Boron-containing seven-membered fused ring compound and application thereof

Abstract

The invention belongs to the technical field of organic electroluminescent materials, and relates to a boron-containing seven-membered fused ring compound and application thereof. According to the boron-containing seven-membered fused ring compound provided by the invention, a double-naphthalene ring and a boron atom form a seven-membered ring, the seven-membered ring and an N or O atom form a ring at an adjacent position to form a large-conjugate rigid plane structure, an electron donating or electron withdrawing group is introduced at a specific position for modification, the distorted conformation at the periphery of a molecule is adjusted, and the compound has a large-conjugate rigid structure. According to the present invention, the organic light-emitting diode compound inhibits the close packing generated due to the pi-pi effect among molecules, obtains the high external quantum efficiency, has characteristics of high decomposition temperature, suitable energy level and color coordinate, and good color purity, can be used as the blue light doping in the organic light-emitting device, and can be used for the organic light-emitting device, such that the organic light-emitting device can be used for the organic light-emitting device. And the device performance of the organic light-emitting device can be obviously improved.

Description

Technical Field

[0001] The invention belongs to the technical field of organic electroluminescent materials and relates to a boron-containing seven-membered condensed ring compound and application thereof. Background Art

[0002] Organic light-emitting diodes (OLEDs), as an efficient technology that directly converts electrical energy into light energy, have been widely used in the fields of display and lighting. The luminescence mechanism of OLEDs is based on the special properties of organic semiconductor materials driven by a DC electric field, which can produce a rich variety of colors, including individual red, green, blue, yellow light and even combined white light, providing a broad space for modern display technology. According to different light-emitting principles, OLED elements are subdivided into two categories: fluorescent and phosphorescent. Traditionally, fluorescent OLEDs emit light by utilizing singlet excitons, but due to the statistical laws of electron spins, their internal quantum efficiency can only reach 25%, which limits the improvement of energy conversion efficiency. In order to overcome this limitation, researchers have explored and developed thermally activated delayed fluorescence (TADF) materials. As the third generation of organic light-emitting materials, TADF materials enable triplet excitons to be efficiently converted into singlet excitons through a unique singlet-triplet energy level difference regulation mechanism, which can theoretically achieve an internal quantum efficiency close to 100%, while showing the diversity and stability advantages of material structure.

[0003] Although TADF materials have made significant breakthroughs in efficiency, existing studies have pointed out that they still face the challenge of unsatisfactory device life in practical applications, which has become one of the key factors restricting the further development of OLED technology. In recent years, in order to optimize the performance of TADF materials, scientists have continuously explored new material systems. Among them, the boron-nitrogen series TADF molecules developed by Kwansei Gakuin University in Japan have attracted widespread attention for their unique molecular structure. These molecules introduce adjacent boron atoms and nitrogen atoms and use the opposite resonance effect between them to significantly change the HOMO / LUMO distribution of the molecules, achieving narrow-band emission characteristics, which is specifically manifested in a significant reduction in the half-peak width of the emission spectrum and a reduction in the Stokes shift. This molecular design not only improves the spectral purity, but also further enhances the luminous efficiency and stability of the material by reducing the deformation of the electron cloud structure and the relaxation of molecular vibrations. It is particularly noteworthy that the blue light materials widely used in current OLED products are still mostly traditional fluorescent materials. Compared with red and green light materials, the luminous efficiency and stability of blue light materials are still insufficient, and it is difficult to achieve ideal color purity. Therefore, developing more blue light materials to improve the overall efficiency, stability and color performance of OLED devices has become a key issue that needs to be urgently addressed in the industry, and is of great significance for promoting the overall advancement of OLED technology. Summary of the invention

[0004] In order to overcome the above technical problems, the present invention provides a class of boron-containing seven-membered fused ring compounds, wherein a binaphthalene ring and a boron atom form a seven-membered ring, and further form a ring with N or O atoms at adjacent positions to form a large conjugated rigid planar structure, electron-donating or electron-withdrawing groups are introduced at specific positions for modification, the distorted conformation of the molecule periphery is adjusted, the close stacking between molecules due to π-π effects is suppressed, and a higher external quantum efficiency is obtained. The compounds have a very high decomposition temperature and a suitable orbital energy level, and can be applied as a luminescent material to an organic electroluminescent device, reduce the driving voltage, improve the external quantum efficiency and color purity, and significantly improve the device performance of the organic electroluminescent device.

[0005] In one aspect, the present invention relates to a compound having a structure as shown in formula (I):

[0006]

[0007] Wherein, X is NR4 or O, and Y is NR5 or O;

[0008] R1 to R5 are independently selected from one or a combination of hydrogen, halogen, substituted or unsubstituted C6 to C60 aromatic group, substituted or unsubstituted C6 to C60 aromatic amino group, substituted or unsubstituted heteroaryl group containing N, O, S and having carbon number of C2 to C60;

[0009] A, B, C, and D each independently represent an acene ring or are absent;

[0010] Any hydrogen atom may be replaced by deuterium or not.

[0011] Furthermore, in the compound provided by the present invention, it has a structure as shown in any one of formula (1) to formula (3),

[0012]

[0013] Furthermore, in the compounds provided by the present invention, R1 to R5 are independently selected from one or a combination of two of methyl, ethyl, tert-butyl, phenyl, naphthyl, biphenyl, anthracenyl, phenanthryl, pyrene, fluoranthene, pyridyl, pyrrolyl, pyranyl, pyrimidinyl, triazine, pyrazinyl, quinolyl, dibenzofuranyl, dibenzothiophenyl, dibenzocarbazolyl, 9,9-diphenylfluorenyl, 9,9-dimethylfluorenyl, spirofluorenyl, silafluorenyl, and amine.

[0014] Furthermore, in the compounds provided by the present invention, adjacent R1 and R5, and / or adjacent R3 and R4, form a substituted or unsubstituted ring;

[0015] For example, the adjacent R1 and R5, and the adjacent R3 and R4 form a ring having a structure of formula (4)-formula (5),

[0016]

[0017] Furthermore, in the compounds provided by the present invention, any of the following structures is present:

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029] In another aspect, the present invention relates to an organic electroluminescent device, comprising a fluorescent light-emitting material, wherein the fluorescent light-emitting material comprises the compound.

[0030] In another aspect, the present invention relates to an organic electroluminescent device, comprising a light-emitting layer material, wherein the light-emitting layer material comprises the compound.

[0031] In another aspect, the present invention relates to the use of the compound in an organic electroluminescent device.

[0032] In another aspect, the present invention relates to the use of the compound in an organic electroluminescent device.

[0033] Furthermore, in the application provided by the present invention, the compound has at least one function of reducing driving voltage, improving external quantum efficiency, and improving color purity.

[0034] The compound, the luminescent material prepared from the compound, and the luminescent device prepared from the luminescent material can all be used for organic electroluminescent devices and display devices. It should be noted that the luminescent material and the luminescent device both contain the compound provided by the present invention, but this does not limit the scope of use of the compound provided by the present invention, and the compound may also be used for the manufacture of other devices. Therefore, any manufacture or use using the compound provided by the present invention as a raw material should fall within the protection scope determined by the present invention.

[0035] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages:

[0036] The boron-containing seven-membered fused ring compound shown in formula (I) provided by the present invention has a seven-membered ring formed by a binaphthalene ring and a boron atom, and is further ringed with N or O atoms at adjacent positions to form a large conjugated rigid planar structure. An electron-donating or electron-withdrawing group is introduced at a specific position for modification, so as to adjust the distorted conformation of the molecule periphery, prevent π-π stacking between molecules, and obtain a higher external quantum efficiency. The compound has a very high decomposition temperature, and further improves the luminous efficiency of an organic electroluminescent device. Experimental verification shows that the series of compounds have shown relatively excellent performance as luminescent materials in organic electroluminescent devices, reduce driving voltage, improve luminous efficiency, and have a narrow half-peak width. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 Schematic diagram of the structure of an organic electroluminescent element.

[0039] Among them, 1 is the substrate, 2 is the anode layer, 3 is the hole injection layer, 4 is the first hole transport layer, 5 is the second hole transport layer, 6 is the light emitting layer, 7 is the hole blocking layer, 8 is the electron transport layer, 9 is the electron injection layer, and 10 is the cathode layer. DETAILED DESCRIPTION

[0040] The technical scheme of the present invention is described below in conjunction with the examples, but the present invention is not limited to the following examples. The experimental methods and detection methods described in each example are conventional methods unless otherwise specified; the reagents and materials are available on the market unless otherwise specified, and the % in the following examples are all mass percentages unless otherwise specified.

[0041] Preparation Example

[0042] The synthesis methods of some intermediates and compounds are provided below. The synthesis methods of the remaining intermediates and compounds are similar and can be easily synthesized. The specific synthesis routes are shown below.

[0043] Synthesis of compound 1-1:

[0044]

[0045] Synthesis of intermediate 1-2: Under nitrogen protection, add intermediate 1-1 (100g, 240mmol), aniline (50g, 540mmol), Pd2(dba)3 (tri(dibenzylideneacetone)dipalladium, 4g, 4mmol), P(t-Bu)3 (tri-tert-butylphosphine, 2g, 10mmol), DBU (1,8-diazabicyclo[5.4.0]undec-7-ene, 7g, 50mmol), sodium tert-butoxide (180g, 1.9mol), 1500mL of toluene solvent, stir and reflux at 110°C for 2h. After the reaction is complete, the reaction solution is cooled to room temperature, washed with water until neutral, the organic phase is dried with anhydrous 100g magnesium sulfate for 3h and filtered, and the filtrate is purified by silica gel column to obtain 84.7g of intermediate 1-2, with a yield of 81%.

[0046] Synthesis of intermediate 1-3: Under nitrogen protection, add intermediate 1-2 (21.8 g, 50 mmol), 1,3-dibromo-2-chlorobenzene (13.4 g, 50 mmol), copper powder (5.1 g, 50 mmol), K2CO3 (20.7 g, 150 mmol), and 400 ml of DMF solvent into a three-necked flask, stir and heat to reflux reaction for 8 hours, then cool to room temperature, filter the reaction solution, pour the filtrate into 7 L of water while stirring, and a large amount of yellow solid precipitates. After stirring for 30 minutes, filter and recrystallize the filter cake with toluene to obtain 21.2 g of intermediate 1-3 with a yield of 80%.

[0047] Synthesis of compound 1-1: Under nitrogen protection, add intermediate 1-3 (10.6g, 20mmol) and xylene (150mL) to the reaction bottle in sequence, and cool the system to -75°C with liquid nitrogen. Add tert-butyl lithium (25mL, 40mmol, 1.6M) dropwise to the system. After the addition is complete, heat to 0°C and continue to stir and react for 2h. Then cool the system to -50°C to -40°C, and then add boron tribromide (15g, 60mmol). After the addition is complete, continue to react at -50°C for 2h. Then heat the system to 0°C, add DIEA (N,N-diisopropylethylamine 7.7g, 60mmol), and gradually heat to 120°C after the addition is complete. Continue to react for 10h. After the reaction is completed, evaporate the solvent under reduced pressure, and the crude product is beaten with ethanol and recrystallized from toluene / ethanol to obtain 3.1g of compound 1-1, with a yield of 30%. The results of mass spectrometry of the obtained sample are: HR-MS (APCI): m / z 518.1954 [M+H] + ; C 38 H 23 BN2 (%) calculated value: C, 88.0392; H, 4.4720; B, 2.0852; N, 5.4037; measured value: C, 88.0369; H, 4.4746; B, 2.0839; N, 5.4046;

[0048] Synthesis of compound 1-11:

[0049]

[0050] Synthesis of intermediate 1-5: Under nitrogen protection, add intermediate 1-4 (34.0 g, 240 mmol), NBS (N-bromosuccinimide, 89.0 g, 500 mmol), and 1000 ml of chloroform solvent into a three-necked flask, stir and react at room temperature for 2 h, wash the reaction solution with water, dry it, concentrate it, add ethanol to disperse it, and filter it to obtain 56.5 g of intermediate 1-5, with a yield of 79%.

[0051] Synthesis of intermediate 1-6: Under nitrogen protection, intermediate 1-5 (29.8 g, 100 mmol), 2-bromophenylboronic acid (40.0 g, 200 mmol), Pd(PPh3)4 (tetrakis(triphenylphosphine)palladium, 4.6 g, 4 mmol), K2CO3 (potassium carbonate, 55.2 g, 400 mmol), TBAB (tetrabutylammonium bromide, 6.5 g, 20 mmol), toluene (400 mL), ethanol (200 mL), water (100 mL) were added to a three-necked flask, heated to 76 ° C and stirred for 8 h, then cooled to room temperature, washed with water until neutral, the organic phase was dried over anhydrous magnesium sulfate, passed through a silica gel column, and then purified by recrystallization from toluene to obtain 33.7 g of intermediate 1-6, with a yield of 75%.

[0052] The synthesis method of intermediate 1-7 refers to the synthesis of intermediate 1-3, except that intermediate 1-2 and 1,3-dibromo-2-chlorobenzene are replaced by intermediate 1-6, with a yield of 68%.

[0053] The synthesis method of intermediate 1-8 refers to the synthesis of intermediate 1-3, except that intermediate 1-2 and 1,3-dibromo-2-chlorobenzene are replaced by intermediate 1-1 and intermediate 1-7, with a yield of 77%.

[0054] The synthesis of compound 1-11 was based on the synthesis of compound 1-1, except that intermediate 1-3 was replaced by intermediate 1-8, with a yield of 32%. The mass spectrometry results of the obtained sample were: HR-MS (APCI): m / z 514.1641 [M+H] + ; C 38 H 19 BN2 (%) calculated value: C, 88.7293; H, 3.7232; B, 2.1015; N, 5.4460; measured value: C, 88.7282; H, 3.7234; B, 2.1012; N, 5.4472;

[0055] Synthesis of compound 1-21:

[0056]

[0057]

[0058] Synthesis of intermediate 1-10: Under nitrogen protection, add intermediate 1-9 (128.0 g, 500 mmol) and 1000 mL of tetrahydrofuran solvent to the reaction bottle, and cool the system to -78 ° C with liquid nitrogen, add tert-butyl lithium (375 mL, 600 mmol, 1.6 M) dropwise to the system, and after the addition is complete, heat to 10 ° C and continue to stir and react for 3 hours, and then heat to 50 ° C and continue to react for 3 hours. After the reaction is completed, cool to room temperature, pour into a large amount of ice water while stirring to precipitate solids. Filter, and the filter cake is slurried with ethanol and recrystallized with toluene / ethanol to obtain 95.6 g of intermediate 1-10, with a yield of 75%.

[0059] The synthesis method of intermediate 1-11 refers to the synthesis of intermediate 1-2, except that intermediate 1-1 is replaced by intermediate 1-10, with a yield of 80%.

[0060] The synthesis method of intermediate 1-12 refers to the synthesis of intermediate 1-3, except that intermediate 1-2 is replaced by intermediate 1-11, with a yield of 70%.

[0061] The synthesis method of compound 1-21 refers to the synthesis of compound 1-1, and intermediate 1-3 is replaced by intermediate 1-12, with a yield of 32%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 618.2267 [M+H] + ; C 46 H 27 BN2(%) calculated value: C, 89.3233; H, 4.4000; N, 4.5290; B, 1.7476; found value: C, 89.3248; H, 4.4013; N, 4.5296; B, 1.7443.

[0062] Synthesis of compound 1-31:

[0063]

[0064] The synthesis method of intermediate 1-13 refers to the synthesis of intermediate 1-3, replacing intermediate 1-2 and 1,3-dibromo-2-chlorobenzene with intermediate 1-10 and intermediate 1-7, with a yield of 73%.

[0065] The synthesis method of compound 1-31 refers to the synthesis of compound 1-1, and intermediate 1-3 is replaced by intermediate 1-13, with a yield of 28%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 614.1954 [M+H] + ; C 46 H 23 BN2(%) calculated value: C, 89.9094; H, 3.7727; N, 4.5587; B, 1.7591; found value: C, 89.9068; H, 3.7762; N, 4.5593; B, 1.7577.

[0066] Synthesis of compound 1-41:

[0067]

[0068] The synthesis method of intermediate 1-16 refers to the synthesis of intermediate 1-6, except that intermediate 1-5 and 2-bromophenylboronic acid are replaced by intermediate 1-14 and intermediate 1-15, with a yield of 82%.

[0069] The synthesis of intermediate 1-17 refers to the synthesis of intermediate 1-2, except that intermediate 1-1 is replaced by intermediate 1-16, with a yield of 78%.

[0070] The synthesis of intermediate 1-18 refers to the synthesis of intermediate 1-3, except that intermediate 1-2 is replaced by intermediate 1-17, with a yield of 74%.

[0071] The synthesis method of compound 1-41 refers to the synthesis of compound 1-1, and intermediate 1-3 is replaced by intermediate 1-18, with a yield of 32%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 618.2267 [M+H] + ; C 46 H 27 BN2(%) calculated value: C, 89.3233; H, 4.4000; N, 4.5290; B, 1.7476; found value: C, 89.3258; H, 4.4010; N, 4.5286; B, 1.7446.

[0072] Synthesis of compound 1-6:

[0073]

[0074] The synthesis method of intermediate A-2 refers to the synthesis of intermediate 1-6, except that intermediate 1-5 and 2-bromobenzeneboronic acid are replaced by intermediate A-1 and intermediate 1,3-dibromo-2-chloro-5-iodobenzene, with a yield of 80%.

[0075] The synthesis method of intermediate A-4 refers to the synthesis of intermediate 1-2, except that aniline is replaced by intermediate A-3, with a yield of 78%.

[0076] The synthesis method of intermediate A-5 refers to the synthesis of intermediate 1-3, except that intermediate 1-2 and 1,3-dibromo-2-chlorobenzene are replaced by intermediate A-2 and intermediate A-4, with a yield of 68%.

[0077] The synthesis method of compound 1-6 refers to the synthesis of compound 1-1, and intermediate 1-3 is replaced by intermediate A-5, with a yield of 28%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 638.6756 [M+H] + ; C 46 H 15 D 16 BN2(%) calculated value: C, 86.5067; H, 2.3673; D, 5.0473; N, 4.3862; B, 1.6925; measured value: C, 86.5083; H, 2.3679; D, 5.0481; N, 4.3845; B, 1.6912.

[0078] Synthesis of compound 1-14:

[0079]

[0080] The synthesis method of intermediate B-2 refers to the synthesis of intermediate 1-6, except that intermediate 1-5 and 2-bromophenylboronic acid are replaced by intermediate B-1 and intermediate o-nitrophenylboronic acid, with a yield of 77%.

[0081] Synthesis of intermediate B-3: Under nitrogen protection, add intermediate B-2, PPh3 (triphenylphosphine), and o-dichlorobenzene to a three-necked flask, heat and stir at 160°C for 20 hours. After cooling the reaction solution to room temperature (24°C), add n-heptane to precipitate white crystals, filter, and then recrystallize and purify with toluene to obtain intermediate B-3 with a yield of 82%.

[0082] The synthesis method of intermediate B-4 refers to the synthesis of intermediate 1-3, replacing intermediate 1-2 and intermediate 1,3-dibromo-2-chlorobenzene with intermediate 1-1 and intermediate B-3, with a yield of 75%.

[0083] Synthesis of intermediate B-5: Under nitrogen protection, add intermediate B-3, pyridine, and dichloroethane solvent into a three-necked flask, cool the system to 0°C, slowly add trifluoromethanesulfonic anhydride, stir and react for 3 hours after the addition is complete, add saturated Na2CO3 aqueous solution to neutralize, repeatedly wash with water until neutral, dry and filter the organic phase, purify with silica gel column, and purify by recrystallization from toluene / ethanol to obtain intermediate B-5 with a yield of 85%.

[0084] The synthesis method of intermediate B-7 refers to the synthesis of intermediate 1-2, except that intermediate 1-1 and intermediate aniline are replaced by intermediate B-5 and intermediate B-6 (diphenylamine), with a yield of 86%.

[0085] The synthesis method of compound 1-14 refers to the synthesis of compound 1-1, and intermediate 1-3 is replaced by intermediate B-7, with a yield of 31%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 681.2376 [M+H] + ; C 50 H 28 BN3 (%) calculated value: C, 88.1082; H, 4.1408; N, 6.1650; B, 1.5860; found value: C, 88.1092; H, 4.1387; N, 6.1644; B, 1.5877.

[0086] By referring to the synthesis methods of compounds 1-6 and 1-14, a series of compounds of the general formula (1) and general formula (4) can be prepared. The only difference is that different intermediates need to be replaced according to different products, and intermediate A-1, intermediate A-3 and intermediate B-6 are replaced respectively, and the mass amount of the compound is changed according to the different molar amounts.

[0087] Synthesis of compound 2-1:

[0088]

[0089] Synthesis of intermediate 2-2: Under nitrogen protection, intermediate 2-1 (57.2 g, 200 mmol), 1,3-difluoro-2-chlorobenzene (29.6 g, 200 mmol), cesium carbonate (130.3 g, 400 mmol) and 1000 mL of DMF solvent were added to the reaction bottle in sequence, and heated to reflux for reaction for 6 h, then the system was cooled to room temperature, the reaction solution was filtered, 1500 ml of water was added to the filtrate while stirring, a white precipitate was generated, filtered, and the filter cake was washed with water and ethanol in sequence to obtain a crude product, and then the crude product was recrystallized from toluene / ethanol to obtain 55.9 g of intermediate 2-2 with a yield of 71%.

[0090] The synthesis method of compound 2-1 refers to the synthesis of compound 1-1, and intermediate 1-3 is replaced by intermediate 2-2, with a yield of 32%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 368.1009 [M+H] + ; C 26 H 13 BO2(%) calculated value: C, 84.8147; H, 3.5590; B, 2.9359; O, 8.6904; found value: C, 84.8161; H, 3.5569; B, 2.9345; O, 8.6925;

[0091] Synthesis of compound 2-11:

[0092]

[0093] Synthesis of intermediate 2-3: Under nitrogen protection, add intermediate 1-10 (153.0 g, 300 mmol), CuI (5.7 g, 30 mmol), KOH (56.4 g, 600 mmol), TBAB (tetrabutylammonium bromide, 9.7 g, 30 mmol), 6,7-dihydroquinolin-8 (5H) -one (4.4 g, 30 mmol), 800 ml of DMF solvent to a three-necked flask, heat to 120 ° C and stir to react for 20 h, then cool to room temperature, add 1000 ml of dichloroethane for extraction and wash with water until neutral, the organic phase is dried over anhydrous magnesium sulfate and then passed through a silica gel column, and then recrystallized and purified from toluene / ethanol to obtain 82.2 g of intermediate 2-3, with a yield of 71%;

[0094] The synthesis method of intermediate 2-4 refers to the synthesis of intermediate 2-2, except that intermediate 2-1 is replaced by intermediate 2-3, with a yield of 70%;

[0095] The synthesis method of compound 2-11 refers to the synthesis of compound 1-1, and intermediate 1-3 is replaced by intermediate 2-4, with a yield of 34%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 468.1322 [M+H] +; C 34 H 17 BO2 (%) calculated value: C, 87.2002; H, 3.6591; B, 2.3083; O, 6.8325; found value: C, 87.2046; H, 3.6558; B, 2.3067; O, 6.8329;

[0096] Synthesis of compound 2-6:

[0097]

[0098] The synthesis method of intermediate C-1 refers to the synthesis of intermediate 2-2, except that the intermediate 1,3-difluoro-2-chlorobenzene is replaced by the intermediate 5-bromo-2-chloro-1,3-difluorobenzene, with a yield of 78%.

[0099] The synthesis method of intermediate C-3 refers to the synthesis of intermediate 1-6, except that intermediate 1-5 and 2-bromophenylboronic acid are replaced by intermediate C-1 and intermediate C-2, with a yield of 80%.

[0100] The synthesis method of compound 2-6 refers to the synthesis of compound 1-1, and intermediate 1-3 is replaced by intermediate C-3, with a yield of 30%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 620.1948 [M+H] + ; C 46 H 25 BO2 (%) calculated value: C, 89.0401; H, 4.0611; B, 1.7421; O, 5.1567; found value: C, 89.0475; H, 4.0580; B, 1.7401; O, 5.1544

[0101] By referring to the synthesis method of compound 2-6, a series of compounds of the general formula (2) can be prepared. The only difference is that different intermediates need to be used to replace intermediate C-2 according to different products, and the mass amount of the compound can be changed according to different molar amounts.

[0102] Synthesis of compound 3-1:

[0103]

[0104]

[0105] The synthesis method of intermediate 3-2 refers to the synthesis of intermediate 1-2, except that intermediate 1-1 is replaced by intermediate 3-1, and the yield is 81%.

[0106] The synthesis method of intermediate 3-4 refers to the synthesis of intermediate 2-2, except that intermediate 2-1 and 1,3-difluoro-2-chlorobenzene are replaced by intermediate 3-2 and intermediate 3-3, with a yield of 77%.

[0107] The synthesis method of intermediate 3-5 refers to the synthesis of intermediate 1-8, replacing intermediate 1-1 and intermediate 1-7 with intermediate 3-4, with a yield of 73%.

[0108] The synthesis method of compound 3-1 refers to the synthesis of compound 1-1, and intermediate 1-3 is replaced by intermediate 3-5, with a yield of 32%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 443.1481 [M+H] + ; C 32 H 18 OBN (%) calculated value: C, 86.7001; H, 4.0928; O, 3.6090; N, 3.1596; B, 2.4385; found value: C, 86.7023; H, 4.0916; O, 3.6088; N, 3.1582; ​​B, 2.4391.

[0109] Synthesis of compound 3-16:

[0110]

[0111] The synthesis method of intermediate 3-7 refers to the synthesis of intermediate 2-2, except that intermediate 2-1 and 1,3-difluoro-2-chlorobenzene are replaced by intermediate 3-3 and intermediate 3-6, with a yield of 79%.

[0112] The synthesis method of intermediate 3-8 refers to the synthesis of intermediate 1-8, replacing intermediate 1-1 and intermediate 1-7 with intermediate 3-7, with a yield of 75%.

[0113] The synthesis method of compound 3-16 refers to the synthesis of compound 1-1, and intermediate 1-3 is replaced by intermediate 3-8, with a yield of 27%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 441.1325 [M+H] + ; C 32 H 16 OBN (%) calculated value: C, 87.0962; H, 3.6547; O, 3.6255; N, 3.1741; B, 2.4496; found value: C, 87.0979; H, 3.6540; O, 3.6242; N, 3.1758; B, 2.4481.

[0114] Synthesis of compound 3-31:

[0115]

[0116] Synthesis of intermediate 3-9: Under nitrogen protection, add intermediate 1-10 (153.0 g, 300 mmol) and 1000 mL of THF to a three-necked flask, cool the system to -78 ° C with liquid nitrogen, add tert-butyl lithium (94 mL, 150 mmol, 1.6 M) dropwise to the system, keep -78 ° C and continue to stir the reaction for 2 h after the addition is complete, then add Selectfluor (fluorine reagent, 53.1 g, 150 mmol). After the addition is complete, warm the system to room temperature and continue to stir the reaction for 2 h. After the reaction is completed, add 50 ml of saturated ammonium chloride solution to quench the reaction, evaporate the solvent under reduced pressure, and the crude product is slurried with ethanol and recrystallized with toluene / n-heptane to obtain 108 g of intermediate 3-9 with a yield of 80%.

[0117] The synthesis method of intermediate 3-10 refers to the synthesis of intermediate 2-2, except that intermediate 2-1 and 1,3-difluoro-2-chlorobenzene are replaced by intermediate 3-9 and intermediate 3-2, with a yield of 74%.

[0118] The synthesis method of intermediate 3-11 refers to the synthesis of intermediate 1-3, replacing intermediate 1-2 and 1,3-dibromo-2-chlorobenzene with intermediate 3-10, with a yield of 78%.

[0119] The synthesis method of compound 3-31 refers to the synthesis of compound 1-1, and intermediate 1-3 is replaced by intermediate 3-11, with a yield of 31%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 543.1794 [M+H] + ; C 40 H 22 OBN (%) calculated value: C, 88.4085; H, 4.0807; O, 2.9441; N, 2.5775; B, 1.9892; measured value: C, 88.4066; H, 4.0818; O, 2.9437; N, 2.5791; B, 1.9888.

[0120] Synthesis of compound 3-46:

[0121]

[0122]

[0123] The synthesis method of intermediate 3-12 refers to the synthesis of intermediate 2-2, replacing intermediate 2-1 and 1,3-difluoro-2-chlorobenzene with intermediate 3-9 and intermediate 3-6, with a yield of 78%.

[0124] The synthesis method of intermediate 3-13 refers to the synthesis of intermediate 1-3, replacing intermediate 1-2 and 1,3-dibromo-2-chlorobenzene with intermediate 3-12, with a yield of 70%.

[0125] The synthesis method of compound 3-46 refers to the synthesis of compound 1-1, and intermediate 1-3 is replaced by intermediate 3-13, with a yield of 30%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 541.1638 [M+H] + ; C 40 H 20 OBN (%) calculated value: C, 88.7377; H, 3.7236; O, 2.9550; N, 2.5871; B, 1.9966; found value: C, 88.7390; H, 3.7232; O, 2.9538; N, 2.5883; B, 1.9957.

[0126] Synthesis of compound 3-2:

[0127]

[0128] The synthesis method of intermediate D-2 refers to the synthesis of intermediate 1-2, except that intermediate 1-1 and intermediate aniline are replaced by intermediate D-1 and intermediate 5-bromo-2-chloro-3-iodophenol, with a yield of 85%.

[0129] The synthesis method of intermediate D-3 refers to the synthesis of intermediate 2-2, except that intermediate 2-1 and 1,3-difluoro-2-chlorobenzene are replaced by intermediate D-2 and intermediate 3-3, with a yield of 77%.

[0130] The synthesis method of intermediate D-4 refers to the synthesis method of intermediate 1-8, except that intermediate 1-1 and intermediate 1-7 are replaced by intermediate D-3, with a yield of 78%.

[0131] The synthesis method of intermediate D-6 refers to the synthesis of intermediate 1-6, replacing intermediate 1-5 and 2-bromophenylboronic acid with intermediate D-4 and intermediate D-5 (1,3-bis(2-methylprop-2-yl)benzene), with a yield of 84%.

[0132] The synthesis method of compound 3-2 refers to the synthesis of compound 1-1, and intermediate 1-3 is replaced by intermediate D-6, with a yield of 30%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 743.4298 [M+H] + ; C 54 H 54 BNO2(%) calculated value: C, 87.1951; H, 7.3177; B, 1.4533; O, 2.1509; N, 1.8831; found value: C, 87.1977; H, 7.3140; B, 1.4524; O, 2.1551; N, 1.8808.

[0133] Synthesis of compound 3-23:

[0134]

[0135] The synthesis method of intermediate E-2 refers to the synthesis of intermediate 1-6, except that intermediate 1-5 and 2-bromophenylboronic acid are replaced by intermediate E-1 and intermediate 5-bromo-2-chloro-4-iodophenol, with a yield of 83%.

[0136] The synthesis method of intermediate E-3 refers to the synthesis of intermediate B-3, except that intermediate B-2 is replaced by intermediate E-2, with a yield of 85%.

[0137] The synthesis method of intermediate E-4 refers to the synthesis of intermediate 2-2, except that intermediate 2-1 and intermediate 1,3-difluoro-2-chlorobenzene are replaced by intermediate 3-3 and E-3, with a yield of 74%.

[0138] The synthesis method of intermediate E-5 refers to the synthesis method of intermediate 1-8, replacing intermediate 1-1 and intermediate 1-7 with intermediate E-4, with a yield of 75%.

[0139] The synthesis method of intermediate E-7 refers to the synthesis of intermediate 1-6, replacing intermediate 1-5 and 2-bromophenylboronic acid with intermediate E-5 and intermediate E-6 ((4,6-diphenyl-1,3,5-triazine-2-yl)boronic acid), with a yield of 83%.

[0140] The synthesis method of compound 3-23 refers to the synthesis of compound 1-1, and intermediate 1-3 is replaced by intermediate E-7, with a yield of 29%. The result of mass spectrometry detection of the obtained sample is: HR-MS (APCI): m / z 672.2121 [M+H] + ; C 47 H 25 BN4O (%) calculated value: C, 83.9363; H, 3.7469; B, 1.6073; O, 2.3788; N, 8.3306; found value: C, 83.9385; H, 3.7411; B, 1.6039; O, 2.3790; N, 8.3375.

[0141] By referring to the synthesis methods of compound 3-2 and compound 3-23, a series of compounds of the general formula (3) and general formula (5) can be prepared. The only difference is that different intermediates need to be replaced according to different products, and intermediate D-1, intermediate D-5 and intermediate E-6 are replaced respectively, and the mass amount of the compound is changed according to the different molar amounts.

[0142] Device Embodiment

[0143] Embodiment 1 provides an organic electroluminescent device, the structure of which is as follows: Figure 1As shown, it includes a substrate 1, an anode layer 2, a hole injection layer 3, a first hole transport layer 4, a second hole transport layer 5, a light emitting layer 6, a hole blocking layer 7, an electron transport layer 8, an electron injection layer 9 and a cathode layer 10 which are stacked in sequence.

[0144] Among them, the material of the anode layer 2 is indium tin oxide (ITO) with a high work function, the material of the hole injection layer 3 is HAT-CN with a thickness of 5nm; the material of the first hole transport layer 4 is NPB with a thickness of 50nm; the material of the second hole transport layer 5 is TCTA with a thickness of 15nm; the light-emitting layer 6 uses H1 as the main material and compound 1-1 as the light-emitting material, with a doping mass ratio of 3% and a thickness of 30nm; the material of the hole blocking layer 7 is TPBI with a thickness of 10nm; the material of the electron transport layer 8 is ET-1 with a thickness of 35nm; the material of the electron injection layer 9 is Liq with a thickness of 2nm; the material of the cathode layer is Al with a thickness of 100nm.

[0145] The basic material structure used in each functional layer of the device is as follows:

[0146]

[0147] The specific preparation steps of the above organic electroluminescent device are as follows:

[0148] 1) Clean the ITO anode on the transparent glass or plastic substrate by ultrasonic cleaning with deionized water, acetone, and ethanol for 20 minutes each, and then perform plasma treatment in an oxygen atmosphere for 5 minutes;

[0149] 2) On the ITO anode layer, a hole injection layer material HAT-CN is deposited by vacuum evaporation with a thickness of 5 nm, which serves as a hole injection layer;

[0150] 3) depositing a hole transport material NPB on the hole injection layer by vacuum evaporation with a thickness of 50 nm, and this layer serves as the first hole transport layer;

[0151] 4) Vacuum evaporation of hole transport material TCTA on the first hole transport layer NPB with a thickness of 15 nm, which serves as the second hole transport layer;

[0152] 5) On the second hole transport layer, a light-emitting layer was co-deposited by vacuum evaporation, using H1 as the main material and compound 1-1 as the light-emitting material, with a doping mass ratio of 3% and a thickness of 30 nm;

[0153] 6) On the light-emitting layer, a hole blocking material TPBI is deposited by vacuum evaporation with a thickness of 10 nm, and this layer serves as a hole blocking layer;

[0154] 7) On the hole blocking layer, the electron transport material ET-1 is deposited by vacuum evaporation with a thickness of 35 nm, and this layer serves as the electron transport layer;

[0155] 8) On the electron transport layer, the electron injection material Liq is evaporated by vacuum evaporation with a thickness of 2 nm, and this layer serves as the electron injection layer;

[0156] 9) On the electron injection layer, cathode Al is deposited by vacuum evaporation with a thickness of 100 nm. This layer is used as a cathode conductive electrode.

[0157] Embodiment 2 to Embodiment 20

[0158] The implementation process is the same as that of Example 1, except that the luminescent material is replaced by other developed compounds instead of compound 1-1.

[0159] Device Comparison

[0160] The implementation process is the same as that of device embodiment 1, except that BD01 is used as the light-emitting material instead of compound 1-1.

[0161] The cathode and anode of each group of organic electroluminescent devices were connected by a known driving circuit, and the voltage-efficiency-brightness relationship of the OLED device was tested by a standard method using a Keithley 2400 power supply combined with a PR670 photometer. The test results are shown in Table 1.

[0162] Table 1: Comparison of performance results of organic electroluminescent devices in each group

[0163]

[0164]

[0165] As shown in Table 1, compared with the compound BD01 which is also a boron nitrogen system, the compounds provided by the present invention are applied to OLED devices as luminescent doping materials, and the performance is improved. For example, the compounds 1-33 and 2-17 in device Examples 6 and 13 are used as blue light doping materials. Compared with BD01 in the comparative example, the external quantum efficiency and half-peak width are significantly improved, and the external quantum efficiency is increased by 48%, and the half-peak width is also significantly reduced. It can be seen that the compounds of the present invention are selected, which have a large conjugated structure containing a seven-membered boron ring and a narrow half-peak width. Compared with the existing materials applied to OLED light-emitting devices, the external quantum efficiency and other photoelectric properties of the devices are all well performed, and the synthesis process of the materials is simple, which has great application value in the application of OLED devices and has good industrialization prospects.

[0166] The invention provides a boron-containing seven-membered fused ring compound, wherein a binaphthalene ring and a boron atom form a seven-membered ring, and further form a ring with N or O atoms at adjacent positions to form a large conjugated rigid planar structure, electron-donating or electron-withdrawing groups are introduced at specific positions for modification, the distorted conformation of the molecule periphery is adjusted, the close stacking between molecules due to π-π interaction is suppressed, and higher external quantum efficiency is obtained. The compound has a very high decomposition temperature and a suitable orbital energy level, and can be applied as a luminescent material to an organic electroluminescent device, reduce the driving voltage, improve the external quantum efficiency and color purity, and significantly improve the device performance of the organic electroluminescent device.

[0167] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, they are also intended to be included.

[0168] As described above, the basic principle, main features and advantages of the present invention are well described. The above embodiments and descriptions are only descriptions of the preferred implementation modes of the present invention, and the present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, various changes and improvements made by ordinary technicians in this field to the technical solution of the present invention should fall within the protection scope determined by the present invention.

Claims

1. A compound, characterized in that Having a structure as shown in formula (I), Wherein, X is NR4 or O, and Y is NR5 or O; R1 to R5 are independently selected from one or a combination of hydrogen, halogen, substituted or unsubstituted C6 to C60 aromatic group, substituted or unsubstituted C6 to C60 aromatic amino group, substituted or unsubstituted heteroaryl group containing N, O, S and having carbon number of C2 to C60; A, B, C, and D each independently represent an acene ring or are absent; Any hydrogen atom may be replaced by deuterium or not.

2. The compound according to claim 1, characterized in that Having a structure as shown in any one of formulas (1) to (3), 3. The compound according to claim 1, characterized in that R1 to R5 are independently selected from one or a combination of two of methyl, ethyl, tert-butyl, phenyl, naphthyl, biphenyl, anthracenyl, phenanthryl, pyrene, fluoranthene, pyridyl, pyrrolyl, pyranyl, pyrimidinyl, triazine, pyrazinyl, quinolyl, dibenzofuranyl, dibenzothiophenyl, dibenzocarbazolyl, 9,9-diphenylfluorenyl, 9,9-dimethylfluorenyl, spirofluorenyl, silafluorenyl and amine.

4. The compound according to claim 1, characterized in that Adjacent R1 and R5, and / or adjacent R3 and R4, form a substituted or unsubstituted ring.

5. The compound according to claim 1, characterized in that Has any of the following structures:

6. An organic electroluminescent device comprising a fluorescent material, characterized in that: The fluorescent light-emitting material comprises the compound according to any one of claims 1 to 5.

7. An organic electroluminescent device, comprising a light-emitting layer material, characterized in that: The light-emitting layer material comprises the compound according to any one of claims 1 to 5.

8. Use of the compound according to any one of claims 1 to 5 in an organic electroluminescent device.

9. Use of the compound according to any one of claims 1 to 5 in an organic electroluminescent device.

10. The use according to any one of claims 8 or 9, characterized in that: The compound has at least one function of reducing driving voltage, improving external quantum efficiency, and improving color purity.

Images