Condensed ring compound containing nitrogen, oxygen and boron as well as preparation method and application thereof

Abstract

The invention relates to a condensed ring compound containing nitrogen, oxygen and boron as well as a preparation method and application thereof. The nitrogen-oxygen-boron-containing fused ring compound has a structural general formula shown as a formula (I). The nitrogen-oxygen-boron-containing fused ring compound can improve the luminous efficiency and stability of a photoelectric device and prolong the service life of the photoelectric device. In addition, the synthesis route is simple and convenient, the material cost is low, and amplification and industrial production are facilitated.

Description

Technical Field

[0001] This invention relates to the field of organic functional materials, and more particularly to a nitrogen-oxygen-boron fused ring compound, its preparation method, and its application. Background Technology

[0002] OLED (Organic Light-Emitting Diode), also known as organic electroluminescence display or organic electroluminescence semiconductor, is a current-driven organic light-emitting device. It emits light through the injection and recombination of charge carriers, with the luminous intensity directly proportional to the injected current. Under the influence of an electric field, holes generated at the anode and electrons at the cathode move and are injected into the hole transport layer and electron transport layer, respectively, migrating to the emissive layer. When these two electrons meet in the emissive layer, they generate excitons, which excite the light-emitting molecules to ultimately produce visible light.

[0003] Currently, organic light-emitting diode (OLED) technology has entered the commercialization stage after years of development and is widely used in flat panel displays. OLED displays have advantages such as thinness, high brightness, low power consumption, fast response, high definition, good flexibility, and high luminous efficiency, which can meet consumers' new demands for display technology. However, blue OLEDs still have many problems, such as poor device stability, poor performance, and especially a short lifespan. Summary of the Invention

[0004] Based on this, the present invention provides a nitrogen-oxygen-boron fused ring compound, its preparation method and application. Using this nitrogen-oxygen-boron fused ring compound in optoelectronic devices can improve the luminous efficiency, stability and lifespan of optoelectronic devices.

[0005] The technical solution is as follows:

[0006] A nitrogen-oxygen-boron fused ring compound, the general structural formula of which is shown in formula (I):

[0007]

[0008] Ar1, Ar2, L1, and L2 are each independently selected from substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C1-C30 alkyl mercapto, substituted or unsubstituted C1-C30 alkylamino, substituted or unsubstituted C1-C30 alkyl carbonyl, substituted or unsubstituted C1-C30 alkoxy carbonyl, substituted or unsubstituted aryl with 6-60 ring atoms, substituted or unsubstituted. One or more of the following: heteroaryl group having 5 to 60 ring atoms, substituted or unsubstituted arylamino group having 6 to 60 ring atoms, substituted or unsubstituted aryloxy group having 6 to 60 ring atoms, substituted or unsubstituted arylthiol group having 6 to 60 ring atoms, substituted or unsubstituted heteroarylamino group having 5 to 60 ring atoms, substituted or unsubstituted heteroaryloxy group having 5 to 60 ring atoms, and substituted or unsubstituted heteroarylthiol group having 5 to 60 ring atoms;

[0009] When substituted, each substituent is independently selected from one or more of H, D, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, mercapto, cyano, C1-C30 alkyl, C1-C30 alkoxy, and aryl with 6-30 ring atoms;

[0010] The heteroatoms in the heteroaryl group, the heteroaryloxy group, the heteroarylamino group, and the heteroarylthiol group are each independently selected from one or more of O, P, N, and S.

[0011] The present invention also provides a method for preparing the nitrogen-oxygen-boron fused ring compound as described above.

[0012] The present invention also provides a TADF sensitizer, which includes the nitrogen-oxygen-boron fused-ring compound as described above, or the nitrogen-oxygen-boron fused-ring compound prepared according to the preparation method described above.

[0013] The present invention also provides a luminescent material comprising a luminescent host material, a guest material, and a sensitizer, wherein the sensitizer comprises the TADF sensitizer as described above.

[0014] The present invention also provides an optoelectronic device, which includes a first electrode, a functional layer and a second electrode stacked together;

[0015] The material of the functional layer includes nitrogen-oxygen-boron fused ring compounds as described above, or nitrogen-oxygen-boron fused ring compounds prepared according to the preparation method described above.

[0016] The present invention has at least the following beneficial effects:

[0017] The nitrogen-, oxygen-, and boron-containing fused-ring compounds provided by this invention can improve the performance of optoelectronic devices. Furthermore, the synthetic route for these compounds is simple and convenient, with low material costs, facilitating scale-up and industrial production. Using the materials provided in this application, optoelectronic devices can be fabricated via inkjet printing, meeting commercialization needs. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of an OLED according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the structure of an OLED according to another embodiment of the present invention. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to specific embodiments. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0021] 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 this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] When using “including,” “having,” and “contains” as described herein, the intention is to cover non-exclusive inclusion, unless an explicit qualifying term such as “only,” “consisting of,” etc., is used, in which case another component may be added.

[0023] In this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include at least one of that feature.

[0024] When describing positional relationships, unless otherwise specified, when an element such as a layer, film, or substrate is referred to as being "on" another film layer, it may be directly on the other film layer or there may be intermediate film layers. Furthermore, when a layer is referred to as being "below" another layer, it may be directly below it or there may be one or more intermediate layers. It is also understood that when a layer is referred to as being "between" two layers, it may be the only layer between the two layers, or there may be one or more intermediate layers.

[0025] In this invention, the terms "preferredly," "more preferably," "better," and "even better" refer to embodiments of the invention that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of the invention. That is, in this invention, "preferredly," "more preferably," "better," and "even better" are merely descriptions of more effective implementations or examples, but do not constitute a limitation on the scope of protection of the invention.

[0026] In this invention, terms such as "further," "even more," and "particularly" are used for descriptive purposes and to indicate differences in content, but should not be construed as limiting the scope of protection of this invention.

[0027] In this invention, "at least one" means one or more, such as one, two, or more. "Multiple" or "several" means at least two, such as two, three, etc., and "multi-layered" means at least two layers, such as two layers, three layers, etc., unless otherwise explicitly specified. In the description of this invention, "several" means at least one, such as one, two, etc., unless otherwise explicitly specified.

[0028] When a numerical range is disclosed in this invention, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Further, when the range refers to an integer, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included. Only a few numerical ranges are specifically disclosed herein. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, just as any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form an unspecified range.

[0029] Unless otherwise specified, all steps of this invention may be performed sequentially or randomly. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), indicating that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0030] Unless otherwise stated, a singular term may include a plural term and should not be understood as having a quantity of one.

[0031] Unless otherwise specified, the temperature parameters in this invention can be either constant temperature processing or processing within a certain temperature range. The constant temperature processing allows temperature fluctuations within the precision range controlled by the instrument.

[0032] The weights of the relevant components mentioned in the embodiments of this invention can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this invention is within the scope disclosed in the embodiments of this invention. Specifically, the weights mentioned in the embodiments of this invention can be well-known units of mass in the chemical industry, such as μg, mg, g, and kg.

[0033] In this invention, if the unit of a data range is only followed by the right endpoint, it indicates that the units of the left and right endpoints are the same. For example, 800-850nm means that the units of the left endpoint "800" and the right endpoint "850" are both nm (nanometers).

[0034] In this invention, "above" or "below" both include the number itself. For example, below 1 means less than or equal to 1 (≤1), and above 1 means greater than or equal to 1 (≥1).

[0035] In this invention, "A and B are independently selected from x, y or z" means that A and B are independent events, and event A does not affect the occurrence of event B. Therefore, when A is selected from x, B can be selected from any one of x, y or z; when A is selected from y, B can be selected from any one of x, y or z; when A is selected from z, B can be selected from any one of x, y or z.

[0036] In this invention, "ring atom number" refers to the number of atoms in the ring itself of a structural compound (e.g., monocyclic compound, fused-ring compound, cross-linked compound, carbocyclic compound, heterocyclic compound) obtained by atomic bonding to form a ring. When the ring is substituted by a substituent, the atoms contained in the substituent are not included in the ring-forming atoms. The same applies to the "ring atom number" described below unless otherwise specified. For example, the benzene ring has 6 ring atoms, the naphthalene ring has 10 ring atoms, and the thiophene group has 5 ring atoms.

[0037] In this invention, "alkyl" can refer to a straight-chain, branched, and / or cyclic alkyl group. The number of carbon atoms in an alkyl group can be 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Phrases containing this term, such as "C1-9 alkyl," refer to alkyl groups containing 1 to 9 carbon atoms, and each time it appears, it can independently be C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C7 alkyl, C8 alkyl, or C9 alkyl. Non-limiting examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, etc.

[0038] The term "alkoxy" refers to a group having an "-O-alkyl" group, i.e., an alkyl group as defined above connected to an alkyl structure via an oxygen atom. The C1-C20 alkoxy groups include C1-C19, C1-C14, C1-C12, C1-C6, C1-C4, C1-C15, C1-C10, C1-C8, C1-C5, and C20 alkoxy groups. Suitable examples of phrases containing the C1-C20 alkoxy term include, but are not limited to: methoxy (-O-CH3 or -OMe), ethoxy (-O-CH2CH3 or -OEt), and tert-butoxy (-OC(CH3)3 or -OtBu).

[0039] "Aryl" or "aromatic group" or "aromatic group" refers to an aromatic hydrocarbon group derived from an aromatic ring compound by removing one hydrogen atom. It can be a monocyclic aryl, a fused-ring aryl, or a polycyclic aryl. For polycyclic ring species, at least one is an aromatic ring system. For example, "substituted or unsubstituted aryl having 6 to 40 ring atoms" means a substituted or unsubstituted aryl containing 6 to 40 ring atoms, preferably an aryl having 6 to 30 ring atoms, more preferably an aryl having 6 to 18 ring atoms, particularly preferably an aryl having 6 to 14 ring atoms, and even more particularly preferably an aryl having 6 to 10 ring atoms, and optionally further substituted on the aryl group; suitable examples include, but are not limited to: benzene, biphenyl, terphenyl, naphthalene, anthracene, fluoranthene, phenanthrene, benzo[a]phenanthrene, dinaphthalene, tetraphenyl, pyrene, benzo[a]pyrene, acenaphthene, fluorene and their derivatives. Understandably, multiple aryl groups can also be interrupted by short non-aromatic units (e.g., <10% non-H atoms, such as C, N, or O atoms), specifically acenaphthene, fluorene, or 9,9-diarylfluorene, triarylamine, and diaryl ether systems should also be included in the definition of aryl.

[0040] This invention provides a nitrogen-oxygen-boron fused-ring compound, its preparation method, and its application. This compound has a high reverse intersystem transition rate, avoiding the accumulation and aggregation of triplet excitons and generating exciton quenching. At the same time, the exciton formation and decay processes are carried out in the host and dopant respectively, effectively avoiding the formation of electron traps in the emitter. When this nitrogen-oxygen-boron fused-ring compound is used in optoelectronic devices, it can improve the luminous efficiency, stability, and lifetime of the optoelectronic devices.

[0041] The technical solution is as follows:

[0042] A nitrogen-oxygen-boron fused ring compound, the general structural formula of which is shown in formula (I):

[0043]

[0044] Ar1, Ar2, L1, and L2 are each independently selected from substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C1-C30 alkyl mercapto, substituted or unsubstituted C1-C30 alkylamino, substituted or unsubstituted C1-C30 alkyl carbonyl, substituted or unsubstituted C1-C30 alkoxy carbonyl, substituted or unsubstituted aryl with 6-60 ring atoms, substituted or unsubstituted. One or more of the following: heteroaryl group having 5 to 60 ring atoms, substituted or unsubstituted arylamino group having 6 to 60 ring atoms, substituted or unsubstituted aryloxy group having 6 to 60 ring atoms, substituted or unsubstituted arylthiol group having 6 to 60 ring atoms, substituted or unsubstituted heteroarylamino group having 5 to 60 ring atoms, substituted or unsubstituted heteroaryloxy group having 5 to 60 ring atoms, and substituted or unsubstituted heteroarylthiol group having 5 to 60 ring atoms;

[0045] When substituted, each substituent is independently selected from one or more of H, D, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, mercapto, cyano, C1-C30 alkyl, C1-C30 alkoxy, and aryl with 6-30 ring atoms;

[0046] The heteroatoms in the heteroaryl group, the heteroaryloxy group, the heteroarylamino group, and the heteroarylthiol group are each independently selected from one or more of O, P, N, and S.

[0047] In some embodiments, the nitrogen-oxygen-boron fused ring compound has the general structural formula shown in formula (I-1):

[0048]

[0049] In some implementations, Ar1 and Ar2 are the same.

[0050] In some embodiments, Ar1 and Ar2 are each independently selected from one or a combination of the following groups:

[0051]

[0052] Among them, X 1 Independently selected from N or CR 1 ;

[0053] Y 1 Independently selected from single bonds, N(R) 2 ), C(R 3 R 4 ), N, CR 5 , O or S;

[0054] R 1 ~R 5 It is independently selected from H, C1-C20 alkyl, C1-C20 alkoxy, halogen, amino, cyano, aryl with 6 to 30 carbon atoms, or heteroaryl with 5 to 30 ring atoms.

[0055] In some embodiments, Ar1 and Ar2 are each independently selected from one of the following structures:

[0056]

[0057]

[0058] In some implementations, L1 and L2 are the same.

[0059] In some embodiments, at least one of L1 and L2 is selected from one or more of the following: aryl group with 6 to 40 carbon atoms (substituted or unsubstituted), heteroaryl group with 5 to 40 ring atoms (substituted or unsubstituted), and arylamino group with 6 to 40 ring atoms (substituted or unsubstituted); when substituted, each substituent is independently selected from one or more of the following: H, D, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, mercapto, cyano, C1 to C30 alkyl, C1 to C30 alkoxy, and aryl group with 6 to 30 ring atoms; the heteroatoms in the heteroaryl group are independently selected from one or more of the following: O, P, N, and S.

[0060] In some embodiments, L1 and L2 are each independently selected from one or a combination of the following groups:

[0061]

[0062] Among them, X 1 Independently selected from N or CR 1 ;

[0063] Y 1 Independently selected from single bonds, N(R) 2 ), C(R 3 R 4 ), N, CR 5 , O or S;

[0064] R 1 ~R 5 It is independently selected from H, C1-C20 alkyl, C1-C20 alkoxy, halogen, amino, cyano, aryl with 6 to 30 carbon atoms, or heteroaryl with 5 to 30 ring atoms.

[0065] In some implementations, L1 and L2 are each independently selected from one of the following structures:

[0066]

[0067]

[0068] In some embodiments, Ar1, Ar2, L1 and L2 are each independently selected from aryl groups having 6 to 40 carbon atoms substituted or unsubstituted by at least one R, or heteroaryl groups having 5 to 40 ring atoms substituted or unsubstituted by at least one R.

[0069] When R appears, it is selected from H, alkyl, alkoxy, halogen, amino, cyano, aryl with 6 to 30 carbon atoms, or heteroaryl with 5 to 30 ring atoms.

[0070] In some embodiments, at least one of L1 and L2 is selected from an aryl group having 6 to 40 carbon atoms substituted by R, or a heteroaryl group having 5 to 40 ring atoms substituted by R, and R is a C1 to C20 alkyl group.

[0071] In some embodiments, the nitrogen-oxygen-boron fused ring compound has any of the following structures:

[0072]

[0073]

[0074]

[0075] The present invention also provides a method for preparing the nitrogen-oxygen-boron fused-ring compound as described above, comprising the following steps:

[0076] The compound shown in formula (II) was mixed with NBS and the first intermediate compound shown in formula (III) was prepared by a first bromination reaction;

[0077] The first intermediate compound, ligand, first base, and first catalyst shown in formula (III) are mixed and the second intermediate compound shown in formula (IV) is prepared by coupling reaction.

[0078] The second intermediate compound shown in formula (IV) was mixed with NBS, and the third intermediate compound shown in formula (V) was prepared by a second bromination reaction;

[0079] The fourth intermediate compound, shown in formula (VI), is prepared by mixing the third intermediate compound shown in formula (V), alkyllithium, L1MgBr, L2MgBr, boron trihalide and organic amine, and by a continuous reaction of lithiation-boration-Grignard reaction.

[0080] The fourth intermediate compound shown in formula (VI) was mixed with NBS, and the fifth intermediate compound shown in formula (VII) was prepared by a third bromination reaction;

[0081] The fifth intermediate compound of formula (VII), the compound of formula a-1 or a-2, the compound of formula b-1 or b-1, the second base and the second catalyst are mixed and subjected to a metal coupling reaction to prepare the nitrogen-oxygen-boron fused ring compound of any one of claims 1 to 5.

[0082]

[0083] The definitions of Ar1, Ar2, L1, and L2 are as above.

[0084] In some embodiments, the molar ratio of the second intermediate compound represented by formula (IV) to NBS is 1:(1 to 1.5), including but not limited to 1:1.15, 1:1.2 or 1:1.25.

[0085] In some embodiments, the temperature of the first bromination reaction is 50°C to 75°C, and the time is 1 hour to 4 hours.

[0086] In some embodiments, the first alkali includes one or more of potassium carbonate, potassium phosphate, and cesium carbonate.

[0087] In some embodiments, the molar ratio of the first intermediate compound and the first base represented by formula (III) is 1:(1 to 2), including but not limited to 1:1.15, 1:1.25 or 1:1.85.

[0088] In some embodiments, the ligand is selected from one or more of 18-crown-6 ether and 12-crown-4 ether. The ligand can form a stable complex with an organic cation (increasing the solubility of the metal cation in the first base), increasing its presence time and concentration in the reaction system, thereby increasing the reaction conversion rate and speed.

[0089] In some embodiments, the first catalyst includes one or more of cuprous iodide, cuprous bromide, and cuprous chloride.

[0090] In some embodiments, the molar ratio of the first intermediate compound represented by formula (III) to the first catalyst is 1:(0.15 to 0.25), including but not limited to 1:0.15, 1:0.2 or 1:0.25.

[0091] In some embodiments, the coupling reaction is carried out at a temperature of 160°C to 190°C for a duration of 12 hours to 24 hours.

[0092] In some embodiments, the molar ratio of the second intermediate compound represented by formula (IV) to NBS is 1:(2 to 4.5), including but not limited to 1:2.15, 1:3.2 or 1:4.25.

[0093] In some embodiments, the temperature of the second bromination reaction is 50°C to 75°C, and the time is 1 hour to 4 hours.

[0094] In some embodiments, the alkyllithium reagent includes one or both of n-butyllithium and tert-butyllithium.

[0095] In some embodiments, the molar ratio of the third intermediate compound represented by formula (V) to alkyllithium is 1:(2 to 6), including but not limited to 1:2.2, 1:4.5, 1:5.3 or 1:5.4.

[0096] In some embodiments, the boron trihalide includes one or both of boron tribromide and boron triiodide.

[0097] In some embodiments, the molar ratio of the third intermediate compound represented by formula (V) to boron trihalide is 1:(2 to 6.5), including but not limited to 1:2.2, 1:4.5, 1:5.3 or 1:6.4.

[0098] In some embodiments, the organic amine includes one or both of 1,2,2,6,6-pentamethylpiperidine and N,N-diisopropylethylamine.

[0099] In some embodiments, the molar ratio of the third intermediate compound represented by formula (V) to the organic amine is 1:(2 to 5), including but not limited to 1:2, 1:2.25, 1:3.3 or 1:4.5.

[0100] In some embodiments, the molar ratio of the third intermediate compound represented by formula (V) to the Grignard reagent is 1:(2 to 10), including but not limited to 1:6.2, 1:8.25, 1:9.3 or 1:10.

[0101] In some embodiments, the lithiation reaction temperature is -50°C to 0°C, the boration reaction temperature is -50°C to 120°C, and the Grignard reaction temperature is 10°C to 50°C.

[0102] In some embodiments, the molar ratio of the fourth intermediate compound represented by formula (VI) to NBS is 1:(2 to 2.5), including but not limited to 1:2.15, 1:2.2 or 1:2.5.

[0103] In some embodiments, the temperature of the third bromination reaction is 0°C to 25°C, and the time is 0.5h to 1.5h.

[0104] In some embodiments, the molar ratio of the fifth intermediate compound represented by formula (VII) and the compound represented by formula a-1 is 1:(2 to 4), including but not limited to 1:2.2, 1:3.5, or 1:4. Or the molar ratio of the fifth intermediate compound represented by formula (VII) and the compound represented by formula a-2 is 1:(2 to 4), including but not limited to 1:2.2, 1:3.5, or 1:4.

[0105] In some embodiments, the molar ratio of the fifth intermediate compound b-1 represented by formula (VII) is 1:(2 to 4), including but not limited to 1:2.2, 1:3.5, or 1:4. Or the molar ratio of the fifth intermediate compound b-2 represented by formula (VII) is 1:(2 to 4), including but not limited to 1:2.2, 1:3.5, or 1:4.

[0106] In some embodiments, the second alkali includes one or more of potassium phosphate, potassium carbonate, potassium acetate, and sodium carbonate.

[0107] In some embodiments, the molar ratio of the fifth intermediate compound represented by formula (VII) to the second base is 1:(5 to 10), including but not limited to 1:5, 1:6 or 1:8.

[0108] In some embodiments, the second catalyst includes one or more of Pd(PPh3)4, palladium acetate, palladium trifluoroacetate, palladium diphenylphosphine ferrocene dichloride, bis(tri-tert-butylphosphine)palladium, Pd(dba)2, and Pd2(dba)3.

[0109] In some embodiments, the molar ratio of the fifth intermediate compound represented by formula (VII) to the second catalyst is 1:(0.05 to 0.1), including but not limited to 1:0.05, 1:0.06, 1:0.08 or 1:0.1.

[0110] In some embodiments, the metal coupling reaction temperature is 75°C to 90°C, and the time is 12h to 24h.

[0111] The present invention also provides a TADF sensitizer, which includes the nitrogen-oxygen-boron fused-ring compound as described above, or the nitrogen-oxygen-boron fused-ring compound prepared according to the preparation method described above.

[0112] The present invention also provides a luminescent material comprising a luminescent host material, a guest material, and a sensitizer, wherein the sensitizer comprises the TADF sensitizer as described above.

[0113] In some embodiments, the luminescent material comprises, by weight percentage, 70% to 90% of the luminescent host material, 1% to 6% of the guest material, and 9% to 29% of the sensitizer.

[0114] In some embodiments, the light-emitting host material is selected from one or more of the following structures:

[0115]

[0116]

[0117]

[0118] In some embodiments, the object material is selected from one or more of the following structures:

[0119]

[0120]

[0121] The present invention also provides an optoelectronic device, which includes a first electrode, a functional layer and a second electrode stacked together;

[0122] The material of the functional layer includes nitrogen-oxygen-boron fused ring compounds as described above, or nitrogen-oxygen-boron fused ring compounds prepared according to the preparation method described above.

[0123] Optionally, the functional layer includes a light-emitting layer, the material of which includes nitrogen-oxygen-boron fused-ring compounds as described above, or nitrogen-oxygen-boron fused-ring compounds prepared according to the preparation method described above.

[0124] Optionally, a first transport layer is disposed between the first electrode and the functional layer. The first functional layer is a hole transport layer or an electron transport layer.

[0125] Optionally, a second transport layer is disposed between the second electrode and the functional layer. The second functional layer is an electron transport layer or a hole transport layer.

[0126] In some embodiments, an electron injection layer is further stacked between the electron transport layer and the first or second electrode.

[0127] In some embodiments, a hole injection layer is further stacked between the hole transport layer and the first or second electrode.

[0128] In some embodiments, a refractive layer is further stacked on the surface of the first electrode away from the first functional layer.

[0129] Understandably, the present invention does not impose special requirements on the materials of the first electrode, the electron transport layer, the electron injection layer, the hole transport layer, the hole injection layer, the second electrode, and the refractive layer; all materials are conventional choices in the art.

[0130] In some embodiments, the hole injection layer material can be at least one of the following materials and their derivatives, or materials obtained by doping or passivation: PEODT:PSS (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid)), HAT-CN (2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene). In a specific example, HAT-CN (2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene) is selected as the hole injection material.

[0131] In some embodiments, the hole transport layer material can be at least one of the following materials and their derivatives, or materials obtained by doping or passivation: TFB (poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt-(4,4'-(N-(4-n-butyl)phenyl)-diphenylamine)]), PVK (polyvinylcarbazole), PFB [N,N'-(4-n-butylphenyl)-N,N'-diphenyl-p-phenylenediamine]-[9,9-di-n-octylfluorenyl-2,7-diyl] copolymer, TPD (N,N′-bis(3-methylphenyl)-N,N′- The following materials are used as hole transport materials: diphenyl-1,1′-biphenyl-4,4′-diamine, TCTA (4,4',4”-tris(carbazole-9-yl)triphenylamine), TAPC (4,4′-cyclohexylbis[N,N-di(4-methylphenyl)aniline]), Poly-TBP, Poly-TPD, NPB (N,N'-diphenyl-N,N'-(1-naphthyl)-1,1′-biphenyl-4,4′-diamine), and CBP (4,4′-di(9-carbazole)biphenyl). In a specific example, CBP (4,4′-di(9-carbazole)biphenyl) was selected as the hole transport material.

[0132] In some embodiments, the electron transport layer material can be at least one of the following materials and their derivatives, or materials obtained by doping or passivation: LiQ (lithium 8-hydroxyphosphate), ETI, metal chelates of 8-hydroxyquinoline, and TPBi (1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene). In a specific example, LiQ (lithium 8-hydroxyphosphate) and TPBi (1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene) are selected in a mass ratio of LiQ:TPBi = 2:8.

[0133] In some embodiments, the electron injection layer may be made of at least one of the following materials and their derivatives, or materials obtained by doping or passivation: Yb, LiF, and lithium oxide. In one specific example, Yb is selected.

[0134] In some embodiments, examples of electrode layer (cathode) materials include, but are not limited to: Al, Au, Ag, Ca, Ba, Mg, LiF / Al, MgAg alloy, BaF2 / Al, Cu, Fe, Co, Ni, Mn, Pd, Pt, ITO, etc., and in one specific example, Ag is selected.

[0135] In some embodiments, examples of transparent conductive layer (positive electrode) materials include, but are not limited to, ITO (indium tin oxide), FTO (fluorine-doped SnO2), AZO (aluminum-doped ZnO), indium zinc oxide (IZO), etc., and in a specific example, IZO is selected.

[0136] In some implementations, examples of materials for the refractive layer include, but are not limited to: In a specific example, compound 1 is selected.

[0137] In this invention, without limitation, the thickness of the refractive layer is 10nm to 200nm, the thickness of the electrode layer is 1nm to 200nm, the thickness of the electron injection layer is 1nm to 200nm, the thickness of the electron transport layer is 1nm to 200nm, the thickness of the light-emitting layer is 1nm to 200nm, the thickness of the hole transport layer is 1nm to 200nm, the thickness of the hole injection layer is 1nm to 200nm, and the thickness of the conductive glass layer is 1nm to 200nm.

[0138] See Figure 1 The structure of the optoelectronic device OLED1 includes a first electrode 110, an electron transport layer 120, a light-emitting layer 130, a hole transport layer 140, and a second electrode 150 stacked together.

[0139] The material of the light-emitting layer 130 is selected from the light-emitting materials described above.

[0140] See Figure 2 The structure of the optoelectronic device OLED2 includes a refractive layer 160, a first electrode 110, an electron injection layer 170, an electron transport layer 120, a light-emitting layer 130, a hole transport layer 140, a hole injection layer 180, and a second electrode 150, all stacked together.

[0141] The nitrogen-oxygen-boron-containing fused-ring compounds provided by this invention possess thermally activated delayed fluorescence (TADF) properties. They can capture triplet excitons and rapidly convert them into singlet excitons via upconversion. These singlet excitons are then transferred to the fluorescent dopant via field-shifting (FET) characteristics, effectively preventing excessive concentrations of triplet excitons on the host material, thus avoiding triplet exciton annihilation and the resulting high energy decomposition of the host material. Furthermore, by conducting exciton formation and luminescence in different materials, high-energy excitons during exciton formation prevent decomposition of the luminescent material. Moreover, the synthetic route for these nitrogen-oxygen-boron-containing fused-ring compounds is simple and convenient, with low material costs, facilitating scale-up and industrial production.

[0142] This nitrogen-oxygen-boron fused-ring compound is used in optoelectronic devices. TADF sensitization technology is employed to form excitons through electron-hole recombination in the host material. A sensitizer is then used to establish a FET energy transfer channel between the host material and the guest material (or dopant), enabling the transfer of exciton energy from the host material to the dopant. This improves exciton utilization, avoids the TAR effect between the host material and the dopant, and ultimately enhances the luminous efficiency and extends the lifespan of optoelectronic devices (such as blue OLEDs).

[0143] In addition, inkjet printing technology, a conventional inkjet printing technique can be used to mix different materials of the light-emitting layer (TADF sensitizer combined with the light-emitting host material and guest material to form the light-emitting layer) in a certain proportion to achieve uniform mixing between materials, so that the light emission of optoelectronic devices (such as blue OLED) is more uniform and consistent, and the luminous efficiency and lifespan can be greatly improved to meet commercialization needs.

[0144] The present invention will now be described with reference to embodiments, but the present invention is not limited to the embodiments described below. It should be understood that the appended claims summarize the scope of the present invention. Under the guidance of the inventive concept, those skilled in the art should realize that any changes made to the embodiments of the present invention will be covered by the spirit and scope of the claims of the present invention.

[0145] 1. Compound Synthesis Examples

[0146] Example 1: Preparation of organic compounds having the structure shown in formula (I)

[0147] (1) Synthesis of Compound III

[0148] Compound II (CAS: 135-67-1) (5 mmol, 0.915 g) was added to a 250 mL two-necked flask, along with 100 mL of THF. The flask was placed in a 60 °C bath. NBS (5 mmol, 0.89 g) was dissolved in 50 mL of THF and slowly added dropwise to the reaction apparatus. After the addition was complete, the reaction was allowed to proceed for 1 h. The reaction was then quenched with 50 mL of 1 mol / mL sodium thiosulfate aqueous solution. The reaction solution was then extracted and washed repeatedly 3 to 4 times with dichloromethane (500 mL) and water (200 mL). The crude product was separated by column chromatography using 300 to 400 mesh silica gel mixed with PE as the eluent. Compound III was obtained as a colorless liquid with a yield of 90%.

[0149] (2) Synthesis of compound IV

[0150] Compound III (9 mmol, 2196 mg), cuprous iodide (1.8 mmol, 172 mg), 18-crown-6 (1.8 mmol, 476 mg), and potassium carbonate (13.5 mmol, 1870 mg) were added to a 100 mL two-necked flask. Then, 30 mL of o-DCB was added, nitrogen gas was introduced, and the mixture was evacuated using a vacuum pump for 20 min. The reaction solution was stirred and heated to 180 °C for 24 h. The reaction was stopped and cooled to room temperature. The reaction solvent was removed by vacuum distillation. The remaining reaction solution was then extracted and washed repeatedly 3 to 4 times with dichloromethane (800 mL) and water (250 mL). The obtained organic phase was dried with anhydrous magnesium sulfate, filtered, concentrated, and separated by column chromatography with an eluent PE / EA = 10:2. Compound IV was obtained as a white solid with a yield of 20%.

[0151] (3) Synthesis of compound V

[0152] Compound IV (1 mmol, 0.33 g) was added to a 250 mL two-necked flask, along with 10 mL of THF. The flask was placed in a 60 °C bath. NBS (2 mmol, 0.356 g) was dissolved in 20 mL of THF and slowly added dropwise to the reaction apparatus. After the addition was complete, the reaction was allowed to proceed for 1 h. The reaction was then quenched with 10 mL of 1 mol / mL sodium thiosulfate aqueous solution. The reaction solution was then extracted and washed repeatedly 3 to 4 times with dichloromethane (200 mL) and water (100 mL). The crude product was separated by column chromatography using 300 to 400 mesh silica gel as the eluent. Compound V was obtained as a colorless liquid with a yield of 60%.

[0153] (4) Synthesis of compound VI

[0154] (4.1) Synthesize compound VI-1 from compound V as a raw material

[0155] Compound V (2.53 mmol, 1310 mg) and ultra-dry o-xylene (100 ml) were added to a 250 ml two-necked flask under a nitrogen atmosphere. The mixture was stirred and cooled to 0 °C. Then, n-butyllithium (4 ml, 2.5 M, 10 mmol) containing a hexane solution was slowly added using a syringe. The mixture was then heated to 50 °C and reacted for 2 h. Subsequently, the reaction apparatus was cooled to -40 °C, and boron tribromide (2.5 g, 10 mmol) was slowly added using a syringe. The mixture was then heated to room temperature (25 °C) and reacted for 1 h. Finally, the mixture was cooled to 0 °C, and N,N-diisopropylethylamine (2.1 ml, 12 mmol) was added. The temperature was then raised to 120°C and reacted for 24 h. Subsequently, the temperature was lowered to 25°C, and 20 ml (1.0 M, 20 mmol) of 4-tert-butylphenyl magnesium bromide dissolved in THF was added. The reaction was stopped after 12 h. The resulting reaction solution was subjected to vacuum distillation to remove the reaction solvent. The remaining reaction solution was then extracted with dichloromethane (100 ml) and water (100 ml). The resulting organic phase was dried with anhydrous sodium sulfate and purified by silica gel column chromatography using dichloromethane / petroleum ether (3:7) as eluent to obtain compound VI-1 as a pale yellow solid with a yield of 50%.

[0156] (4.2) Compounds VI-2, VI-3, VI-4, VI-5 and VI-6 were synthesized using the same method as compound VI-1, except that compound 4-tert-butylphenyl magnesium bromide was replaced with raw material 2. See Table 1 for details.

[0157] Table 1

[0158]

[0159]

[0160]

[0161] (5) Synthesis of compound VII-1

[0162] (5.1) Preparation of compound VII-1 from compound VI-1

[0163] Compound VI-1 (5 mmol, 3.225 g) was added to a 250 mL two-necked flask, and 100 mL of THF was added. The flask was placed in a 0 °C bath. NBS (12 mmol, 2.136 g) was dissolved in 50 mL of THF and slowly added dropwise to the reaction apparatus. After the addition was complete, the reaction was allowed to proceed for 2 h. The reaction was quenched with 50 mL of 1 mol / mL sodium thiosulfate aqueous solution. The reaction solution was then extracted and washed repeatedly 3 to 4 times with dichloromethane (500 mL) and water (200 mL). The crude product was separated by column chromatography with silica gel of 300 to 400 mesh and PE as the eluent. Compound III was obtained as a colorless liquid with a yield of 85%.

[0164] (5.2) Compounds VIII-2, VII-3, VII-4, VII-5, VII-6 and VII-7 were synthesized according to the method of synthesizing compound VII-1, except that compound VII-1 was replaced with raw material 1. See Table 2 for details.

[0165] Table 2

[0166]

[0167]

[0168]

[0169] (6) Synthesis of compound VII-1

[0170] (6.1) Compound M46- was prepared from compound VII-1.

[0171] Compound VII-1 (1 mmol, 1844 mg), 2-furanboronic acid (2.5 mmol, 280 mg) (CAS: 13331-23-2), Pd(PPh3)4 (0.125 mmol, 144 mg), and potassium phosphate (12.5 mmol, 1060 mg) were added to a 200 mL two-necked flask. Then, 100 mL of redistilled tetrahydrofuran was added, nitrogen gas was introduced, and the mixture was evacuated for 20 min using a vacuum pump. The reaction solution was stirred and heated to 85 °C for 24 h. The reaction was stopped and cooled to room temperature. The reaction solution was extracted and washed repeatedly 3 to 4 times with dichloromethane (800 mL) and water (250 mL). The obtained organic phase was dried with anhydrous magnesium sulfate, filtered, concentrated, and separated by column chromatography with an eluent PE / EA = 10:2. Compound M4 was obtained as a pale yellow solid with a yield of 80%.

[0172] (6.2) Compounds M5, M6, M12, M14, M15, M16, M17, M19 and M20 were synthesized using the same method as compound M4, except that compound VII-1 was replaced with raw material 2 and 2-furanboronic acid was replaced with raw material 1. See Table 3 for details.

[0173] Table 3

[0174]

[0175]

[0176]

[0177] Table 4 lists compounds M4, M5, M6, M12, M14, M15, M16, M17, M19, and M20. 1 HNMR data.

[0178] Table 4

[0179]

[0180]

[0181]

[0182] The device fabrication method is as follows:

[0183] Indium zinc oxide (IZO) coated glass (specifications: thickness 75nm, sheet resistance 10Ωm) -2 Pretreatment of the ITO glass substrate (30mm x 30mm): The substrate was sequentially cleaned using a cleaning machine, with each cleaning cycle lasting 120 seconds, to thoroughly remove stains and dust from the surface. It was then baked at 230℃ for 30 minutes. Afterward, it was dried in an electric heating oven for 24 hours. The dried glass substrate was then subjected to UV exposure and O2 plasma treatment for 15 minutes to reduce surface enthalpy. The pretreated ITO glass substrate was used as the device anode. Ink containing dissolved HI material was then poured into the inkjet printer cartridge in a nitrogen glove box, injecting 9 picoliters of HI ink into each pixel. Vacuum treatment (VD) was then performed for 5 minutes (vacuum degree 1 × 10⁻⁶). -4 A 30 nm thick HI layer was formed using mPa, and annealed at 230 °C for 30 minutes. Then, the hole transport layer material (concentration 30 mg / ml) dissolved in a mixed solution of xylene and cyclohexylbenzene was filtered and filled into an inkjet printer cartridge. 25 picoliters of HT layer ink were injected into each pixel and subjected to vacuum distillation (VD) for 5 minutes (vacuum degree 1 × 10⁻⁶ mPa). -4A 25nm thick HT layer was formed using mPa, and annealed at 230℃ for 30 minutes. The dissolved luminescent material (concentration 20mg / ml) was then formulated into ink and filled into the inkjet printer cartridge. 40 picoliters were then applied to each pixel of the HT layer and vacuum-dried for 5 minutes (vacuum degree 1×10⁻⁶). - 4 An EML layer was formed by applying a solution of mPa, which was then annealed at 140°C for 20 min to a thickness of 45 nm. The resulting layer was then transferred to a vacuum evaporation chamber (vacuum degree 5 × 10⁻⁶ mPa). -7 Vacuum evaporation was performed on the EML layer to form an electron transport layer (30 nm) using a mask. Then, 1 nm of Yb was deposited on top of the electron transport layer to form an electron injection layer. Next, 20 nm thick Ag was deposited on top of the Yb to form a cathode. Then, a refracting layer CPL (60 nm) was deposited. Finally, the device was UV cured and encapsulated, and then baked for 20 min to prepare a complete organic electroluminescent device corresponding to Examples 1-10 and Comparative Examples 1-9.

[0184] One type of organic electroluminescent device structure is: ITO / HI (30nm) / HT (25nm) / EML (35nm) / ET (30nm) / Yb (1nm) / Ag (20nm) / CPL (80nm).

[0185] In this embodiment, HAT-CN (2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene) was selected as the hole injection material, CBP (4,4'-bis(9-carbazole)biphenyl) was selected as the hole transport material, and LiQ (lithium 8-hydroxyphosphate) and TPBi (1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene) in a mass ratio of LiQ:TPBi = 2:8 were selected as the electron transport material. The EML materials and their ratios are shown in Table 5.

[0186]

[0187] Table 5

[0188]

[0189]

[0190] Device performance testing:

[0191] The EQE relative value test and the full width at half maximum (FWHM) test were performed on the optoelectronic devices of Device Examples 1 to 10 and Device Comparative Examples 1 to 8, respectively.

[0192] The test method for the relative value of EQE is as follows: Using the Fostar FPD optical property measurement equipment, an efficiency testing system was built by controlling a QE PRO spectrometer, Keithley 2400, and Keithley 6485 via LabVIEW. Parameters such as voltage, current, brightness, and emission spectrum were measured to obtain the maximum brightness. The external quantum efficiency (EQE) of the device was then calculated using the following formula:

[0193]

[0194] In the formula, ηe is the optical output coupling efficiency, ηr is the ratio of the number of recombinated carriers to the number of injected carriers, χ is the ratio of the number of excitons that generate photons to the total number of excitons, KR is the radiation process rate, and KNR is the non-radiative process rate.

[0195] The test method for the relative value of lifetime T95@1000nit is as follows: Under constant current or voltage drive, the time required for the brightness of the device to decrease to a certain percentage of its maximum brightness is defined as T95. This lifetime is the measured lifetime. To shorten the testing cycle, device lifetime testing is usually performed at high brightness by accelerating device aging, and the lifetime at high brightness is obtained by fitting the extended exponential decay brightness decay formula. For example, the lifetime at 1000nit is measured as T95@1000nit. The specific calculation formula is as follows:

[0196]

[0197] Among them, T95 L For longer lifespan at low brightness, T95 H For the measured lifetime under high brightness, L H To accelerate the device to its maximum brightness, L L The value is 1000 nits, and A is the acceleration factor with a value of 1.7. The measured performance of each device is shown in Table 6.

[0198] Table 6

[0199]

[0200]

[0201] As shown in Table 6, when using the boron-nitrogen material of this application as a TADF sensitizer to fabricate OLED devices compared to using TADF sensitizer or no sensitizer in the comparative example, the OLED devices fabricated using the boron-nitrogen material of this application show significantly improved device lifetime, narrower half-width, and higher EQE efficiency when the brightness decays to 95% at 1000 nits.

[0202] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0203] The embodiments described above merely illustrate several implementations of the present invention and should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A nitrogen-oxygen-boron fused-ring compound, characterized in that, Its general structural formula is shown in equation (I): Ar1, Ar2, L1, and L2 are each independently selected from substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C1-C30 alkyl mercapto, substituted or unsubstituted C1-C30 alkylamino, substituted or unsubstituted C1-C30 alkyl carbonyl, substituted or unsubstituted C1-C30 alkoxy carbonyl, substituted or unsubstituted aryl with 6-60 ring atoms, substituted or unsubstituted. One or more of the following: heteroaryl group having 5 to 60 ring atoms, substituted or unsubstituted arylamino group having 6 to 60 ring atoms, substituted or unsubstituted aryloxy group having 6 to 60 ring atoms, substituted or unsubstituted arylthiol group having 6 to 60 ring atoms, substituted or unsubstituted heteroarylamino group having 5 to 60 ring atoms, substituted or unsubstituted heteroaryloxy group having 5 to 60 ring atoms, and substituted or unsubstituted heteroarylthiol group having 5 to 60 ring atoms; When substituted, each substituent is independently selected from one or more of H, D, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, mercapto, cyano, C1-C30 alkyl, C1-C30 alkoxy, and aryl with 6-30 ring atoms; The heteroatoms in the heteroaryl group, the heteroaryloxy group, the heteroarylamino group, and the heteroarylthiol group are each independently selected from one or more of O, P, N, and S.

2. The nitrogen-oxygen-boron fused-ring compound according to claim 1, characterized in that, Satisfy at least one of the following conditions (1) to (3): (1) Ar1 and Ar2 are the same; (2) L1 and L2 are the same; (3) At least one of L1 and L2 is selected from one or more of the following: aryl group with 6 to 40 carbon atoms (substituted or unsubstituted), heteroaryl group with 5 to 40 ring atoms (substituted or unsubstituted), and arylamino group with 6 to 40 ring atoms (substituted or unsubstituted); when substituted, each substituent is independently selected from one or more of the following: H, D, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, mercapto, cyano, C1 to C30 alkyl, C1 to C30 alkoxy, and aryl group with 6 to 30 ring atoms; the heteroatoms in the heteroaryl group are independently selected from one or more of the following: O, P, N, and S.

3. The nitrogen-oxygen-boron fused-ring compound according to any one of claims 1 to 2, characterized in that, The Ar1 and Ar2 are each independently selected from one or a combination of the following groups: Among them, X 1 Independently selected from N or CR 1 ; Y 1 Independently selected from single bonds, N(R) 2 ), C(R 3 R 4 ), N, CR 5 , O or S; R 1 ~R 5 It is independently selected from H, C1-C20 alkyl, C1-C20 alkoxy, halogen, amino, cyano, aryl with 6 to 30 carbon atoms or heteroaryl with 5 to 30 ring atoms; And / or, L1 and L2 are each independently selected from one or a combination of the following groups: Among them, X 1 Independently selected from N or CR 1 ; Y 1 Independently selected from single bonds, N(R) 2 ), C(R 3 R 4 ), N, CR 5 , O or S; R 1 ~R 5 It is independently selected from H, C1-C20 alkyl, C1-C20 alkoxy, halogen, amino, cyano, aryl with 6 to 30 carbon atoms, or heteroaryl with 5 to 30 ring atoms.

4. The nitrogen-oxygen-boron fused-ring compound according to claim 3, characterized in that, Ar1 and Ar2 are each independently selected from one of the following structures: And / or, L1 and L2 are each independently selected from one of the following structures:

5. The nitrogen-oxygen-boron fused-ring compound according to claim 1, characterized in that, It has any of the following structures:

6. A method for preparing a nitrogen-oxygen-boron fused-ring compound according to any one of claims 1 to 5, characterized in that, Includes the following steps: The compound shown in formula (II) was mixed with NBS and the first intermediate compound shown in formula (III) was prepared by a first bromination reaction; The first intermediate compound, ligand, first base, and first catalyst shown in formula (III) are mixed and the second intermediate compound shown in formula (IV) is prepared by coupling reaction. The second intermediate compound shown in formula (IV) was mixed with NBS, and the third intermediate compound shown in formula (V) was prepared by a second bromination reaction; The fourth intermediate compound, shown in formula (VI), is prepared by mixing the third intermediate compound shown in formula (V), alkyllithium, L1MgBr, L2MgBr, boron trihalide and organic amine, and by a continuous reaction of lithiation-boration-Grignard reaction. The fourth intermediate compound shown in formula (VI) was mixed with NBS, and the fifth intermediate compound shown in formula (VII) was prepared by a third bromination reaction; The fifth intermediate compound of formula (VII), the compound of formula a-1 or a-2, the compound of formula b-1 or b-1, the second base and the second catalyst are mixed and subjected to a metal coupling reaction to prepare the nitrogen-oxygen-boron fused ring compound of any one of claims 1 to 5. The definitions of Ar1, Ar2, L1, and L2 are the same as those in any one of claims 1 to 5.

7. The method for preparing nitrogen-oxygen-boron fused-ring compounds according to claim 6, characterized in that, Satisfy at least one of the following (1) to (26): (1) The molar ratio of the second intermediate compound shown in formula (IV) to NBS is 1:(1~1.5); (2) The temperature for the first bromination reaction is 50℃~75℃, and the time is 1h~4h; (3) The first base includes one or more of potassium carbonate, potassium phosphate and cesium carbonate; (4) The molar ratio of the first intermediate compound and the first base shown in formula (III) is 1:(1~2); (5) The first catalyst comprises one or more of cuprous iodide, cuprous bromide and cuprous chloride; (6) The molar ratio of the first intermediate compound and the first catalyst shown in formula (III) is 1:(0.15~0.25); (7) The temperature of the coupling reaction is 160℃~190℃ and the time is 12h~24h; (8) The molar ratio of the second intermediate compound shown in formula (IV) to NBS is 1:(2-4.5); (9) The temperature for the second bromination reaction is 50℃~75℃, and the time is 1h~4h; (10) The alkyl lithium reagent includes one or both of n-butyllithium and tert-butyllithium; (11) The molar ratio of the third intermediate compound shown in formula (V) to alkyl lithium is 1:(2-6); (12) The boron trihalide includes one or both of boron tribromide and boron triiodide; (13) The molar ratio of the third intermediate compound shown in formula (V) to boron trihalide is 1:(2-6.5); (14) The organic amine includes one or two of 1,2,2,6,6-pentamethylpiperidine and N,N-diisopropylethylamine; (15) The molar ratio of the third intermediate compound shown in formula (V) to the organic amine is 1:(2-5); (16) The molar ratio of the third intermediate compound shown in formula (V) to the Grignard reagent is 1:(2-10); (17) The temperature of the lithiation reaction is -50℃ to 0℃, the temperature of the boration reaction is -50℃ to 120℃, and the temperature of the Grignard reaction is 10℃ to 50℃; (18) The molar ratio of the fourth intermediate compound shown in formula (VI) to NBS is 1:(2-2.5); (19) The temperature for the third bromination reaction is 0℃~25℃, and the time is 0.5h~1.5h; (20) The molar ratio of the fifth intermediate compound represented by formula (VII) to the compound represented by formula a-1 is 1:(2-4) or the molar ratio of the fifth intermediate compound represented by formula (VII) to the compound represented by formula a-2 is 1:(2-4); (21) The molar ratio of the fifth intermediate compound shown in formula (VII) to the compound shown in formula b-1 is 1:(2-4) or the molar ratio of the fifth intermediate compound shown in formula (VII) to the compound shown in formula b-2 is 1:(2-4); (22) The second base includes one or more of potassium phosphate, potassium carbonate, potassium acetate and sodium carbonate; (23) The molar ratio of the fifth intermediate compound shown in formula (VII) to the second base is 1:(5-10); (24) The second catalyst includes one or more of Pd(PPh3)4, palladium acetate, palladium trifluoroacetate, palladium diphenylphosphine ferrocene dichloride, bis(tri-tert-butylphosphine)palladium, Pd(dba)2 and Pd2(dba)3; (25) The molar ratio of the fifth intermediate compound shown in formula (VII) to the second catalyst is 1:(0.05~0.1); (26) The metal coupling reaction temperature is 75℃~90℃ and the time is 12h~24h.

8. A TADF sensitizer, characterized in that, This includes nitrogen-oxygen-boron fused-ring compounds as described in any one of claims 1 to 5, or nitrogen-oxygen-boron fused-ring compounds prepared by the preparation method according to claim 6 or 7.

9. A luminescent material, characterized in that, It includes a light-emitting host material, a guest material, and a sensitizer, wherein the sensitizer includes the TADF sensitizer as described in claim 8.

10. The luminescent material according to claim 9, characterized in that, The luminescent material comprises, by weight percentage, 70% to 90% of the luminescent host material, 1% to 6% of the guest material, and 9% to 29% of the sensitizer; Optionally, the light-emitting host material is selected from one or more of the following structures: Optionally, the object material is selected from one or more of the following structures:

11. An optoelectronic device, characterized in that, It includes a first electrode, a functional layer, and a second electrode stacked together; The material of the functional layer includes the nitrogen-oxygen-boron fused ring compound as described in any one of claims 1 to 5, or the nitrogen-oxygen-boron fused ring compound prepared by the preparation method according to claim 6 or 7.

12. The optoelectronic device according to claim 11, characterized in that, The functional layer includes a light-emitting layer, the material of which includes the nitrogen-oxygen-boron fused-ring compound as described in any one of claims 1 to 5, or the nitrogen-oxygen-boron fused-ring compound prepared by the preparation method according to claim 6 or 7.

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