9,10-dihydroacridinyl, 9,9-diphenylacridinyl, 9,9-dimethylacridinyl, diphenylamino derivatives, carbazolyl derivatives, 9,10-dihydroacridinyl derivatives, 9,9-diphenylacridinyl derivatives, or 9,9-dimethylacridinyl derivatives.

3. The six-membered and seven-membered boron nitrogen heterocyclic derivative based on a heavy atom fusion donor according to claim 1, characterized in that: Ar is selected from any one of hydrogen, deuterium, methyl, monobenzene group or its derivatives, biphenyl group or its derivatives, naphthalene group or its derivatives, anthracene group or its derivatives, carbazole group or its derivatives, phenylamino group or its derivatives, acridine group or its derivatives, phenoxazine group or its derivatives, phenothiazine group or its derivatives, and oxazine group or its derivatives.

4. The six-membered and seven-membered boron nitrogen heterocyclic derivative based on a heavy atom fusion donor according to claim 1, characterized in that: The structure of the boron nitrogen heterocyclic derivative is one selected from the following structural formulas, wherein the general formula A-1 includes one of a-1 to a-20, the general formula A-2 includes one of a-21 to a-40, the general formula B-1 includes one of b-1 to b-16, and the general formula B-2 includes one of b-17 to b-84:

5. A method for preparing a six-membered and seven-membered boron nitrogen heterocyclic derivative based on a heavy atom fusion donor according to any one of claims 1 to 4, characterized in that: When the six-membered and seven-membered boron nitrogen heterocyclic derivative satisfies the general formula A-1, the preparation process is as follows: The preparation steps are as follows: (1) Add the above-mentioned compound 1, compound 2, benzyl acetone dipalladium, tri-tert-butylphosphine tetrafluoroborate, sodium tert-butoxide, and dry toluene into a container, heat to 110-130° C. in a nitrogen environment, reflux and stir to react, and after the reaction is complete, cool to room temperature, then extract and collect the organic layer, and then purify to obtain compound 3; (2) Add the above compound 4, compound 5, benzyl acetone dipalladium, tri-tert-butylphosphine tetrafluoroborate, sodium tert-butoxide, and dry toluene into a container, heat to 110-130° C. in a nitrogen environment, reflux and stir to react, and after the reaction is complete, cool to room temperature, extract and collect the organic layer, and then purify to obtain compound 6; (3) Add the above compound 3, compound 6, benzyl acetone dipalladium, tri-tert-butylphosphine tetrafluoroborate, sodium tert-butoxide, and dry toluene into a container, heat to 85-95° C. in a nitrogen environment, reflux and stir to react, and after the reaction is complete, cool to room temperature, extract and collect the organic layer, and purify to obtain compound 7; wherein the amount of benzyl acetone dipalladium is 3-6% of the amount of compound 6; (4) Compound 7 is dried in vacuo in advance and then dissolved in o-dichlorobenzene. The air is evacuated, and then boron tribromide is added dropwise in a nitrogen environment. The mixture is heated to 170-190°C and refluxed with stirring for reaction. After the reaction is complete, the mixture is cooled to -5-5°C, N,N-diisopropylethylamine is added, and then the mixture is stirred at -5-5°C for reaction. After the reaction is complete, the o-dichlorobenzene is removed by distillation under reduced pressure, and the concentrated mother liquor is collected and purified to obtain a light yellow solid powder, which is the compound represented by the general formula A-1.

6. A method for preparing a six-membered and seven-membered boron nitrogen heterocyclic derivative based on a heavy atom fusion donor according to any one of claims 1 to 4, characterized in that: When the six-membered and seven-membered boron nitrogen heterocyclic derivative satisfies the general formula A-2, the preparation process is as follows: The preparation steps are as follows: (1) Add the above-mentioned compound 1, compound 2, benzyl acetone dipalladium, tri-tert-butylphosphine tetrafluoroborate, sodium tert-butoxide, and dry toluene into a container, heat to 110-130° C. in a nitrogen environment, reflux and stir to react, and after the reaction is complete, cool to room temperature, then extract and collect the organic layer, and then purify to obtain compound 3; (2) Add the above compound 4, compound 5, benzyl acetone dipalladium, tri-tert-butylphosphine tetrafluoroborate, sodium tert-butoxide, and dry toluene into a container, heat to 110-130° C. in a nitrogen environment, reflux and stir to react, and after the reaction is complete, cool to room temperature, extract and collect the organic layer, and then purify to obtain compound 6; (3) Add the above compound 3, compound 6, benzyl acetone dipalladium, tri-tert-butylphosphine tetrafluoroborate, sodium tert-butoxide, and dry toluene into a container, heat to 105-115° C. in a nitrogen environment, reflux and stir to react, and after the reaction is complete, cool to room temperature, extract and collect the organic layer, and purify to obtain compound 7; wherein the amount of benzyl acetone dipalladium is 18-22% of the amount of compound 6; (4) Compound 7 is dried in vacuo in advance and then dissolved in o-dichlorobenzene. The air is evacuated, and then boron tribromide is added dropwise in a nitrogen environment. The mixture is heated to 170-190°C and refluxed with stirring for reaction. After the reaction is complete, the mixture is cooled to -5-5°C, N,N-diisopropylethylamine is added, and then the mixture is stirred at -5-5°C for reaction. After the reaction is complete, the o-dichlorobenzene is removed by distillation under reduced pressure, and the concentrated mother liquor is collected and purified to obtain a light yellow solid powder, which is the compound represented by the general formula A-2.

7. A method for preparing a six-membered and seven-membered boron nitrogen heterocyclic derivative based on a heavy atom fusion donor according to any one of claims 1 to 4, characterized in that: When the six-membered and seven-membered boron nitrogen heterocyclic derivative satisfies the general formula B-1, the method comprises the following steps: The preparation process is as follows: The preparation steps are as follows: (1) Add the above-mentioned compound 1, compound 2, benzyl acetone dipalladium, tri-tert-butylphosphine tetrafluoroborate, sodium tert-butoxide, and dry toluene into a container, heat to 110-130° C. in a nitrogen environment, reflux and stir to react, and after the reaction is complete, cool to room temperature, then extract and collect the organic layer, and then purify to obtain compound 3; (2) Add the above compound 4, compound 5, benzyl acetone dipalladium, tri-tert-butylphosphine tetrafluoroborate, sodium tert-butoxide, and dry toluene into a container, heat to 110-130° C. in a nitrogen environment, reflux and stir to react, and after the reaction is complete, cool to room temperature, extract and collect the organic layer, and then purify to obtain compound 6; (3) Add the above compound 3, compound 6, benzyl acetone dipalladium, tri-tert-butylphosphine tetrafluoroborate, sodium tert-butoxide, and dry toluene into a container, heat to 85-95° C. in a nitrogen environment, reflux and stir to react, and after the reaction is complete, cool to room temperature, extract and collect the organic layer, and purify to obtain compound 7; wherein the amount of benzyl acetone dipalladium is 3-6% of the amount of compound 6; (4) Compound 7 is dried in vacuo in advance and then dissolved in o-dichlorobenzene. The air is evacuated, and then boron tribromide is added dropwise in a nitrogen environment. The mixture is heated to 170-190°C and refluxed with stirring for reaction. After the reaction is complete, the mixture is cooled to -5-5°C, N,N-diisopropylethylamine is added, and then the mixture is stirred at -5-5°C for reaction. After the reaction is complete, the o-dichlorobenzene is removed by distillation under reduced pressure, and the concentrated mother liquor is collected and purified to obtain a light yellow solid powder, which is the compound represented by the general formula B-1.

8. A method for preparing a six-membered and seven-membered boron nitrogen heterocyclic derivative based on a heavy atom fusion donor according to any one of claims 1 to 4, characterized in that: When the six-membered and seven-membered boron nitrogen heterocyclic derivative satisfies the general formula B-2, the method comprises the following steps: The preparation process is as follows: The preparation steps are as follows: (1) Add the above-mentioned compound 1, compound 2, benzyl acetone dipalladium, tri-tert-butylphosphine tetrafluoroborate, sodium tert-butoxide, and dry toluene into a container, heat to 110-130° C. in a nitrogen environment, reflux and stir to react, and after the reaction is complete, cool to room temperature, then extract and collect the organic layer, and then purify to obtain compound 3; (2) Add the above compound 4, compound 5, benzyl acetone dipalladium, tri-tert-butylphosphine tetrafluoroborate, sodium tert-butoxide, and dry toluene into a container, heat to 110-130° C. in a nitrogen environment, reflux and stir to react, and after the reaction is complete, cool to room temperature, extract and collect the organic layer, and then purify to obtain compound 6; (3) Add the above compound 3, compound 6, benzyl acetone dipalladium, tri-tert-butylphosphine tetrafluoroborate, sodium tert-butoxide, and dry toluene into a container, heat to 105-115° C. in a nitrogen environment, reflux and stir to react, and after the reaction is complete, cool to room temperature, extract and collect the organic layer, and purify to obtain compound 7; wherein the amount of benzyl acetone dipalladium is 18-22% of the amount of compound 6; (4) Compound 7 is dried in vacuo in advance and then dissolved in o-dichlorobenzene. The air is evacuated, and then boron tribromide is added dropwise in a nitrogen environment. The mixture is heated to 170-190°C and refluxed with stirring for reaction. After the reaction is complete, the mixture is cooled to -5-5°C, N,N-diisopropylethylamine is added, and then the mixture is stirred at -5-5°C for reaction. After the reaction is complete, the o-dichlorobenzene is removed by distillation under reduced pressure, and the concentrated mother liquor is collected and purified to obtain a light yellow solid powder, which is the compound represented by the general formula B-2.

9. Use of the six-membered and seven-membered boron nitrogen heterocyclic derivative based on a heavy atom fusion donor as claimed in any one of claims 1 to 4 in an organic electroluminescent device.

10. The use according to claim 9, characterized in that: The electroluminescent device comprises in sequence: an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode; the light-emitting layer comprises the six-membered and seven-membered boron nitrogen heterocyclic derivative; Preferably, an exciton blocking layer is provided between the hole transport layer and the light-emitting layer, and between the light-emitting layer and the electron transport layer; The six-membered and seven-membered boron nitrogen heterocyclic derivatives based on heavy atom fusion donors are specifically used as guest luminescent materials and / or sensitizer materials.

Images