Carbonyl fused boron heterocyclic compound as well as preparation method and application thereof

Abstract

The invention discloses a carbonyl condensed boron heterocyclic compound as well as a preparation method and application thereof. The structural general formula of the carbonyl fused boron heterocyclic compound is # imgabs0 #, Ar1, Ar2, Ar3, Ar4 and Ar5 are respectively and independently selected from one of C6-C60 aromatic rings and C3-C60 heteroaromatic rings, X1, X2, X3 and X4 are respectively and independently selected from one of alkyl nitrogen, aryl nitrogen, nitrogen, oxygen, sulfur, selenium, carbonyl, sulfoxide, sulfuryl and phosphorus oxygen, and dotted lines are bonded or not bonded. The carbonyl condensed boron heterocyclic compound provided by the invention is a long-wavelength luminescence MR-TADF material with a large anti-intersystem crossing rate, and a device prepared from the material has excellent luminescence performance and good stability, and is suitable for large-scale application in the field of electroluminescence.

Description

Technical Field

[0001] The invention relates to the technical field of electroluminescence, and in particular to a carbonyl-fused boron heterocyclic compound and a preparation method and application thereof. Background Art

[0002] Organic Light-Emitting Diode (OLED) is a current-type organic light-emitting device that emits light through the injection and recombination of carriers. Studies have shown that organic electroluminescent devices will produce 25% singlet excitons and 75% triplet excitons under the condition of electrical excitation, and there is a direct correlation between the luminous efficiency of the device and the exciton utilization rate of the device. At present, the luminescent materials used for OLED are mainly divided into traditional fluorescent materials, phosphorescent materials, hot exciton materials, thermally activated delayed fluorescence (TADF) materials and multiple resonance thermally activated delayed fluorescence (MR-TADF) materials. Traditional fluorescent materials can only utilize 25% of singlet excitons, and the exciton utilization rate is relatively low, so the luminous efficiency of the device is relatively low. Phosphorescent materials have metal-to-ligand charge transfer (MLCT) states, so they can utilize the other 75% of triplet excitons, but because phosphorescent materials need to be composed of precious metals, their prices are very expensive, and commercial applications are greatly limited. TADF materials have a small single-triplet energy level difference. Triplet excitons can cross from the triplet energy level back to the singlet energy level under the action of heat, and then radiate delayed fluorescence. Theoretically, 100% exciton utilization can be achieved. Although this process does not require the participation of precious metals, it is necessary to introduce a donor-acceptor (DA) structure into the molecule to separate the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), thereby narrowing the single-triplet energy level difference. However, the introduction of the DA structure will inevitably lead to the broadening of the material spectrum, which will eventually affect the color purity of the device. MR-TADF materials can localize HOMO and LUMO on heteroatoms in a rigid condensed ring structure on the basis of TADF materials, thereby achieving spectrum narrowing and obtaining high color purity luminescence. At the same time, because the condensed ring structure has a high luminescence quantum efficiency, it can obtain excellent device luminescence efficiency. In summary, MR-TADF materials have the best application prospects.

[0003] However, existing MR-TADF materials generally have a serious concentration quenching problem due to the slow intersystem crossing rate, which directly affects the luminescence performance and stability of the device. The manufactured devices are still difficult to fully meet the growing requirements of practical applications. In addition, there is currently a lack of MR-TADF materials that emit light at long wavelengths.

[0004] Therefore, it is of great significance to develop a long-wavelength luminescent MR-TADF material with a large antisystem crossing rate, excellent luminescence performance and good stability of the manufactured device. Summary of the invention

[0005] The object of the present invention is to provide a carbonyl-fused boron heterocyclic compound and a preparation method and application thereof.

[0006] The technical solution adopted by the present invention is:

[0007] A carbonyl-fused boron heterocyclic compound, the general structural formula of which is shown in Formula 1-1 or Formula 1-2:

[0008] Formula 1-1: Formula 1-2: wherein Ar1, Ar2, Ar3, Ar4 and Ar5 are each independently selected from C6 to C 60 Aromatic ring, C3~C 60 One of the heteroaromatic rings, X1, X2, X3 and X4 are each independently selected from one of alkyl nitrogen, aryl nitrogen, nitrogen, oxygen, sulfur, selenium, carbonyl, sulfoxide, sulfone and phosphorus oxygen, and the dotted line indicates bonding or non-bonding.

[0009] Preferably, the general structural formula of the carbonyl-fused boron heterocyclic compound is as shown in Formula 2-1 or Formula 2-2:

[0010] Formula 2-1: Formula 2-2: wherein Ar1, Ar2, Ar3, Ar4 and Ar5 are each independently selected from C6 to C 60 Aromatic ring, C3~C 60 One of the heteroaromatic rings, X1, X2, X3 and X4 are each independently selected from one of nitrogen, oxygen, sulfur, selenium, carbonyl, sulfoxide, sulfone and phosphorus oxygen, Y1, Y2, Y3 and Y4 are each independently selected from one of alkyl nitrogen, aryl nitrogen, nitrogen, oxygen, sulfur, selenium, carbonyl, sulfoxide, sulfone and phosphorus oxygen, and the dotted line indicates bonding or non-bonding.

[0011] Further preferably, the general structural formula of the carbonyl-fused boron heterocyclic compound is as shown in Formula 3-1 or Formula 3-2:

[0012] Formula 3-1: Formula 3-2: wherein Ar1, Ar2, Ar3, Ar4, Ar5, Ar6 and Ar7 are each independently selected from C6 to C 60 Aromatic ring, C3~C 60 One of the heteroaromatic rings, X1, X2, X3 and X4 are each independently selected from one of nitrogen, oxygen, sulfur, selenium, carbonyl, sulfoxide, sulfone and phosphorus oxygen, Y1, Y2, Y3, Y4, Y5 and Y6 are each independently selected from one of nitrogen, oxygen, sulfur, selenium, carbonyl, sulfoxide, sulfone and phosphorus oxygen, and the dotted line indicates bonding or non-bonding.

[0013] Still more preferably, the carbonyl-fused boron heterocyclic compound is any one of the compounds represented by the following structural formulas:

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024] More preferably, the carbonyl-fused boron heterocyclic compound is any one of the compounds represented by the following structural formulas:

[0025] Preferably, Ar1, Ar2, Ar3, Ar4, Ar5, Ar6 and Ar7 are each independently selected from one of the following structures:

[0026]

[0027]

[0028]

[0029] A method for preparing the carbonyl-fused boron heterocyclic compound as described above comprises the following steps: firstly synthesizing an intermediate INT-1A / 2A, then reacting INT-1A / 2A with boron tribromide to obtain an intermediate INT-1B / 2B, and then reacting INT-1B / 2B with 2,3-dichloro-5,6-dicyano-p-benzoquinone to obtain target compounds C1 and C2;

[0030] The specific synthesis path is as follows:

[0031]

[0032] Preferably, the molar ratio of INT-1A / 2A to boron tribromide is 1:2-6.

[0033] Preferably, the molar ratio of INT-1B / 2B and 2,3-dichloro-5,6-dicyano-p-benzoquinone is 1:4-8.

[0034] An organic electroluminescent device, the light-emitting layer of which contains the carbonyl-fused boron heterocyclic compound (the carbonyl-fused boron heterocyclic compound is used as a guest doping material in the light-emitting layer in combination with other host materials).

[0035] Preferably, the composition of the organic electroluminescent device includes an anode layer, an organic functional layer and a cathode layer arranged in sequence, and the composition of the organic functional layer includes a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer and an electron injection layer arranged in sequence.

[0036] Preferably, the anode layer is composed of at least one of indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), and zinc oxide (ZnO).

[0037] Preferably, the hole injection layer is composed of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HATCN).

[0038] Preferably, the hole transport layer is composed of at least one of 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline] (TAPC) and tris(4-carbazolyl-9-ylphenyl)amine (TCTA).

[0039] Preferably, the electron blocking layer is composed of 9-(2-(9-phenyl-9H-carbazole-3-yl)phenyl)-9H-3,9'-biscarbazole (PhCzBCz).

[0040] Preferably, the hole blocking layer is composed of 2,8-bis(diphenylphosphoryl)dibenzo[B,D]furan (PPF).

[0041] Preferably, the electron transport layer is composed of 1,3,5-tris(3-pyridyl-3-phenyl)benzene (TmPyPB).

[0042] Preferably, the electron injection layer is composed of lithium fluoride (LiF).

[0043] Preferably, the preparation method of each layer in the organic functional layer is one of vacuum thermal evaporation method, spin coating method and inkjet printing method.

[0044] Preferably, the cathode layer is composed of at least one of magnesium (Mg), silver (Ag), aluminum (Al), lithium (Li), calcium (Ca), and indium (In).

[0045] A display device comprises the organic electroluminescent device.

[0046] An electronic device comprises the above display device.

[0047] Preferably, the electronic device includes, but is not limited to, flat panel displays, monitors, medical monitors, televisions, billboards, lights for indoor or outdoor lighting and / or signaling, heads-up displays, fully or partially transparent displays, flexible displays, smart phones, tablet computers, tablet phones, wearable devices, smart watches, laptops, digital cameras, camcorders, viewfinders, microdisplays, 3D displays, vehicle displays and taillights.

[0048] The beneficial effects of the present invention are as follows: the carbonyl-fused boron heterocyclic compound of the present invention is a long-wavelength luminescent MR-TADF material with a large reverse intersystem crossing rate, and the device made thereof has excellent luminescent performance and good stability, and is suitable for large-scale application in the field of electroluminescence.

[0049] Specifically:

[0050] 1) The present invention introduces a second acceptor carbonyl group into the boron-containing fused ring structure, which can achieve narrow-band emission while changing the electron cloud distribution of the benzene ring, effectively regulating the excited state characteristics of the molecule, and modulating the peak wavelength of the luminescence spectrum, thereby obtaining a new organic light-emitting material with high luminescence quantum efficiency, short delayed life and narrow spectral half-peak width;

[0051] 2) The present invention introduces a second acceptor carbonyl group into the boron-containing fused ring structure. The carbonyl group can participate in multiple resonances. The constructed new multiple resonance mother core can further reduce the single-triplet energy level difference of the material, promote the anti-intersystem crossing process, and effectively improve the efficiency roll-off problem of boron-nitrogen materials in organic electroluminescent devices;

[0052] 3) The present invention introduces a second acceptor carbonyl group into the boron-containing fused ring structure. The introduction of the carbonyl group can increase the conjugation degree of the multi-resonance mother nucleus, thereby achieving long-wavelength luminescence. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is the hydrogen nuclear magnetic resonance spectrum of compound C1-57 in Example 1.

[0054] Figure 2 This is the carbon NMR spectrum of compound C1-57 in Example 1.

[0055] Figure 3The current density-voltage-brightness characteristic curves of the organic electroluminescent OLED devices made of the carbonyl-fused boron heterocyclic compounds in Examples 1 to 3.

[0056] Figure 4 The electroluminescence spectra of the organic electroluminescent OLED devices made from the carbonyl-fused boron heterocyclic compounds in Examples 1 to 3 are shown.

[0057] Figure 5 The external quantum efficiency-brightness curves of the organic electroluminescent OLED devices made from the carbonyl-fused boron heterocyclic compounds in Examples 1 to 3. DETAILED DESCRIPTION

[0058] The present invention will be further explained and illustrated below in conjunction with specific embodiments.

[0059] The synthesis route of the carbonyl-fused boron heterocyclic compound of the present invention is exemplified as follows:

[0060] Synthetic route 1:

[0061]

[0062] Synthesis route 2:

[0063]

[0064] Synthetic route 3:

[0065]

[0066] Synthetic route 4:

[0067]

[0068] Synthetic route 5:

[0069]

[0070] Embodiment 1:

[0071] A carbonyl-fused boron heterocyclic compound (Compound C1-57), the preparation method of which is as follows:

[0072] 1) Synthesis of intermediate A:

[0073] 20 g (1.0 eq) of 3,5-dibromotoluene, 15.38 g (2.0 eq) of sodium tert-butoxide, 179.65 mg (1%) of palladium acetate and 464.34 mg (2%) of tri-tert-butylphosphine tetrafluoroborate were added to a dry three-necked flask with a volume of 500 mL in sequence, and the air in the flask was replaced by nitrogen, and the replacement was repeated 3 times. Then 23.80 g (2.2 eq) of trimethylaniline and 300 mL of toluene were added, and the mixture was heated to reflux and reacted overnight. The reaction was monitored by thin layer chromatography (TLC) to be complete, and the mixture was cooled to room temperature, and an appropriate amount of water and dichloromethane were added for extraction. The organic phase was separated, dried over anhydrous magnesium sulfate, concentrated, and subjected to column chromatography to obtain 26.8 g of intermediate A (white solid, yield 93.4%);

[0074] The reactions involved in this step are as follows:

[0075]

[0076] 2) Synthesis of intermediate C1-57B:

[0077] 2.5 g (1.0 eq) of intermediate A, 4.47 g (2.2 eq) of 2-bromothioxanthone, 2.01 g (3.0 eq) of sodium tert-butoxide, 78.27 mg (5%) of palladium acetate and 202.31 mg (10%) of tri-tert-butylphosphine tetrafluoroborate were added to a dry three-necked flask with a volume of 250 mL in sequence, and the air in the flask was replaced by nitrogen, and the replacement was repeated 3 times. Then 120 mL of toluene was added, and the mixture was heated to reflux and reacted overnight. The reaction was monitored by thin layer chromatography (TLC) to be complete, and the mixture was cooled to room temperature, and an appropriate amount of water and dichloromethane were added for extraction. The organic phase was separated, dried over anhydrous magnesium sulfate, concentrated, and subjected to column chromatography to obtain 4.86 g of intermediate C1-57B (yellow solid, yield 89.5%);

[0078] The reactions involved in this step are as follows:

[0079]

[0080] 3) Synthesis of intermediate C1-57C:

[0081] 4.8 g (1.0 eq) of intermediate C1-57B was added to a dry three-necked flask with a volume of 250 mL, and the air in the flask was replaced by nitrogen, and the replacement was repeated 3 times. Then 50 mL of ultra-dry tetrahydrofuran was added, and then 19 mL of a 1 mol / L borane tetrahydrofuran solution was slowly added, and then heated to 70 ° C and refluxed with stirring for 2.5 h, cooled to room temperature, and then 30 mL of methanol was added under ice-water bath conditions to quench the remaining borane, and the solvent was removed by rotary evaporation and column chromatography was performed. The eluent was composed of petroleum ether and dichloromethane in a volume ratio of 5:1 to obtain 4.51 g of intermediate C1-57C (yield was 97.2%);

[0082] The reactions involved in this step are as follows:

[0083]

[0084] 4) Synthesis of intermediate C1-57D:

[0085] 4.5 g (1.0 eq) of intermediate C1-57C was added to a 100 mL dry reaction tube, and the air in the tube was replaced by nitrogen. The replacement was repeated 3 times, and then 30 mL of ultra-dry o-dichlorobenzene was added, and the temperature was lowered to -30°C. Then 2.23 mL (4.0 eq) of boron tribromide was added, and the temperature was raised to 180°C. The reaction was allowed to proceed overnight. The reaction was monitored by thin layer chromatography (TLC) to complete the reaction. The reaction was cooled to room temperature, and methanol was added in an ice-water bath to quench the remaining boron tribromide. The reaction solution was concentrated and subjected to column chromatography to obtain 3.8 g of intermediate C1-57D (yellow solid, yield 84%).

[0086] The reactions involved in this step are as follows:

[0087]

[0088] 5) Synthesis of carbonyl-fused boron heterocyclic compound (Compound C1-57):

[0089] 0.2 g (1.0 eq) of intermediate C1-57D was added to a dry three-necked flask with a volume of 25 mL, and then 5 mL of dichloromethane was added, and then 5 mL of dichloromethane solution containing 360 mg (6.0 eq) of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone was slowly added under ice-water bath conditions, and then the temperature was raised to room temperature for reaction for 3 h. After the solvent was removed by rotary evaporation, column chromatography was performed, and the eluent was composed of petroleum ether and dichloromethane in a volume ratio of 1:1 to obtain 0.13 g of compound C1-57 (red solid, yield 63%);

[0090] The reactions involved in this step are as follows:

[0091]

[0092] The H NMR spectrum of compound C1-57 in this example is as follows Figure 1 As shown, the carbon NMR spectrum is as follows Figure 2 shown.

[0093] Depend on Figure 1 and Figure 2 It can be seen that: this example indeed synthesized a carbonyl-fused boron heterocyclic compound with the expected structure.

[0094] Embodiment 2:

[0095] A carbonyl-fused boron heterocyclic compound (Compound C1-49), the preparation method of which is as follows:

[0096] 1) Synthesis of intermediate C1-49A:

[0097] 20 g (1.0 eq) of 1-chloro-3,5-dibromobenzene, 14.22 g (2.0 eq) of sodium tert-butoxide, 332.18 mg (2%) of palladium acetate and 643.91 mg (3%) of tri-tert-butylphosphine tetrafluoroborate were added to a dry three-necked flask with a volume of 500 mL in sequence, and the air in the flask was replaced with nitrogen, and the replacement was repeated 3 times. Then 20.51 g (2.05 eq) of trimethylaniline and 300 mL of toluene were added, and the mixture was heated to reflux and reacted overnight. The reaction was monitored by thin layer chromatography (TLC) to be complete, and the mixture was cooled to room temperature, and an appropriate amount of water and dichloromethane were added for extraction. The organic phase was separated, dried over anhydrous magnesium sulfate, concentrated, and subjected to column chromatography to obtain 21.7 g of intermediate C1-49A (white solid, yield 77.3%);

[0098] The reactions involved in this step are as follows:

[0099]

[0100] 2) Synthesis of intermediate C1-49B:

[0101] 6.0 g (1.0 eq) of intermediate C1-49A, 10.04 g (2.2 eq) of N-methyl-2-bromoacridone, 4.57 g (3.0 eq) of sodium tert-butoxide, 177.74 mg (5%) of palladium acetate and 459.38 mg (10%) of tri-tert-butylphosphine tetrafluoroborate were added to a dry three-necked flask with a volume of 250 mL in sequence, and the air in the flask was replaced by nitrogen, and the replacement was repeated 3 times. Then 120 mL of toluene was added, and the mixture was heated to reflux and reacted overnight. The reaction was monitored by thin layer chromatography (TLC) to be complete, and the mixture was cooled to room temperature, and an appropriate amount of water and dichloromethane were added for extraction. The organic phase was separated, dried over anhydrous magnesium sulfate, concentrated, and subjected to column chromatography to obtain 6.4 g of intermediate C1-49B (orange solid, yield 50.9%);

[0102] The reactions involved in this step are as follows:

[0103]

[0104] 3) Synthesis of intermediate C1-49C:

[0105] 5.0 g (1.0 eq) of intermediate C1-49B was added to a dry three-necked flask with a volume of 250 mL, and the air in the flask was replaced by nitrogen, and the replacement was repeated 3 times. Then 50 mL of ultra-dry tetrahydrofuran was added, and then 25 mL of a 1 mol / L borane tetrahydrofuran solution was slowly added, and then heated to 70 ° C and refluxed with stirring for 2.5 h, cooled to room temperature, and then 30 mL of methanol was added under ice-water bath conditions to quench the remaining borane, and the solvent was removed by rotary evaporation and column chromatography was performed. The eluent was composed of petroleum ether and dichloromethane in a volume ratio of 5:1, and 4.12 g of intermediate C1-49C (yield was 82.4%) was obtained;

[0106] The reactions involved in this step are as follows:

[0107]

[0108] 4) Synthesis of intermediate C1-49D:

[0109] 4.5 g (1.0 eq) of intermediate C1-49C was added to a 100 mL dry reaction tube, and the air in the tube was replaced by nitrogen. The replacement was repeated 3 times, and then 30 mL of ultra-dry o-dichlorobenzene was added, and the temperature was lowered to -30°C. Then 2.5 mL (4.0 eq) of boron tribromide was added, and the temperature was raised to 180°C. The reaction was allowed to proceed overnight. The reaction was monitored by thin layer chromatography (TLC) to complete the reaction. The reaction was cooled to room temperature, and methanol was added in an ice-water bath to quench the remaining boron tribromide. The reaction solution was concentrated and subjected to column chromatography to obtain 2.1 g of intermediate C1-49D (yellow solid, yield 47%).

[0110] The reactions involved in this step are as follows:

[0111]

[0112] 5) Synthesis of intermediate C1-49E:

[0113] 0.2 g (1.0 eq) of intermediate C1-49D was added to a dry three-necked flask with a volume of 25 mL, and then 5 mL of dichloromethane was added, and then 5 mL of dichloromethane solution containing 420 mg (6.0 eq) of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone was slowly added under ice-water bath conditions, and then the temperature was raised to room temperature for reaction for 3 h. After the solvent was removed by rotary evaporation, column chromatography was performed, and the eluent was composed of petroleum ether and dichloromethane in a volume ratio of 1:2 to obtain 0.11 g of intermediate C1-49E (dark purple solid, yield 54%);

[0114] The reactions involved in this step are as follows:

[0115]

[0116] 6) Synthesis of intermediate C1-49F:

[0117] 1.0 g (1.0 eq) of intermediate C1-49E was added to a dry three-necked flask with a volume of 100 mL, and then 950.9 mg (3 eq) of dipinacol borate, 367.5 mg (3 eq) of potassium acetate, 34.3 mg (0.03 eq) of Pd2(dba)3 and 35.7 mg (0.06 eq) of XPhos were added in sequence, and the air in the tube was replaced by nitrogen, and the replacement was repeated 3 times, and then the temperature was raised to 100 ° C to react overnight, and extracted with dichloromethane and water, and the organic phase was concentrated, and then column chromatography was performed, and the eluent was dichloromethane to obtain 0.6 g of intermediate C1-49F (red solid, yield 61%);

[0118] The reactions involved in this step are as follows:

[0119]

[0120] 7) Synthesis of carbonyl-fused boron heterocyclic compound (Compound C1-49):

[0121] 0.5 g (1.0 eq) of intermediate C1-49F, 0.18 g (1.2 eq) of 2-chloro-4,6-diphenyl-1,3,5-triazine, 0.39 g (5.0 eq) of potassium carbonate and 33 mg (5%) of tetrakistriphenylphosphine palladium were added to a dry two-necked flask with a volume of 100 mL in sequence, and the air in the tube was replaced by nitrogen, and the replacement was repeated 3 times. Then 40 mL of tetrahydrofuran and 20 mL of water were added, and the mixture was heated to reflux and reacted overnight. The reaction was monitored by thin layer chromatography (TLC) to be complete, and the mixture was cooled to room temperature, and an appropriate amount of ethyl acetate was added for extraction, and the organic phase was separated, dried over anhydrous magnesium sulfate, concentrated, and subjected to column chromatography to obtain 0.3 g of compound C1-49 (purple solid, yield 54%);

[0122] The reactions involved in this step are as follows:

[0123]

[0124] After testing (the testing method is the same as that of Example 1), this example indeed synthesized a carbonyl-fused boron heterocyclic compound with the expected structure.

[0125] Embodiment 3:

[0126] A carbonyl-fused boron heterocyclic compound (Compound C1-128), the preparation method of which is as follows:

[0127] 1) Synthesis of intermediate C1-128A:

[0128] 3 g (1 eq) of 3,5-difluoro-tert-butylbenzene, 12.89 g (2.1 eq) of indole selenoxanthone and 17.23 g (3 eq) of cesium carbonate were added to a dry two-necked flask with a volume of 250 mL in sequence, and the air in the flask was replaced by nitrogen, and the replacement was repeated 3 times. Then 70 mL of N,N-dimethylformamide was added, and the mixture was heated to reflux. The reaction was allowed to proceed overnight. The reaction was monitored by thin layer chromatography (TLC) to be complete, and the mixture was cooled to room temperature. An appropriate amount of water was added (a large amount of orange solid was precipitated), and the mixture was filtered. The solid was taken and heated and slurried twice with 50 mL of methanol, cooled to room temperature, filtered, and the solid was taken to obtain 12.5 g of intermediate C1-128A (orange-yellow solid, yield 86%);

[0129] The reactions involved in this step are as follows:

[0130]

[0131] 2) Synthesis of intermediate C1-128B:

[0132] 5.0 g (1.0 eq) of intermediate C1-128A was added to a dry three-necked flask with a volume of 250 mL, and the air in the flask was replaced by nitrogen, and the replacement was repeated 3 times. Then 50 mL of ultra-dry tetrahydrofuran was added, and then 38 mL of a 1 mol / L borane tetrahydrofuran solution was slowly added, and then heated to 70 ° C and refluxed with stirring for 2.5 h, cooled to room temperature, and then 50 mL of methanol was added under ice-water bath conditions to quench the remaining borane, and the solvent was removed by rotary evaporation and column chromatography was performed. The eluent was composed of petroleum ether and dichloromethane in a volume ratio of 5:1 to obtain 4.3 g of intermediate C1-128B (yield was 89%);

[0133] The reactions involved in this step are as follows:

[0134]

[0135] 3) Synthesis of intermediate C1-128C:

[0136] 4.0 g (1.0 eq) of intermediate C1-128B was added to a 100 mL dry reaction tube, and the air in the tube was replaced by nitrogen, and the replacement was repeated 3 times. Then 30 mL of ultra-dry o-dichlorobenzene was added, and the temperature was lowered to -30°C. Then 1.95 mL (4.0 eq) of boron tribromide was added, and the temperature was raised to 180°C. The reaction was allowed to proceed overnight. The reaction was monitored by thin layer chromatography (TLC) to complete the reaction. The reaction was cooled to room temperature, and methanol was added in an ice-water bath to quench the remaining boron tribromide. The reaction solution was concentrated and subjected to column chromatography to obtain 2.6 g of intermediate C1-128C (yellow-green solid, yield 64%).

[0137] The reactions involved in this step are as follows:

[0138]

[0139] 4) Synthesis of carbonyl-fused boron heterocyclic compound (Compound C1-128):

[0140] 0.2 g (1.0 eq) of intermediate C1-128C was added to a dry three-necked flask with a volume of 25 mL, and then 5 mL of dichloromethane was added, and then 5 mL of dichloromethane solution containing 220 mg of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone was slowly added under ice-water bath conditions, and then the temperature was raised to room temperature for reaction for 3 h. After the solvent was removed by rotary evaporation, column chromatography was performed, and the eluent was composed of petroleum ether and dichloromethane in a volume ratio of 1:2 to obtain 0.081 g of compound C1-128 (purple solid, yield 39%);

[0141] The reactions involved in this step are as follows:

[0142]

[0143] After testing (the testing method is the same as that of Example 1), this example indeed synthesized a carbonyl-fused boron heterocyclic compound with the expected structure.

[0144] Embodiment 4:

[0145] A carbonyl-fused boron heterocyclic compound (Compound C1-56), which is exactly the same as Example 1 except that "2-bromothioxanthone" in step 2) is replaced by "2-bromothioxanthone" (equimolar replacement) during preparation.

[0146] After testing (the testing method is the same as that of Example 1), this example indeed synthesized a carbonyl-fused boron heterocyclic compound with the expected structure.

[0147] Embodiment 5:

[0148] A carbonyl-fused boron heterocyclic compound (Compound C1-48), which is exactly the same as Example 2 except that "N-methyl-2-bromoacridone" in step 2) is replaced by "2-bromoselenoxanthone" (equimolar replacement) during preparation.

[0149] After testing (the testing method is the same as that of Example 1), this example indeed synthesized a carbonyl-fused boron heterocyclic compound with the expected structure.

[0150] Embodiment 6:

[0151] A carbonyl-fused boron heterocyclic compound (Compound C2-57), which is exactly the same as Example 1 except that "2-bromothioxanthone" in step 2) is replaced by "4-bromothioxanthone" (equimolar replacement) during preparation.

[0152] After testing (the testing method is the same as that of Example 1), this example indeed synthesized a carbonyl-fused boron heterocyclic compound with the expected structure.

[0153] Embodiment 7:

[0154] A carbonyl-fused boron heterocyclic compound (Compound C1-58), which is exactly the same as Example 1 except that "2-bromothioxanthone" in step 2) is replaced by "2-bromoselenoxanthone" (equimolar replacement) during preparation.

[0155] After testing (the testing method is the same as that of Example 1), this example indeed synthesized a carbonyl-fused boron heterocyclic compound with the expected structure.

[0156] Embodiment 8:

[0157] A carbonyl-fused boron heterocyclic compound (Compound C2-56), which is exactly the same as Example 1 except that "2-bromothioxanthone" in step 2) is replaced by "4-bromothioxanthone" (equimolar replacement) during preparation.

[0158] After testing (the testing method is the same as that of Example 1), this example indeed synthesized a carbonyl-fused boron heterocyclic compound with the expected structure.

[0159] Embodiment 9:

[0160] A carbonyl-fused boron heterocyclic compound (Compound C2-48), which is exactly the same as Example 2 except that "N-methyl-2-bromoacridone" in step 2) is replaced by "4-bromoselenoxanone" (equimolar replacement) during preparation.

[0161] After testing (the testing method is the same as that of Example 1), this example indeed synthesized a carbonyl-fused boron heterocyclic compound with the expected structure.

[0162] Embodiment 10:

[0163] A carbonyl-fused boron heterocyclic compound (Compound C2-58), which is exactly the same as Example 1 except that "2-bromothioxanthone" in step 2) is replaced by "4-bromoselenoxanthone" (equimolar replacement) during preparation.

[0164] After testing (the testing method is the same as that of Example 1), this example indeed synthesized a carbonyl-fused boron heterocyclic compound with the expected structure.

[0165] Performance Test:

[0166] Organic electroluminescent OLED devices 1 to 3 were prepared using the carbonyl-fused boron heterocyclic compounds (light-emitting layer; guest) in Examples 1 to 3.

[0167] The structure of an organic electroluminescent OLED device is as follows:

[0168] ITO / HATCN(5nm) / TAPC(30nm) / TCTA(10nm) / PhCzBCz(10nm) / PhCzBCz:10wt%TPTZ:1wt%Guest(30nm) / PPF(10nm) / TmPyPB(40nm) / LiF(1nm) / Al(120nm).

[0169] The structures of HATCN, TAPC, TCTA, PhCzBCz, PPF, and TmPyPB are shown below:

[0170]

[0171] The preparation process of organic electroluminescent OLED devices is as follows:

[0172] The glass substrate coated with indium tin oxide (ITO) was ultrasonically treated with deionized water, acetone and isopropanol for 30 minutes respectively, and then cleaned with ultraviolet ozone for 15 minutes. The treated ITO glass substrate was placed in the vacuum chamber of the evaporation equipment as the anode layer, evacuated, and then vacuum-evaporated the organic functional layer and the cathode aluminum layer to obtain an organic electroluminescent OLED device.

[0173] The performance test of the organic electroluminescent OLED device is shown in the following table (the current density-voltage-brightness characteristic curve of the organic electroluminescent OLED device is shown in Figure 3 The electroluminescence spectrum is shown in Figure 4 As shown, the external quantum efficiency-brightness curve is as follows Figure 5 shown):

[0174] Table 1 Performance test data of organic electroluminescent OLED devices

[0175]

[0176] From Table 1 and Figures 3 to 5 It can be seen that the organic electroluminescent OLED devices made by using the carbonyl-fused boron heterocyclic compounds in Examples 1 to 3 as guest doping materials in the light-emitting layer can achieve high brightness, red shift of the luminescence peak, and small efficiency roll-off while maintaining a narrow half-peak width, and the organic electroluminescent OLED devices have high stability.

[0177] In addition, through the same test, it was found that the organic electroluminescent OLED devices made by using the carbonyl-fused boron heterocyclic compound in the present invention as the guest doping material in the light-emitting layer can achieve high brightness, red shift of the luminescence peak, and small efficiency roll-off while maintaining a narrow half-width (that is, the organic electroluminescent OLED device has high stability).

[0178] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A carbonyl-fused boron heterocyclic compound, characterized in that: The general structural formula is shown in Formula 1-1 or Formula 1-2: Formula 1-1: Formula 1-2: wherein Ar1, Ar2, Ar3, Ar4 and Ar5 are each independently selected from C6 to C 60 Aromatic ring, C3~C 60 One of the heteroaromatic rings, X1, X2, X3 and X4 are each independently selected from one of alkyl nitrogen, aryl nitrogen, nitrogen, oxygen, sulfur, selenium, carbonyl, sulfoxide, sulfone and phosphorus oxygen, and the dotted line indicates bonding or non-bonding.

2. The carbonyl-fused boron heterocyclic compound according to claim 1, characterized in that: The general structural formula of the carbonyl-fused boron heterocyclic compound is shown in Formula 2-1 or Formula 2-2: Formula 2-1: Formula 2-2: wherein Ar1, Ar2, Ar3, Ar4 and Ar5 are each independently selected from C6 to C 60 Aromatic ring, C3~C 60 One of the heteroaromatic rings, X1, X2, X3 and X4 are each independently selected from one of nitrogen, oxygen, sulfur, selenium, carbonyl, sulfoxide, sulfone and phosphorus oxygen, Y1, Y2, Y3 and Y4 are each independently selected from one of alkyl nitrogen, aryl nitrogen, nitrogen, oxygen, sulfur, selenium, carbonyl, sulfoxide, sulfone and phosphorus oxygen, and the dotted line indicates bonding or non-bonding.

3. The carbonyl-fused boron heterocyclic compound according to claim 2, characterized in that: The general structural formula of the carbonyl-fused boron heterocyclic compound is shown in Formula 3-1 or Formula 3-2: Formula 3-1: Formula 3-2: wherein Ar1, Ar2, Ar3, Ar4, Ar5, Ar6 and Ar7 are each independently selected from C6 to C 60 Aromatic ring, C3~C 60 One of the heteroaromatic rings, X1, X2, X3 and X4 are each independently selected from one of nitrogen, oxygen, sulfur, selenium, carbonyl, sulfoxide, sulfone and phosphorus oxygen, Y1, Y2, Y3, Y4, Y5 and Y6 are each independently selected from one of nitrogen, oxygen, sulfur, selenium, carbonyl, sulfoxide, sulfone and phosphorus oxygen, and the dotted line indicates bonding or non-bonding.

4. The carbonyl-fused boron heterocyclic compound according to claim 3, characterized in that: The Ar1, Ar2, Ar3, Ar4, Ar5, Ar6 and Ar7 are each independently selected from one of the structures shown below:

5. The carbonyl-fused boron heterocyclic compound according to any one of claims 1 to 4, characterized in that: The carbonyl-fused boron heterocyclic compound is any one of the compounds shown in the following structural formulas:

6. A method for preparing a carbonyl-fused boron heterocyclic compound as claimed in claim 1, characterized in that: The following steps are involved: First, the intermediate INT-1A / 2A is synthesized, and then INT-1A / 2A is reacted with boron tribromide to obtain the intermediate INT-1B / 2B, and then INT-1B / 2B is reacted with 2,3-dichloro-5,6-dicyano-p-benzoquinone to obtain the target compounds C1 and C2; The specific synthesis path is as follows:

7. The preparation method according to claim 6, characterized in that: The molar ratio of INT-1A / 2A to boron tribromide is 1:2-6; the molar ratio of INT-1B / 2B to 2,3-dichloro-5,6-dicyano-p-benzoquinone is 1:4-8.

8. An organic electroluminescent device, characterized in that: The light-emitting layer comprises the carbonyl-condensed boron heterocyclic compound according to any one of claims 1 to 5.

9. A display device, characterized in that: An organic electroluminescent device comprising the organic electroluminescent device according to claim 8.

10. An electronic device, characterized in that: A display device comprising the display device according to claim 9.

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