A boroxin compound and application thereof

Abstract

The present application relates to a kind of boroxanthrene compounds and its application, belong to display material technical field, the structural formula of the boroxanthrene compound is;X, Y each independently selected from oxygen, sulfur, nitrogen;Ar1~Ar3 Each independently selected from hydrogen, deuterium, aryl, aralkyl, heteroalkyl, alkyl, perfluoroalkyl or not exist, when X, Y each independently selected from oxygen, sulfur, Ar1 And Ar3 Not exist;When Ar1~Ar3 Each independently selected from aryl, aralkyl, heteroalkyl, alkyl, perfluoroalkyl, hydrogen in it is not deuterated, partial deuterium or full deuterium;R1~R 12 Each independently selected from hydrogen, alkyl, aryl, aralkyl, heteroalkyl, heteroaryl and perfluoroalkyl, hydrogen in it is not deuterated, partial deuterium or full deuterium;The heteroatom in the heteroalkyl, heteroaryl is selected from oxygen, sulfur, nitrogen.The boroxanthrene compound can improve the luminous efficiency and service life of device.

Description

TECHNICAL FIELD

[0001] The application relates to a boroxanthene compound and application thereof, and belongs to the technical field of display materials. BACKGROUND

[0002] The core of OLED becoming one of the mainstream technologies in the current display field lies in its self-luminous characteristic - no need for a backlight module, and the ability to realize pixel-level precise light emission, which not only makes the device lighter and thinner, but also presents a wider color gamut and pure black display effect. The performance breakthrough of OLED largely depends on the upgrading of the light-emitting layer material, and the thermal activated delayed fluorescence (TADF) material is a key driver, which solves many pain points of traditional light-emitting materials, and makes OLED take a new step in efficiency, cost and application scenarios.

[0003] At the beginning, OLED mainly used fluorescent materials as the light-emitting layer, and such materials had a natural defect: limited by the electron spin rule, they could only utilize 25% of the energy (singlet exciton), and the remaining 75% of the energy (triplet exciton) would be wasted in the form of heat, resulting in low light-emitting efficiency of the device and difficulty in meeting the high-brightness display requirement. Later, researchers developed phosphorescent materials, which could utilize triplet excitons by adding iridium, platinum and other noble metal atoms, and theoretically could achieve 100% energy utilization. However, the cost of noble metals is extremely high, and large-scale production not only increases the product price, but also may cause environmental problems, which makes it difficult for phosphorescent materials to be popularized in low-end devices. When traditional materials were in a bottleneck, the emergence of TADF materials broke the deadlock. In 1961, scientists first discovered the TADF phenomenon, but it was not until 2012 that high-efficiency OLED devices based on TADF materials were formally introduced. The core skill of such materials is that they can convert the originally wasted triplet excitons into luminescent singlet excitons through a thermal activation process without the need for noble metals, achieving the same 100% theoretical energy utilization rate, and being flexible in processing and suitable for a wide range of scenarios. Since then, TADF materials have become a research hotspot in the OLED field, promoting the development of OLED from high-end and niche to popularization.

[0004] To make the performance of TADF materials better, researchers will introduce special structural units into the molecular structure, among which boron oxygen heterocyclic ring and fused ring structure are the two most commonly used structures. They can improve the light-emitting effect and service life of TADF materials from different dimensions, and can be called the "performance amplifier" of TADF. Boron oxygen heterocyclic ring is a ring structure composed of boron, oxygen atoms and aromatic ring, which can make the light-emitting more efficient and stable. Its role in TADF materials mainly has three points: first, boron oxygen heterocyclic ring has strong electron-withdrawing property, forms efficient charge transfer (CT) state with donor unit, can accurately control the separation degree of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), reduce the single-triplet energy level difference (ΔE ST ), and promote its efficient performance. Second, it can inhibit the aggregation quenching. Many light-emitting materials are prone to clustering (π-π stacking) when they are formed into films, which leads to reduced or even extinguished light-emitting. This is the aggregation quenching effect. The steric hindrance of boron oxygen heterocyclic ring is large, which can separate the molecules like a "small support" to avoid clustering. Third, it can optimize the charge transport. Boron oxygen heterocyclic ring can improve the electron transport ability of the material, and make the electron and hole transport in the device more balanced. Fused ring is a "large plane" structure formed by connecting multiple aromatic rings through shared edges, such as naphthalene, anthracene and the like. Its advantages in TADF materials mainly lie in two aspects: on the one hand, it can improve the color purity of light-emitting. The conjugated system of the fused ring structure is large and has good planarity, which can limit molecular vibration and rotation, reduce non-radiative transition (energy is wasted in the form of heat), and make the light-emitting spectrum narrower. The narrower the spectrum, the higher the color purity. On the other hand, it can enhance the stability of the material. The rigid structure of the fused ring can improve the thermal stability and chemical stability of the material. Good thermal stability means that the material is not easy to decompose during device processing and long-term use; good chemical stability can reduce the damage of oxygen and water to the material.

[0005] In general, from the development of OLED technology, TADF materials are the key to breaking through the efficiency and cost bottleneck, and the introduction of boron oxygen heterocyclic ring and fused ring structure further amplifies the advantages of TADF materials, making them perform better in terms of efficiency, stability and high color purity. SUMMARY

[0006] The present application provides a boron oxygen heteroanthracene compound and its application, which has high glass transition temperature and molecular stability, high luminous efficiency and service life, and great potential in the application of organic electroluminescent devices.

[0007] The technical scheme for solving the above technical problems is as follows: a boron oxygen heteroanthracene compound, the structural formula of the boron oxygen heteroanthracene compound is as follows:

[0008] General formula I;

[0009] In the general formula I, X and Y are each independently selected from oxygen, sulfur, nitrogen; Ar1, Ar2, and Ar3 are each independently selected from hydrogen, deuterium, aryl, aralkyl, heteroalkyl, alkyl, perfluoroalkyl, or are not present, and when X and Y are each independently selected from oxygen and sulfur, Ar1 and Ar3 are not present.

[0010] When Ar1, Ar2, and Ar3 are each independently selected from aryl, aralkyl, heteroalkyl, alkyl, and perfluoroalkyl, the hydrogen therein is undeuterated, partially deuterated, or fully deuterated.

[0011] R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 , R 11 , R 12 are each independently selected from hydrogen, alkyl, aryl, aralkyl, heteroalkyl, heteroaryl, and perfluoroalkyl, and the hydrogen therein is undeuterated, partially deuterated, or fully deuterated.

[0012] The heteroatom in the heteroalkyl and heteroaryl is selected from oxygen, sulfur, and nitrogen.

[0013] Further, the boron oxepin compound is selected from the following compounds:

[0014] .

[0015] Further, Ar1, Ar2, and Ar3 are each independently selected from one of the following:

[0016] or are not present.

[0017] Further, in the boron oxepin compound, X and Y are each independently selected from oxygen and sulfur, and X and Y are the same; R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 , R 11 , R 12 are each H.

[0018] Further, the boron oxepin compound is selected from the following compounds:

[0019] .

[0020] The application also discloses an application of the boron oxepin compound, and the boron oxepin compound is applied to an organic electroluminescent device.

[0021] Further, the organic electroluminescent device comprises a cathode layer, an anode layer, and an organic layer, and the boron oxepin compound is applied to the organic layer of the organic electroluminescent device.

[0022] Further, the organic layer comprises a light-emitting layer, the boroxanthene compound is applied to the light-emitting layer, and the light-emitting layer is a blue light-emitting layer.

[0023] Further, the boroxanthene compound is applied to the light-emitting layer as a blue host material.

[0024] Further, the boroxanthene compound is used alone or mixed with other materials in the organic electroluminescent device as a TADF material.

[0025] The beneficial effects of the present application are as follows:

[0026] The boroxanthene compound designed in the present application makes full use of the characteristics of boroxanthine ring and fused ring structure, can effectively reduce the singlet-triplet energy level difference (ΔE ST ), inhibit the occurrence of aggregation quenching effect, improve the electron transport ability of the material, make the transmission of electrons and holes in the device more balanced, and improve the thermal stability and chemical stability.

[0027] In summary, the boroxanthene compound designed in the present application not only has a high glass transition temperature and molecular thermal stability, but also has suitable HOMO and LUMO energy levels, high device light-emitting efficiency and service life, so it has great potential in the application of organic electroluminescent devices. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The figure is a schematic diagram of the organic electroluminescent device structure described in the examples.

[0029] In the figure, 1 is a substrate, 2 is an anode, 3 is a hole injection layer, 4 is a hole transport layer, 5 is a light-emitting layer, 6 is a hole blocking layer, 7 is an electron transport layer, 8 is an electron injection layer, and 9 is a cathode. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below. In the following description, a large number of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the scope of the present application, therefore the present application is not limited by the specific examples disclosed below.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application herein are only for the purpose of describing the specific embodiments and are not intended to limit the present application.

[0032] I. Preparation of compounds

[0033] The specific synthesis method of Example Intermediate 4 is shown below:

[0034]

[0035] Preparation of Intermediate 1: Compound 1 (CAS: 2444-89-5) and dichloromethane were weighed according to a mass ratio of 1:10, and then cooled to -30°C. Then, boron tribromide was weighed according to a molar ratio of compound 1 to boron tribromide of 1:2, and slowly added dropwise to the reaction. After the addition was completed, the temperature was controlled at -30°C for 1 h, and then warmed to 20-25°C for 1 h. GC detection showed that there was no remaining raw material, and the reaction purity was 75.5%. After hydrolysis, extraction, and beating, Intermediate 1 was obtained, with a yield of 54.5% and a GC purity of 97.5%.1H NMR (500 MHz, Chloroform-d): 7.60 (d, 2H), 7.31 (dd, 2H), 7.07 (d, 2H). GC-MS detection: the theoretical molecular weight was 327.8, and the actual detection result was 327.0.

[0036] Preparation of Intermediate 2: Intermediate 1 and tetrahydrofuran were weighed according to a mass ratio of 1:10, and then cooled to -80°C. Then, n-butyllithium in n-hexane solution was measured according to a molar ratio of Intermediate 1 to n-butyllithium of 1:1.1, and the n-butyllithium in n-hexane solution was added dropwise at -80°C. After the addition was completed, the reaction was maintained for 1 h. Then, phenylboronic acid (CAS: 98-80-6) was weighed according to a molar ratio of Intermediate 1 to phenylboronic acid of 1:1.1, and slowly added to the reaction solution at -80°C. After the addition was completed, the reaction was maintained for 1 h, and then warmed to 20-25°C for 2 h. HPLC detection showed that the reaction purity was 78.5.0%. After hydrolysis, extraction, and recrystallization, Intermediate 2 was obtained, with a yield of 62.5% and an HPLC purity of 98.5. 1 H NMR (500 MHz, Chloroform-d): 7.74 (m, 2H), 7.49 (d, 2H), 7.40 (m, 6H), 7.04 (d, 1H). LC-MS: the theoretical molecular weight was 325, and the actual detection result was 325.0.

[0037] ​Preparation of Intermediate 3: Intermediate 2 and Compound 2 (CAS: 1013-88-3) were weighed at a molar ratio of 1.0:2.2. Palladium acetate and S-phos (CAS: 657408-07-6) were added as catalysts, with a molar ratio of catalyst to intermediate 2 of 0.01:1.0. Xylene was used as the solvent, with a solvent mass 10.0 times that of intermediate 2. The reaction system was heated to 130℃ and maintained at this temperature for 8 hours. HPLC analysis showed that 0.45% of the raw material remained, and the product purity was 88.5%. Intermediate 3 was obtained by washing with water, desolventizing, acidifying, pulping, alkalizing, washing with water again, column chromatography, concentration, and pulping, with an HPLC purity of 99% and a yield of 65.5%. 1 ¹H NMR (500 MHz, Chloroform-d): 7.75–7.68 (m, 2H), 7.40–7.33 (m, 3H), 6.91–6.84 (m, 4H), 6.74 (d, 2H), 5.28 (d, 2H), 5.16 (d, 2H). HPLC-MS: Theoretical molecular weight is 286.1, actual measured molecular weight is 286.0.

[0038] Preparation of intermediate 4: Intermediate 3 and compound 3 (CAS: 694-80-4) were weighed in a molar ratio of 1.0:1.05. Palladium acetate and S-phos (CAS: 657408-07-6) were added as catalysts, with a catalyst-to-intermediate 3 molar ratio of 0.01:1.0. Xylene was used as the solvent, with a solvent mass 10.0 times that of intermediate 3. The reaction system was heated to 125℃ and maintained at this temperature for 10 h. HPLC analysis showed that 0.22% of the raw material remained, and the product purity was 87.5%. Intermediate 4 was obtained by washing with water, column chromatography, concentration, and pulping, with an HPLC purity of 99% and a yield of 78.1%. 1 ¹H NMR (500 MHz, Chloroform-d): 7.74–7.67 (m, 2H), 7.39–7.30 (m, 5H), 7.23–7.17 (m, 4H), 7.17–7.05 (m, 4H), 7.07–7.02 (m, 4H), 6.99 (d, 2H). HPLC-MS: Theoretical molecular weight is 507.2, actual measured molecular weight is 507.0.

[0039] Example 1:

[0040] A boron-oxoanthracene-based TADF material, the structural formula of compound A is as follows:

[0041] ;

[0042] The specific synthetic route for compound A is as follows:

[0043] ;

[0044] Preparation of compound A-1 : intermediate 4 and compound 4 (CAS: 108-86-1) were weighed according to the molar ratio of 1.0:1.0, catalyst palladium acetate and S-phos (CAS: 657408-07-6) were added, the molar ratio of catalyst to intermediate 4 was 0.01:1.0, the solvent was xylene, the mass of solvent was 10.0 times of intermediate 4, the reaction system was heated to 125°C, and the reaction was kept for 8h. HPLC detection showed that the remaining raw material was 0.34%, and the product purity was 90.5%. Compound A-1 was obtained by water washing, column chromatography, concentration and beating, and the HPLC purity was 99% with a yield of 80.5%.

[0045] 1 H NMR (500 MHz, Chloroform-d) : 8.13-8.06 (m, 2H), 7.74-7.67 (m, 2H), 7.65-7.58 (m, 2H), 7.54-7.46 (m, 4H), 7.37-7.25 (m, 17H). HPLC-MS: the theoretical molecular weight was 586.5, and the actual detection result was 586.0.

[0046] Preparation of compound A: intermediate A-1 and potassium carbonate (CAS: 584-08-7) were weighed according to the molar ratio of 1.0:2.0, catalyst palladium acetate and tri-tert-butylphosphonium tetrafluoroborate (CAS: 131274-22-1) were added, the molar ratio of palladium acetate and tri-tert-butylphosphonium tetrafluoroborate to intermediate A-1 was 0.05:0.1:1.0, the solvent was N,N-dimethylacetamide, the mass of solvent was 10.0 times of intermediate A-1, the reaction system was heated to 150°C, and the reaction was kept for 10h. HPLC detection showed that the remaining raw material was 0.85%, and the product purity was 95.0%. Compound A was obtained by extraction, water washing, column chromatography, concentration and beating, and the HPLC purity was 98% with a yield of 65.5%.

[0047] 1 H NMR (500 MHz, Chloroform-d) : 8.13-8.06 (m, 2H), 7.74-7.67 (m, 2H), 7.65-7.58 (m, 2H), 7.54-7.46 (m, 4H), 7.37-7.25 (m, 17H). HPLC-MS: the theoretical molecular weight was 586.5, and the actual detection result was 586.0.

[0048] Example 2:

[0049] A boroxin TADF material, compound B has the structural formula:

[0050] ;

[0051] A specific synthesis route of compound B is as follows:

[0052] ;

[0053] Preparation of compound B-1: intermediate 4 and compound 5 (CAS: 4165-57-5) were weighed according to a molar ratio of 1.0:1.0, a catalyst, palladium acetate, and S-phos (CAS: 657408-07-6) were added, the molar ratio of the catalyst to intermediate 4 was 0.01:1.0, the solvent was xylene, the mass of the solvent was 10.0 times that of intermediate 4, the reaction system was heated to 125°C, and the reaction was kept for 7 h. HPLC detection showed that the remaining raw material was 0.45%, and the product purity was 91.5%. Compound B-1 was obtained by water washing, column chromatography, concentration, and beating, and the HPLC purity was 99%, and the yield was 78.5%.

[0054] 1 H NMR (500 MHz, Chloroform-d): 7.72 (d, 2H), 7.33 (d, 3H), 7.24-7.16 (m, 6H), 7.15 (d, 2H), 7.11-7.01 (m, 4H), 6.97 (d, 2H). HPLC-MS: The theoretical molecular weight is 669.4, and the actual detection result is 669.0.

[0055] Preparation of compound B: intermediate B-1 and potassium carbonate (CAS: 584-08-7) were weighed according to a molar ratio of 1.0:2.0, a catalyst, palladium acetate, and tri-tert-butylphosphonium tetrafluoroborate (CAS: 131274-22-1) were added, the molar ratio of palladium acetate and tri-tert-butylphosphonium tetrafluoroborate to intermediate B-1 was 0.05:0.1:1.0, the solvent was N,N-dimethylacetamide, the mass of the solvent was 10.0 times that of intermediate B-1, the reaction system was heated to 150°C, and the reaction was kept for 8 h. HPLC detection showed that the remaining raw material was 0.95%, and the product purity was 93.0%. Compound B was obtained by extraction, water washing, column chromatography, concentration, and beating, and the HPLC purity was 98%, and the yield was 60.5%.

[0056] 1H NMR (500 MHz, Chloroform-d): 8.10 (d, 2H), 7.81 (s, 2H), 7.75-7.68 (m, 2H), 7.63 (d, 2H), 7.39 (s, 2H), 7.36-7.28 (m, 5H), 7.26 (d, 2H). HPLC-MS: Theoretical molecular weight is 596.5, actual detection result is 596.0.

[0057] Example 3:

[0058] A boroxin TADF material, the structural formula of compound C:

[0059] ;

[0060] The specific synthesis route of compound C is:

[0061] ;

[0062] Preparation of compound C-1: intermediate 4 and compound 6 (CAS: 90-11-9) were weighed according to a molar ratio of 1.0:1.0, a catalyst of palladium acetate and S-phos (CAS: 657408-07-6) was added, the molar ratio of catalyst to intermediate 4 was 0.01:1.0, the solvent was xylene, the mass of solvent was 10.0 times that of intermediate 4, the reaction system was heated to 125℃, and the reaction was kept for 9h. HPLC detection showed that the remaining raw material was 0.15%, and the product purity was 94.5%. After washing with water, column, concentration, and beating, compound C-1 was obtained, with an HPLC purity of 98%, and a yield of 75.5%.

[0063] 1 H NMR (500 MHz, Chloroform-d): 7.90 (d, 2H), 7.79 (d, 4H), 7.74-7.67 (m, 2H), 7.55 (t, 2H), 7.52-7.42 (m, 4H), 7.36-7.31 (m, 3H), 7.29-7.20 (m, 4H), 7.20-7.13 (m, 4H), 7.11- 6.98 (m, 6H), 6.96 (d, 2H). HPLC-MS: Theoretical molecular weight is 759.5, actual detection result is 759.0.

[0064] Preparation of Compound C: Intermediate C-1 and potassium carbonate (CAS: 584-08-7) were weighed in a molar ratio of 1.0:2.0. Palladium acetate and tri-tert-butylphosphine tetrafluoroborate (CAS: 131274-22-1) were added as catalysts. The molar ratio of palladium acetate to tri-tert-butylphosphine tetrafluoroborate to intermediate C-1 was 0.05:0.1:1.0. N,N-dimethylacetamide was used as the solvent, with a solvent mass 10.0 times that of intermediate C-1. The reaction system was heated to 150℃ and maintained at this temperature for 10 h. HPLC analysis showed that 0.75% of the raw material remained, and the product purity was 95.0%. Compound C was obtained by extraction, washing with water, column chromatography, concentration, and pulping, with an HPLC purity of 99% and a yield of 65.5%.

[0065] 1 ¹H NMR (500 MHz, Chloroform-d): 8.16–8.09 (m, 2H), 7.78 (d, 2H), 7.74 (t, 4H), 7.68 (d, 2H), 7.63–7.56 (m, 2H), 7.50 (t, 4H), 7.46 (d, 2H), 7.38–7.31 (m, 9H), 7.31–7.23 (m, 4H). HPLC-MS: Theoretical molecular weight is 686.6, actual detected molecular weight is 686.0.

[0066] Example 4:

[0067] A boron-oxoanthracene-based TADF material, the structural formula of its compound D:

[0068] ;

[0069] The specific synthetic route for compound D is as follows:

[0070] ;

[0071] Preparation of compound D-1: Intermediate 4 and compound 7 (CAS: 80984-79-8) were weighed in a molar ratio of 1.0:1.0. Palladium acetate and S-phos (CAS: 657408-07-6) were added as catalysts, with a molar ratio of catalyst to intermediate 4 of 0.01:1.0. Xylene was used as the solvent, with a solvent mass 10.0 times that of intermediate 4. The reaction system was heated to 125℃ and maintained at this temperature for 10 h. HPLC analysis showed that 0.35% of the starting material remained, and the product purity was 92.5%. Compound D-1 was obtained by washing with water, column chromatography, concentration, and pulping, with an HPLC purity of 99% and a yield of 80.5%.

[0072] 1¹H NMR (500 MHz, Chloroform-d): 8.60–8.52 (m, 8H), 7.74–7.67 (m, 2H), 7.50–7.41 (m, 12H), 7.38–7.28 (m, 7H), 7.21 (d, 2H), 7.13–7.05 (m, 4H), 7.03 (t, 2H), 6.98 (d, 2H). HPLC-MS: Theoretical molecular weight is 969.7, actual detected molecular weight is 969.0.

[0073] Preparation of Compound D: Intermediate D-1 and potassium carbonate (CAS: 584-08-7) were weighed in a molar ratio of 1.0:2.0. Palladium acetate and tri-tert-butylphosphine tetrafluoroborate (CAS: 131274-22-1) were added as catalysts. The molar ratio of palladium acetate to tri-tert-butylphosphine tetrafluoroborate to intermediate D-1 was 0.05:0.1:1.0. N,N-dimethylacetamide was used as the solvent, and its mass was 10.0 times that of intermediate D-1. The reaction system was heated to 150℃ and maintained at this temperature for 12 h. HPLC analysis showed that 0.65% of the raw material remained, and the product purity was 97.0%. Compound D was obtained by extraction, washing with water, column chromatography, concentration, and pulping, with an HPLC purity of 99% and a yield of 70.5%.

[0074] 1 ¹H NMR (500 MHz, Chloroform-d): 8.60–8.52 (m, 8H), 8.26 (d, 2H), 7.74–7.68 (m, 2H), 7.50–7.41 (m, 14H), 7.40–7.29 (m, 7H), 7.24 (t, 2H), 7.20 (s, 2H). HPLC-MS: Theoretical molecular weight is 896.8, actual measured molecular weight is 896.0.

[0075] Example 5:

[0076] A boron-oxoanthracene-based TADF material, the structural formula of its compound E:

[0077] ;

[0078] The specific synthetic route for compound E is as follows:

[0079] ;

[0080] Preparation of compound E-1 : intermediate 4 and compound 8 (CAS: 86-76-0) were weighed according to a molar ratio of 1.0:1.0, a catalyst of palladium acetate and S-phos (CAS: 657408-07-6) was added, the molar ratio of the catalyst to intermediate 4 was 0.01:1.0, the solvent was xylene, the mass of the solvent was 10.0 times that of intermediate 4, the reaction system was heated to 125°C, and reaction was kept for 9 h. HPLC detection showed that the raw material was left in an amount of 0.75%, and the product purity was 95.4%. Compound E-1 was obtained by water washing, column passing, concentration, and slurry making, and the HPLC purity was 99%, and the yield was 78.5%.

[0081] 1 H NMR (500 MHz, Chloroform-d): 8.01 (d, 2H), 7.81 (d, 2H), 7.74-7.67 (m, 2H), 7.54 (d, 2H), 7.47 (t, 2H), 7.42-7.30 (m, 7H), 7.25 (d, 2H), 7.21-7.06 (m, 10H), 7.02 (d, 2H), 6.95 (d, 2H). HPLC-MS: the theoretical molecular weight was 806.7, and the actual detection result was 806.0.

[0082] Preparation of compound E: intermediate E-1 and potassium carbonate (CAS: 584-08-7) were weighed according to a molar ratio of 1.0:2.0, a catalyst of palladium acetate and tri-tert-butylphosphonium tetrafluoroborate (CAS: 131274-22-1) was added, the molar ratio of palladium acetate and tri-tert-butylphosphonium tetrafluoroborate to intermediate E-1 was 0.05:0.1:1.0, the solvent was N,N-dimethylacetamide, the mass of the solvent was 10.0 times that of intermediate E-1, the reaction system was heated to 150°C, and reaction was kept for 10 h. HPLC detection showed that the raw material was left in an amount of 0.45%, and the product purity was 96.0%. Compound E was obtained by extraction, water washing, column passing, concentration, and slurry making, and the HPLC purity was 99%, and the yield was 72.5%.

[0083] 1H NMR (500 MHz, Chloroform-d) δ 8.14-8.08 (m, 2H), 8.02 (d, 2H), 7.88 (d, 2H), 7.74-7.69 (m, 2H), 7.65-7.58 (m, 2H), 7.54 (d, 2H), 7.51-7.43 (m, 4H), 7.38 (d, 4H), 7.35-7.29 (m, 7H), 7.29-7.21 (m, 4H). HPLC-MS: Theoretical molecular weight is 839.6, actual detection result is 839.0.

[0084] The TADF material prepared based on the boron xanthene compound can be any one of the following structures:

[0085] .

[0086] The mass spectrometry data of the compound is shown in the following Table 1.

[0087] Table 1 Mass spectrometry data of the compound

[0088]

[0089] II. Device application example

[0090] The OLED light-emitting device is a complex multilayer structure, Figure 1 is a schematic diagram of the structure of an organic electroluminescent device, but is not the only application structure. Generally, a layer of HIT (hole injection layer 3) is plated on a transparent conductive glass or indium-tin oxide ITO, and then a layer of HTL (hole transport layer 4), a layer of EML (light-emitting layer 5), a layer of HBL (hole blocking layer 6), a layer of ETL (electron transport layer 7), and a layer of EIL (electron injection layer 8) are sequentially plated, and finally a layer of metal is added as a conductive cathode 9 and a sealing ring. The boron xanthene compound described in the present application is an excellent TADF material, which can be applied to one or more layers of host material in the light-emitting layer 5. As an example, the material prepared by the boron xanthene compound in the light-emitting layer 5 is studied for device performance.

[0091] Device application example 1:

[0092] An electroluminescent device prepared from a TADF material, the preparation steps of which mainly include: a) ITO substrate anode: the ITO anode 2 on the transparent substrate 1 is first cleaned with distilled water for ten minutes, then cleaned with isopropyl alcohol and acetone respectively for fifteen minutes, and finally treated in a plasma cleaner for ten minutes; b) hole injection layer 3: the hole injection layer 3 material m-MTDATA is evaporated on the ITO anode 2 by vacuum evaporation, with a thickness of 30 nm; c) hole transport layer 4: the hole transport material TTB is evaporated on the m-MTDATA by vacuum evaporation, with a thickness of 50 nm; d) light-emitting layer 5: the light-emitting layer 5 is evaporated on the TTB, using CBP as the first host, using the compound A in the embodiment as the second host material, and using CzTPA as the dopant material, with a mass ratio of CBP, compound A and CzTPA being 67:28:5, and a thickness of 50 nm; e) hole blocking layer 6: the hole blocking material mCBP is evaporated on the host light-emitting material by vacuum evaporation, with a thickness of 10 nm; f) electron transport layer 7: the electron transport material TPBI is evaporated on the host hole blocking material by vacuum evaporation, with a thickness of 50 nm; g) electron injection layer 8: lithium fluoride is evaporated on the TPBI by vacuum evaporation as the electron injection layer, with a thickness of 3 nm; h) conductive cathode: the cathode 9 is evaporated on the TPBI by vacuum evaporation, with a thickness of 150 nm, to form an organic electroluminescent device.

[0093] Device application example 2:

[0094] The difference between this embodiment and device application example 1 is that the host material of the light-emitting layer of the organic electroluminescent device is the compound B of the present application.

[0095] Device application example 3:

[0096] The difference between this embodiment and device application example 1 is that the host material of the light-emitting layer of the organic electroluminescent device is the compound C of the present application.

[0097] Device application example 4:

[0098] The difference between this embodiment and device application example 1 is that the host material of the light-emitting layer of the organic electroluminescent device is the compound D of the present application.

[0099] Device application example 5:

[0100] The difference between this embodiment and device application example 1 is that the host material of the light-emitting layer of the organic electroluminescent device is the compound E of the present application.

[0101] Device comparison example 1:

[0102] The difference between the comparative example and the device application example 1 is that the light-emitting layer host material of the organic electroluminescence device is compound R1, and the structural formula of compound R1 is as follows:

[0103] .

[0104] Device comparative example 2:

[0105] The difference between the comparative example and the device application example 1 is that the light-emitting layer host material of the organic electroluminescence device is compound R2, and the structural formula of compound R2 is as follows:

[0106] .

[0107] The boroxanthene compound described in the application is an excellent TADF material, which can be applied to one or more layers of the host material in the light-emitting layer. The energy level, ΔEst, transient lifetime, PLQY and spectrum of the compound prepared in the above examples of the application are tested, and the data are shown in Table 2.

[0108] Table 2 Performance test of compound

[0109]

[0110] Note: The triplet energy level T1 is tested by Horiba Fluorolog-3 series fluorescence spectrometer, and the test conditions of the material are 2*10 -5 mol / L toluene solution; the highest occupied molecular orbital HOMO energy level is tested by ionization energy test system (IPS-3), and the test is in an atmospheric environment; S1 is tested by Horiba Fluorolog-3 series fluorescence spectrometer, and the test conditions of the material are 2*10 -5 mol / L toluene solution, ΔEst=S1-T1; PLQY and transient lifetime are tested by Horiba Fluorolog-3 series fluorescence spectrometer; the spectrum change is obtained by subtracting the light-emitting peak of the pure film from the light-emitting peak of the blending film doped with 5% CBP, and the test is tested by Horiba Fluorolog-3 series fluorescence spectrometer.

[0111] From the above table data, it can be seen that the compound in the embodiment of the application has suitable energy level and suitable triplet energy, which can be applied to the light-emitting layer of the OLED device as the host, and the compound has high thermal stability, and when it is used as the light-emitting layer material in the application of the OLED device, it has high efficiency and long service life.

[0112] The device performance of device application examples 1-5 and comparative examples 1-2 is tested, and the following organic electroluminescence device performance test data is obtained, and the results are shown in Table 3.

[0113] Table 3 Organic electroluminescent device performance test data

[0114]

[0115] Note: The voltage, current efficiency and color coordinates were tested under a current density of 10 mA / cm 2 The device brightness decay time to 95% was measured using an IVL (current-voltage-luminance) test system (Suzhou Fudashan Scientific Instrument Co., Ltd.) and a lifetime measuring device of McScience Co. under a reference gray scale of 5000 nits.

[0116] As can be seen from the device data results of Table 3, compared with the device comparative example, the device prepared from the material of the present application has advantages in both device efficiency and device lifetime. At the same time, the voltage of the device prepared from the material of the present application is reduced compared with the known material OLED device.

[0117] The TADF material prepared from the boroxanthrene compound described in the present application has high glass transition temperature and molecular thermal stability, and has suitable HOMO and LUMO energy levels, which can improve the luminous efficiency and service life of the device, and has great potential in the application of organic electroluminescent devices.

[0118] The technical features of the above-described embodiments can be combined arbitrarily, and in order to make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present disclosure.

[0119] The above-described embodiments only express several embodiments of the present application, which are described in a more specific and detailed manner, but should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of variations and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present patent should be subject to the appended claims.

Claims

1. A boronoxanthracene compound, characterized in that, The structural formula of the borooxane compounds is as follows: General Formula I: General Formula I; In general formula I, both X and Y are nitrogen; R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 Each is independently selected from hydrogen, alkyl, aryl, aralkyl, heteroalkyl, heteroaryl, and perfluoroalkyl, wherein the hydrogen is undeuterated, partially deuterated, or fully deuterated; The heteroatoms in the heteroalkyl and heteroaryl groups are selected from oxygen, sulfur, and nitrogen; Ar1, Ar2, and Ar3 are each independently selected from: One of them.

2. The boronoxanthracene compound according to claim 1, characterized in that, The borooxane compounds are selected from the following compounds: 。 3. The boronoxanthracene compound according to claim 1, characterized in that, In the boronoxanthracene compounds, R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 All are H.

4. A boronoxanthracene compound, characterized in that, The borooxane compounds are selected from the following compounds: 。 5. An application of a boronoxanthracene compound according to any one of claims 1-4, characterized in that, The boronoxanthracene compounds are used in organic electroluminescent devices.

6. The application of the boronoxanthracene compound according to claim 5, characterized in that, The organic electroluminescent device includes a cathode layer, an anode layer, and an organic layer, wherein the boronoxanthracene compound is applied to the organic layer of the organic electroluminescent device.

7. The application of the boronoxanthracene compound according to claim 6, characterized in that, The organic layer includes a light-emitting layer, the boronoxanthracene compound is applied to the light-emitting layer, and the light-emitting layer is a blue light-emitting layer.

8. The application of the boronoxanthracene compound according to claim 7, characterized in that, The boronoxanthracene compound is used as the blue host material in the luminescent layer.

9. The application of the boronoxanthracene compound according to claim 5, characterized in that, The boronoxanthracene compounds are used alone or in combination with other materials as TADF materials in the organic electroluminescent devices.

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