Organic compound for organic electroluminescence device and organic electroluminescence device

Abstract

An organic compound characterized by having a structure represented by formula (1): wherein X 1 and X 2 are each independently selected from CR 1 R 2 , NR 3 , O, S, or SiR 4 R 5 ; when any one or several of R 1 to R 5 are present, they are optionally annelated with ring A or ring D; ring A, ring D, and ring E are each independently selected from one of a substituted or unsubstituted C5-C30 aromatic ring, C3-C30 aromatic heterocycle, and at least one has a structure represented by formula (a) which is fused with ring A, ring D, and ring E through ring F; ring F and ring G are each independently selected from one of a substituted or unsubstituted C5-C23 aromatic ring, C3-C23 aromatic heterocycle; Y 1 and Y 2 are each independently selected from CR 6 R 7 , NR 8 , O, S, or SiR 9 R 10 ; R 1 to R 10 are independently selected from one of hydrogen, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, amino, substituted or unsubstituted C1-C10 silyl, C6-C30 aryl, C3-C30 heteroaryl.

Description

Technical Field

[0001] This invention relates to the field of organic light-emitting materials technology, specifically to an organic compound and its applications, as well as an organic electroluminescent device containing the same. Background Technology

[0002] In recent years, optoelectronic devices based on organic materials have become increasingly popular. The inherent flexibility of organic materials makes them ideal for fabrication on flexible substrates, allowing for the design and production of aesthetically pleasing and stylish optoelectronic products, offering unparalleled advantages over inorganic materials. Examples of such organic optoelectronic devices include organic light-emitting diodes (OLEDs), organic field-effect transistors, organic photovoltaic cells, and organic sensors. OLEDs, in particular, have developed rapidly and have already achieved commercial success in the information display field. OLEDs can provide highly saturated red, green, and blue colors, and full-color displays made with them do not require an additional backlight, offering advantages such as vibrant colors, thinness, and flexibility.

[0003] The core of an OLED device is a thin-film structure containing various organic functional materials. Common functionalized organic materials include: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, as well as light-emitting host materials and light-emitting guest materials (dyes). When an electric current is applied, electrons and holes are injected and transported to the light-emitting region, where they recombine, thereby generating excitons and emitting light.

[0004] Various organic materials have been developed and combined with unique device structures to improve carrier mobility, regulate carrier balance, break through electroluminescence efficiency barriers, and delay device decay. For quantum mechanical reasons, common fluorescent emitters primarily utilize singlet excitons generated when electrons and empty blood combine to emit light, and are still widely used in various OLED products. Some metal complexes, such as iridium complexes, can simultaneously utilize triplet and singlet excitons for light emission, and are called phosphorescent emitters, with energy conversion efficiencies up to four times higher than traditional fluorescent emitters. Thermally excited delayed fluorescence (TADF) technology promotes the transition from triplet to singlet excitons, achieving high luminescence efficiency without the use of metal complexes, while still effectively utilizing triplet excitons. Thermally excited sensitized fluorescence (TASF) technology uses materials with TADF properties to sensitize the emitter through energy transfer, also achieving high luminescence efficiency.

[0005] Recently, literature has reported ultrapure blue fluorescent compounds C1 and C2 based on the BN resonance structure and TADF (Thermally Activated Delayed Fluorescence). These compounds form a rigid polycyclic aromatic skeleton composed of B, N, and a benzene ring. The nitrogen atom exhibits a resonance effect opposite to that of the boron atom, and this opposite resonance effect is enhanced at its para position. Therefore, this effect can clearly separate the HOMO and LUMO orbitals, thus exhibiting certain TADF characteristics.

[0006] Summary of the Invention

[0007] The problem the invention aims to solve

[0008] As OLED products gradually enter the market, people have increasingly higher requirements for the performance of these products. Current OLED materials and device structures cannot fully solve the problems related to efficiency, lifespan, and cost of OLED products. This problem is particularly prominent in deep blue light devices.

[0009] In view of the problems of the prior art, the object of the present invention is to provide a new class of compounds for organic electroluminescent devices, which can emit deep blue light, meeting the ever-increasing demands for the photoelectric performance and lifespan of OLED devices. In this application, unless otherwise specified, "deep blue light" refers to light with a wavelength of approximately 440 nm to 470 nm.

[0010] Solution to the problem

[0011] Through careful consideration and continuous experimentation, the researchers of this invention have proposed an ingenious molecular design scheme. Surprisingly, the compounds obtained through this scheme are highly suitable for application in OLEDs, and the resulting devices exhibit excellent performance, meeting the required specifications.

[0012] Specifically, one object of the present invention is to provide an organic compound characterized by having a structure as shown in formula (1):

[0013]

[0014] in,

[0015] X 1 and X 2 Each independently selected from CR 1 R 2 NR 3 O, S or SiR 4 R5 One of them;

[0016] When R 1 ~R 5 When any one or more of them exist, it can be chosen to form a ring with ring A or ring D;

[0017] Ring A, ring D and ring E are each independently selected from one of substituted or unsubstituted C5-C30 aromatic rings and substituted or unsubstituted C3-C30 aromatic heterocycles, and at least one has the structure shown in formula (a), the structure shown in (a) being fused with ring A, ring D and ring E through ring F;

[0018] Ring F and ring G are each independently selected from one of substituted or unsubstituted C5-C23 aromatic rings or substituted or unsubstituted C3-C23 aromatic heterocycles;

[0019] Y 1 and Y 2 Each independently selected from CR 6 R 7 NR 8 O, S or SiR 9 R 10 One of them;

[0020] R 1 ~R 10 It is independently selected from one of hydrogen, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, amino, substituted or unsubstituted C1-C10 silyl, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl;

[0021] When the above-mentioned groups contain substituents, the substituents are selected from one or a combination of at least two of the following: halogen, cyano, nitro, hydroxyl, C1-C10 chain alkyl, C3-C10 cycloalkyl, C1-C10 alkoxy, C1-C10 thioalkoxy, C1-C10 silyl, amino, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 aryl, and C3-C30 heteroaryl.

[0022] The specific reason why the above compounds of the present invention have excellent properties as luminescent materials is not yet clear, and the speculation is as follows: the compounds satisfying the structure of general formula (1) defined in the present invention have a suitable rigid conjugated structure as the parent core, and connect specific aromatic groups to the parent core through methylene, imino, O or S, etc., while breaking the conjugated structure between the parent core and the groups, so that they can exhibit high external quantum efficiency and low turn-on voltage in OLED devices. When the compound obtained by connecting the specific parent core and the specific aromatic group through the above specific manner is used as a luminescent layer dye, it can avoid the red shift of the light color and improve the light color purity while improving the voltage and efficiency of the device.

[0023] In the present invention, the "substituted or unsubstituted" group may be substituted with one substituent, or may be substituted with a plurality of substituents. When there are a plurality of substituents, they may be selected from different substituents. When the same expression is involved in the present invention, they all have the same meaning, and the selection range of the substituents is as shown above and will not be repeated one by one.

[0024] In this specification, the expression Ca to Cb means that the number of carbon atoms contained in the group is a to b. Unless otherwise specified, generally, the number of carbon atoms does not include the carbon atoms of the substituents.

[0025] In this specification, the expression of a ring structure crossed by "-" means that the connection site is any position on the ring structure where a bond can be formed.

[0026] In this specification, "each independently" means that when there are multiple subjects, they may be the same or different from each other.

[0027] In the present invention, for the expression of chemical elements, unless otherwise specified, it usually includes the concept of isotopes with the same chemical properties. For example, the expression "hydrogen (H)" also includes isotopes with the same chemical properties 1 H (protium, also denoted as H), 2 H (deuterium, also denoted as D); carbon (C) includes 12 C, 13 C, etc., which will not be elaborated further.

[0028] The heteroatom in the present invention generally refers to an atom or atomic group selected from N, O, S, P, Si and Se, preferably selected from N, O and S.

[0029] In this specification, examples of halogen include fluorine, chlorine, bromine, iodine and the like.

[0030] In this invention, a monocyclic aryl group refers to a molecule containing one or at least two phenyl groups. When the molecule contains at least two phenyl groups, the phenyl groups are independent of each other and connected by single bonds, such as phenyl, diphenyl, terphenyl, etc. Fused-ring aryl groups refer to a molecule containing at least two benzene rings, but the benzene rings are not independent of each other, but are fused together by sharing ring edges, such as naphthyl, anthracene, etc. A monocyclic heteroaryl group refers to a molecule containing at least one heteroaryl group. When the molecule contains one heteroaryl group and other groups (such as aryl, heteroaryl, alkyl, etc.), the heteroaryl group and other groups are independent of each other and connected by single bonds, such as pyridine, furan, thiophene, etc. Fused-ring heteroaryl groups refer to a molecule formed by the fusion of at least one phenyl group and at least one heteroaryl group, or a molecule formed by the fusion of at least two heteroaryl rings, such as quinoline, isoquinoline, benzofuran, dibenzofuran, benzothiophene, dibenzothiophene, etc.

[0031] In this invention, unless otherwise specified, aryl and heteroaryl groups include both monocyclic and fused-ring types.

[0032] In this invention, unless otherwise specified, the substituents do not fuse with the group to which they belong.

[0033] The preferred organic compound of the present invention is X. 1 and X 2 Each independently selected from NR 3 One of O or S. The organic compound of the present invention is more preferably X. 1 and X 2 At least one is NR 3 The R 3 It is one of the substituted or unsubstituted C6-C30 aryl groups or the substituted or unsubstituted C3-C30 heteroaryl groups.

[0034] By configuring the organic compound of the present invention with the above-described structure, it is possible to achieve higher carrier transport performance.

[0035] The organic compound of the present invention is preferably Y. 1 and Y 2 Each independently selected from CR 6 R 7 NR 8 Or one of O; more preferably Y 1 and Y 2 At least one is a CR 6 R 7 Further optimization of Y 1 and Y 2 All are CR 6 R 7 .

[0036] The organic compound of the present invention is preferably R. 6 and R7 Each is independently selected from one of hydrogen, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl;

[0037] More preferably R 6 and R 7 Each is independently selected from hydrogen or one of the following groups:

[0038]

[0039] Further optimization of R 6 and R 7 All are methyl groups.

[0040] By configuring the organic compound of the present invention with the above-described structure, it is possible to avoid redshift of light color and improve the purity of light color.

[0041] The organic compound of the present invention preferably has ring F selected from one of substituted or unsubstituted C5-C14 aromatic rings and substituted or unsubstituted C3-C14 aromatic heterocycles; more preferably, it is selected from one of substituted or unsubstituted C5-C10 aromatic rings and substituted or unsubstituted C3-C10 N-containing aromatic heterocycles; and even more preferably, it has the structure shown in formula (b):

[0042]

[0043] Where * represents Y 1 Y 2 The site of ring fusion where the ring is located, ring F passes through Z. 1 and Z 2 Z 2 and Z 3 Or Z 3 and Z 4 Fusing with the parent nucleus, Z 1 ~Z 4 Each is independently selected from C and CR. 11 One of N; the R 11 Each of the following is independently selected from hydrogen, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C1-C10 silyl, amino, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl, wherein R 11 It can be optionally linked with an adjacent aromatic ring or heterocyclic aromatic ring to form a ring;

[0044] Further optimize Z1 ~Z 4 Each independently for CR 11 The R 11 Each is independently selected from hydrogen or one of the following groups:

[0045]

[0046] By configuring the organic compound of the present invention with the above-described structure, higher external quantum efficiency and lower voltage can be exhibited in OLED devices.

[0047] The organic compounds of the present invention preferably have ring A, ring D and ring E each independently selected from one of substituted or unsubstituted C5-C14 aromatic rings and substituted or unsubstituted C3-C14 aromatic heterocycles, and at least one having the structure shown in formula (a);

[0048] More preferably, ring A and ring D are each independently selected from the structure shown in formula (c) or formula (a), ring E is the structure shown in formula (c') or formula (a), and at least one of ring A, ring D and ring D has the structure shown in formula (a):

[0049]

[0050] Where * represents a site connected to the parent nucleus, Z 5 ~Z 8 Selected independently from C and CR 11 One of N; the R 11 Each of the following is independently selected from hydrogen, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C1-C10 silyl, amino, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryl, and substituted or unsubstituted C3-C30 heteroaryl, wherein R 11 It can be optionally linked with an adjacent aromatic ring or heterocyclic aromatic ring to form a ring;

[0051] Further preferred is that at least one of rings A and D has the structure shown in equation (a).

[0052] In addition, Z is preferred. 5 ~Z 8 CR independently 11 The R 11 Each is independently selected from hydrogen or one of the following groups:

[0053]

[0054] By configuring the organic compound of the present invention with the above-described structure, higher external quantum efficiency and lower voltage can be exhibited in OLED devices.

[0055] The organic compound of the present invention preferably has ring G selected from one of substituted or unsubstituted C5-C14 aromatic rings and substituted or unsubstituted C3-C14 aromatic heterocycles;

[0056] More preferably, it is selected from one of the substituted or unsubstituted C5-C10 aromatic rings, or one of the substituted or unsubstituted C3-C10 N-containing aromatic heterocycles;

[0057] A further preferred configuration is the structure shown in formula (b'):

[0058]

[0059] Where * represents Y 1 Y 2 The site of ring fusion where the ring is located, Z 1’ ~Z 4’ Selected independently from C and CR 12 One of N; the R 12 Independently selected from one of hydrogen, halogen, cyano, nitro, hydroxyl, substituted or unsubstituted C1-C10 chain alkyl, substituted or unsubstituted C3-C10 cycloalkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C1-C10 silyl, amino, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl, wherein R 12 It can be fused with the aromatic ring or aromatic heterocyclic ring to which it is attached to form a ring.

[0060] By configuring the organic compound of the present invention with the above-described structure, higher external quantum efficiency and lower voltage can be exhibited in OLED devices.

[0061] Examples of C1-C10 alkyl groups mentioned in this invention include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, n-octyl, and n-nonyl.

[0062] Examples of C3-C10 cycloalkyl groups mentioned in this invention include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclodecyl.

[0063] Examples of C1-C10 alkoxy groups mentioned in this invention include methoxy, ethoxy, butoxy, hexoxy, and octoxy.

[0064] Examples of C1-C10 thioalkoxy groups mentioned in this invention include: methylthio, ethylthio, butylthio, hexylthio, octylthio, etc.

[0065] Examples of C1-C10 silanes mentioned in this invention include trimethylsilane, triethylsilane, etc.

[0066] Examples of C6-C30 arylamino groups mentioned in this invention include phenylamino, methylphenylamino, naphthylamino, anthraceneylamino, phenanthreneamino, and biphenylamino.

[0067] Examples of C3-C30 heteroaryl amino groups mentioned in this invention include pyridinyl amino, pyrimidinyl amino, and dibenzofuranyl amino.

[0068] The C6-C30 aryl groups mentioned in this invention include monocyclic aryl groups of C6-30 and fused-ring aryl groups of C10-C30. Examples of C6-30 monocyclic aryl groups include phenyl, biphenyl, and terphenyl. Specifically, the biphenyl group includes 2-biphenyl, 3-biphenyl, and 4-biphenyl; the terphenyl group includes p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, meta-terphenyl-4-yl, meta-terphenyl-3-yl, and meta-terphenyl-2-yl. Examples of C10-C30 fused-ring aryl groups include naphthyl, anthraceneyl, phenanthryl, indene, fluorenyl, fluoranyl, triphenylene, pyrene, perylene, etc. Naphthyl, 2-anthyl, and their derivative groups, etc. Specifically, the naphthyl group includes 1-naphthyl or 2-naphthyl; the anthraceneyl group is selected from 1-anthrayl, 2-anthrayl, and 9-anthrayl; the fluorenyl group is selected from 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl, and 9-fluorenyl; the pyreneyl group is selected from 1-pyrene, 2-pyrene, and 4-pyrene; and the 2-anthyl tetraphenyl group is selected from 1-anthyl tetraphenyl, 2-anthyl tetraphenyl, and 9-anthyl tetraphenyl. The fluorene derivative group is selected from 9,9-dimethylfluorenyl, 9,9-diethylfluorenyl, 9,9-dipropylfluorenyl, 9,9-dibutylfluorenyl, 9,9-dipentylfluorenyl, 9,9-dihexylfluorenyl, 9,9-diphenylfluorenyl, 9,9-dinaphthylfluorenyl, spirofluorenyl, and benzo[a]fluorenyl.

[0069] The C3-C30 heteroaryl groups mentioned in this invention include C3-C30 monocyclic heteroaryl groups and C6-C30 fused-ring heteroaryl groups. Examples of C3-C30 monocyclic heteroaryl groups include furanyl, thiophene, pyrrole, and pyridinyl. Examples of C6-C30 fused-ring heteroaryl groups include benzofuranyl, benzothiophene, isobenzofuranyl, indolyl, dibenzofuranyl, dibenzothiophene, carbazole, acridine, isobenzofuranyl, isobenzothiophene, acridine, pyridinyl, benzocarbazole, azacarbazole, phenothiazinyl, and phenothiazinyl.

[0070] Specific examples of aryl groups in this invention can be exemplified by removing one hydrogen atom from the aforementioned aryl examples to obtain a divalent group. Specific examples of heteroaryl groups in this invention can be exemplified by removing one hydrogen atom from the aforementioned heteroaryl examples to obtain a divalent group.

[0071] The aryl group in this invention can be exemplified by the monovalent group composed of the above-mentioned aryl and heteroaryl groups and oxygen.

[0072] Examples of C6-C30 arylamino groups mentioned in this invention include phenylamino, methylphenylamino, naphthylamino, anthraceneylamino, phenanthreneamino, and biphenylamino.

[0073] Examples of C3-C30 heteroaryl amino groups mentioned in this invention include pyridinyl amino, pyrimidinyl amino, and dibenzofuranyl amino.

[0074] The preferred embodiments of each group have been described above, and those skilled in the art can combine them without departing from the spirit of the present invention. Some sub-formulas of general formula (1) are given below as examples, but the compound structures of the present invention are not limited to these sub-formulas.

[0075]

[0076]

[0077] Further preferred,

[0078]

[0079]

[0080] Further preferred,

[0081]

[0082]

[0083]

[0084] In the above general formulas, Z 11 ~Z 18 Z 5’ ~Z 7’ With Z in the previous text 1 ~Z 4 Having the same range, R 8’ and R 8” R in the previous text 8 They have the same range.

[0085] Furthermore, the general formula compounds of the present invention are preferably the following specific compounds, but the present invention is not limited to the specific compounds shown below:

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095] As another aspect of the invention, the application of the compound described above in an organic electroluminescent device is also provided. Specifically, it is preferably used as a light-emitting layer material in an organic electroluminescent device.

[0096] As another aspect of the present invention, an organic electroluminescent device is also provided, comprising a first electrode, a second electrode and an organic layer inserted between the first electrode and the second electrode, characterized in that the organic layer contains a compound of general formula (1) as described above, or contains a compound of general formula (1-1) or (1-2) as described above.

[0097] Invention Effects

[0098] The compounds of general formula (1) of this invention have a suitable rigid conjugated structure as the parent nucleus. By connecting specific aromatic groups to the parent nucleus via methylene, imine, O, or S groups, the conjugated structure between the parent nucleus and these groups is broken. Therefore, they exhibit high external quantum efficiency and low on / off voltage in OLED devices. When the compounds obtained by connecting the specific parent nucleus and the specific aromatic groups in the above-described specific manner are used as emitting layer dyes, they can improve the voltage and efficiency of the device while avoiding redshift and improving color purity. The compounds obtained through the above scheme are very suitable for application in OLEDs, and the resulting devices exhibit excellent performance, meeting the requirements of users. Detailed Implementation

[0099] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention.

[0100] Synthesis Example 1: Synthesis of P1

[0101]

[0102] At room temperature, starter 1 (20 g, 88.54 mmol), starter 2 (58 g, 177.07 mmol), bis[di-tert-butyl-(4-dimethylaminophenyl)phosphine]palladium(II) dichloride (2.5 g, 3.54 mmol), sodium tert-butoxide (25.5 g, 265.61 mmol), and xylene (200 ml) were added to a 500 ml three-necked flask as solvent. Nitrogen gas was purged three times, and the mixture was heated to 120 °C and reacted for 12 h. Heating was then stopped, the mixture was filtered and evaporated to dryness, and purified by column chromatography (petroleum ether: dichloromethane = 10:1) to obtain 55.0 g of product (intermediate M1).

[0103] Intermediate M1 (55 g, 72.04 mmol) was dissolved in 500 mL xylene. Butyllithium (86.4 mL, 216.12 mmol) was slowly added dropwise at -40 °C. After the addition was complete, the mixture was allowed to return to room temperature and then activated at 50 °C for 2 h. The temperature was then lowered to -40 °C, and BBr3 (45.03 g, 180.1 mmol) and DIEA (37.2 g, 288.16 mmol) were slowly added sequentially. After returning to room temperature, the mixture was heated to 110 °C for 10 h. Heating was then stopped, and the mixture was washed with water, filtered, and evaporated to dryness. The product was purified by column chromatography (petroleum ether: dichloromethane = 10:1) to obtain 19.8 g of product (P1).

[0104] Synthesis Example (2): Synthesis of P16

[0105]

[0106] The synthesis method was similar to that of Synthesis Example 1, except that raw material 2 was replaced with an equivalent amount of raw material 3, yielding 56.6 g of product (intermediate M2). The synthesis method of P16 was similar to that of P1, ultimately yielding 19.8 g of product (P16).

[0107] Synthesis Example (3): Synthesis of P29

[0108]

[0109] The synthesis method was similar to that of Synthesis Example 1, except that raw material 1 was replaced with an equivalent amount of raw material 4, yielding 28.2 g of product (intermediate M3). The synthesis method of P29 was similar to that of P1, ultimately yielding 9.87 g of product (P29).

[0110] Synthesis Example (4): Synthesis of P53

[0111]

[0112] At room temperature, starter 1 (10 g, 44.27 mmol), starter 2 (14.45 g, 44.27 mmol), (DBA)3Pd2 (0.81 g, 0.88 mmol), tri-tert-butylphosphine tetrafluoroborate (0.51 g, 1.77 mmol), sodium tert-butoxide (10.62 g, 110.68 mmol), and toluene (100 ml) were added to a 500 ml three-necked flask as solvent. Nitrogen gas was purged three times, and the mixture was heated to reflux for 12 h. Heating was then stopped, the mixture was filtered and evaporated to dryness, and purified by column chromatography (petroleum ether: dichloromethane = 10:1) to obtain 15 g of product (intermediate M4).

[0113] At room temperature, intermediate M4 (15 g, 31.75 mmol), starting material 3 (5.4 g, 31.75 mmol), Pd132 (0.45 g, 0.64 mmol), sodium tert-butoxide (7.62 g, 79.4 mmol), and xylene (200 ml) were added to a 500 ml three-necked flask as solvent. Nitrogen gas was purged three times, and the mixture was heated to 120 °C and reacted for 12 h. Heating was then stopped, the mixture was filtered and evaporated to dryness, and purified by column chromatography (petroleum ether: dichloromethane = 10:1) to obtain 16.7 g of product (intermediate M5).

[0114] Intermediate M5 (16.7 g, 27.63 mmol) was dissolved in 200 mL xylene. Butyllithium (33.2 mL, 82.88 mmol) was slowly added dropwise at -40 °C. After the addition was complete, the mixture was allowed to return to room temperature and then activated at 50 °C for 2 h. The temperature was then lowered to -40 °C, and BBr3 (17.27 g, 69.1 mmol) and DIEA (14.26 g, 110.52 mmol) were slowly added sequentially. After returning to room temperature, the mixture was heated to 110 °C for 10 h. Heating was then stopped, and the mixture was washed with water, filtered, and evaporated to dryness. The product was purified by column chromatography (petroleum ether: dichloromethane = 20:1) to obtain 6.78 g of product (P53).

[0115] Synthesis Example (5): Synthesis of Material 54

[0116]

[0117] The synthesis method was similar to that of Synthesis Example 4, except that raw material 5 was replaced with an equivalent amount of raw material 6, yielding 11.3 g of product (intermediate M6). The synthesis method of P54 was similar to that of P53, ultimately yielding 4.6 g of product (P54).

[0118] Synthesis Example (6): Synthesis of P84

[0119]

[0120] At room temperature, intermediate M4 (10 g, 21.17 mmol), starting material 7 (5.96 g, 21.17 mmol), Pd132 (0.3 g, 0.42 mmol), sodium tert-butoxide (5.1 g, 52.93 mmol), and xylene (200 ml) were added to a 500 ml three-necked flask as solvent. Nitrogen gas was purged three times, and the mixture was heated to 120 °C and reacted for 12 h. Heating was then stopped, the mixture was filtered and evaporated to dryness, and purified by column chromatography (petroleum ether: dichloromethane = 10:1) to obtain 10.8 g of product (intermediate M7).

[0121] Intermediate M7 (10.8 g, 15.60 mmol) was dissolved in 100 mL xylene. Butyllithium (18.12 mL, 45.29 mmol) was slowly added dropwise at -40 °C. After the addition was complete, the mixture was allowed to return to room temperature and then activated at 50 °C for 2 h. The temperature was then lowered to -40 °C, and BBr3 (9.75 g, 39 mmol) and DIEA (8.04 g, 62.4 mmol) were slowly added sequentially. After returning to room temperature, the mixture was heated to 110 °C for 10 h. Heating was then stopped, and the mixture was washed with water, filtered, evaporated to dryness, and purified by column chromatography (petroleum ether: dichloromethane = 10:1) to obtain 4.2 g of the product (P84).

[0122] Synthesis Example (7): Synthesis of P96

[0123]

[0124] At room temperature, starter 1 (10 g, 44.27 mmol), starter 3 (16.94 g, 44.27 mmol), (DBA)3Pd2 (0.81 g, 0.88 mmol), tri-tert-butylphosphine tetrafluoroborate (0.51 g, 1.77 mmol), sodium tert-butoxide (10.62 g, 110.68 mmol), and toluene (100 ml) were added to a 500 ml three-necked flask as solvent. Nitrogen gas was purged three times, and the mixture was heated to reflux for 12 h. Heating was then stopped, the mixture was filtered and evaporated to dryness, and purified by column chromatography (petroleum ether: dichloromethane = 10:1) to obtain 18.2 g of product (intermediate 8).

[0125] At room temperature, intermediate M8 (18.2 g, 34.43 mmol), starting material 7 (9.62 g, 34.43 mmol), Pd132 (0.49 g, 0.69 mmol), sodium tert-butoxide (8.26 g, 86.08 mmol), and xylene (200 ml) were added to a 500 ml three-necked flask as solvent. Nitrogen gas was purged three times, and the mixture was heated to 120 °C and reacted for 12 h. Heating was then stopped, the mixture was filtered and evaporated to dryness, and purified by column chromatography (petroleum ether: dichloromethane = 10:1) to obtain 19.56 g of product (intermediate M9).

[0126] Intermediate M9 (19.56 g, 37.01 mmol) was dissolved in 200 mL xylene. Butyllithium (44.41 mL, 111.03 mmol) was slowly added dropwise at -40 °C. After the addition was complete, the mixture was allowed to return to room temperature and then activated at 50 °C for 2 h. The temperature was then lowered to -40 °C, and BBr3 (23.13 g, 92.53 mmol) and DIEA (19.10 g, 148.04 mmol) were slowly added sequentially. After returning to room temperature, the mixture was heated to 110 °C for 10 h. Heating was then stopped, and the mixture was washed with water, filtered, evaporated to dryness, and purified by column chromatography (petroleum ether: dichloromethane = 20:1) to obtain 8.6 g of the product (P96).

[0127] Molecular structure theoretical calculations

[0128] This invention uses Gaussian O3 to perform quantum chemical calculations on the compounds. The time-dependent density functional method is used to perform theoretical calculations on P1, P16, P29, P53, P54, P84, P96 and C1, C2 respectively. The calculation results are shown in Table 1.

[0129] Table 1

[0130]

[0131]

[0132] The fluorescence emission wavelength of the material is related to the first singlet state energy level; the higher the energy level, the shorter the fluorescence emission wavelength and the more bluish the emission. The phosphorescence emission wavelength is related to the first triplet state energy level; the higher the energy level, the shorter the phosphorescence emission wavelength and the more bluish the emission. The photoluminescence efficiency of the material is related to the intensity of the first singlet oscillator; the higher the intensity of the first singlet oscillator, the higher the luminescence efficiency. Calculations show that the exciton energy level of material C1 is similar to that of the compound of this invention, but its first singlet oscillator intensity is relatively low, thus its luminescence efficiency may be relatively poor. The first singlet state energy level of C2 is lower than that of the compound of this invention, therefore its emission wavelength may be longer, which may not meet the requirements of deep blue light devices.

[0133] Device Examples

[0134] An OLED includes a first electrode and a second electrode, and an organic material layer located between the electrodes. This organic material layer can be further divided into multiple regions. For example, the organic material layer may include a hole transport region, a light-emitting layer, and an electron transport region.

[0135] In specific embodiments, a substrate can be used below the first electrode or above the second electrode. The substrate is typically made of glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. Furthermore, thin-film transistors (TFTs) can also be incorporated into the substrate used for displays.

[0136] The first electrode can be formed by sputtering or depositing the material to be used as the first electrode on a substrate. When the first electrode is used as the anode, it can be a transparent conductive oxide material such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO), or any combination thereof. When the first electrode is used as the cathode, it can be a metal or alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), ytterbium (Yb), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), or any combination thereof.

[0137] Organic material layers can be formed on electrodes using methods such as vacuum thermal evaporation, spin coating, and printing. The compounds used as organic material layers can be small organic molecules, large organic molecules, polymers, and combinations thereof.

[0138] The hole transport region is located between the anode and the emissive layer. The hole transport region can be a single-layer hole transport layer (HTL), including single-layer hole transport layers containing only one compound and single-layer hole transport layers containing multiple compounds. Alternatively, the hole transport region can be a multilayer structure including at least one of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL); wherein the HIL is located between the anode and the HTL, and the EBL is located between the HTL and the emissive layer.

[0139] The material for the hole transport region may be selected from, but is not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives as shown in HT-1 to HT-51 below; or any combination thereof.

[0140]

[0141]

[0142]

[0143] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can use one or more compounds from HT-1 to HT-51 described above, or one or more compounds from HI-1 to HI-3 described below; alternatively, one or more compounds from HT-1 to HT-51 can be used to dope one or more compounds from HI-1 to HI-3 described below.

[0144]

[0145] The emissive layer includes luminescent dyes (i.e., dopants) that can emit different wavelengths of light, and may also include a host material. The emissive layer can be a monochromatic emissive layer emitting a single color such as red, green, or blue. Multiple monochromatic emissive layers of different colors can be arranged in a planar pattern according to pixel design, or they can be stacked together to form a colored emissive layer. When different colored emissive layers are stacked together, they can be separated from each other or connected to each other. The emissive layer can also be a single colored emissive layer that can simultaneously emit different colors such as red, green, and blue.

[0146] Depending on the technology used, the light-emitting layer material can be various, including fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescence materials. An OLED device can employ a single light-emitting technology or a combination of different technologies. These different light-emitting materials, categorized by technology, can emit light of the same color or different colors.

[0147] In one aspect of the invention, the light-emitting layer employs fluorescent electroluminescence technology. The fluorescent host material of the light-emitting layer may be selected from, but is not limited to, one or more combinations of BFH-1 to BFH-17 listed below.

[0148]

[0149] In one aspect of the invention, the light-emitting layer employs thermally activated delayed fluorescence emission technology. The main material of the light-emitting layer is selected from, but not limited to, one or more combinations of PH-1 to PH-85 described above.

[0150]

[0151]

[0152]

[0153]

[0154] In one aspect of the invention, the light-emitting layer employs thermally activated delayed fluorescence emission technology. The fluorescent dopant in the light-emitting layer may be selected from, but not limited to, one or more combinations of TDE1-TDE37 listed below.

[0155]

[0156]

[0157] In one aspect of the present invention, an electron blocking layer (EBL) is located between the hole transport layer and the light-emitting layer. The electron blocking layer may employ, but is not limited to, one or more compounds of HT-1 to HT-51 described above, or one or more compounds of PH-47 to PH-77 described above; or a mixture of one or more compounds of HT-1 to HT-51 and one or more compounds of PH-47 to PH-77 may be employed.

[0158] The OLED organic material layer may also include an electron transport region between the light-emitting layer and the cathode. The electron transport region can be a single-layer electron transport layer (ETL), including single-layer electron transport layers containing only one compound and single-layer electron transport layers containing multiple compounds. Alternatively, the electron transport region can be a multilayer structure including at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0159] In one aspect of the present invention, the electron transport layer material may be selected from, but not limited to, one or more combinations of ET-1 to ET-65 listed below.

[0160]

[0161]

[0162]

[0163]

[0164] In one aspect of the present invention, a hole blocking layer (HBL) is located between the electron transport layer and the light-emitting layer. The hole blocking layer may employ, but is not limited to, one or more compounds of ET-1 to ET-65, or one or more compounds of PH-1 to PH-46; or a mixture of one or more compounds of ET-1 to ET-65 and one or more compounds of PH-1 to PH-46 may be employed.

[0165] The device may also include an electron injection layer located between the electron transport layer and the cathode, and the electron injection layer material includes, but is not limited to, one or more combinations of the following.

[0166] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Mg, Yb.

[0167] The fabrication process of the organic electroluminescent device in this embodiment is as follows:

[0168] Example 1

[0169] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a acetone:ethanol mixed solvent, baked in a clean environment until all moisture was removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0170] The glass substrate with the anode was placed in a vacuum chamber and evacuated to a vacuum level of <1×10⁻⁶. -5 Pa, on the aforementioned anolyte film, a 10 nm HT-4:HI-3 (97 / 3, w / w) mixture was vacuum thermally deposited as a hole injection layer, a 60 nm HT-4 compound as a hole transport layer, and a 5 nm HT-14 compound as an electron blocking layer; a 20 nm BFH-4:P1 (100:3, w / w) binary mixture was deposited as a light-emitting layer, a 5 nm ET-23 compound as a hole blocking layer, a 25 nm ET-61:ET-57 (50 / 50, w / w) compound as an electron transport layer, a 1 nm LiF compound as an electron injection layer, and a 150 nm aluminum metal as a cathode. The total deposition rate of all organic layers and LiF was controlled at 0.1 nm / s, and the deposition rate of the metal electrode was controlled at 1 nm / s.

[0171] Examples 2-9 and Comparative Examples 1-2

[0172] Except that P1 in Example 1 was replaced with the corresponding compound in Table 2, the organic electroluminescent devices of Examples 2 to 9 and Comparative Examples 1 to 2 were obtained in the same manner as in Example 1.

[0173] The structural formulas of compounds C1 and C2 are as follows.

[0174]

[0175] The organic electroluminescent devices prepared by the above process were subjected to the following performance measurements:

[0176] At the same brightness, the driving voltage and external quantum efficiency (EQE) of the organic electroluminescent devices prepared in Examples 1-9 and Comparative Examples 1-2 were measured using a digital source meter and a luminance meter. Specifically, the voltage was increased at a rate of 0.1 V per second, and the driving voltage and external quantum efficiency (EQE) were measured when the brightness of the organic electroluminescent device reached 1000 cd / m². 2 The voltage at that time is the driving voltage, and the external quantum efficiency at that time is also measured.

[0177] Table 2: Comparison of device performance when the compounds of this invention and those of existing technologies are used as hole transport materials.

[0178] Device Implementation Example Number Compound numbering Voltage V EQE (%) Light color Comparative Example 1 C1 5.4 5.5 Deep blue light Comparative Example 2 C2 5.2 6.8 Sky blue light Example 1 P1 4.7 6.9 Deep blue light Example 2 P16 4.5 6.7 Deep blue light Example 3 P29 4.9 6.2 Deep blue light Example 4 P36 4.5 6.7 Deep blue light Example 5 P44 4.3 6.9 Deep blue light Example 6 P53 4.4 6.5 Deep blue light Example 7 P54 4.8 6.5 Deep blue light Example 8 P84 4.5 6.5 Deep blue light Example 9 P96 4.7 6.6 Deep blue light Example 10 P155 4.5 6.8 Deep blue light Example 11 P159 4.5 6.6 Deep blue light Example 12 P181 4.8 6.4 Deep blue light Example 13 P182 4.6 6.6 Deep blue light Example 14 P183 4.2 6.7 Deep blue light Example 15 P184 4.5 6.3 Deep blue light Example 17 P186 4.3 6.3 Deep blue light Example 18 P187 4.9 6.4 Deep blue light Example 19 P188 4.8 6.0 Deep blue light Example 20 P189 5.0 6.2 Deep blue light Example 21 P190 4.8 5.9 Deep blue light Example 22 P191 4.9 6.0 Deep blue light Example 23 P192 4.9 6.1 Deep blue light

[0179] The above results indicate that, compared to reference material C1, the BN-type organic materials of this invention, when used in organic electroluminescent devices, exhibit higher external quantum efficiency and lower voltage due to their rigid structure and better carrier transport performance. Compared to reference material C2, the BN-type organic materials of this invention produce a more bluish light color in organic electroluminescent devices. It is speculated that this is because C2 lacks the group shown in formula (1) of the compound of this invention; therefore, when used in organic electroluminescent devices, it emits sky-blue light (470nm-490nm) instead of deep blue light.

[0180] The organic electroluminescent devices of Examples 12-15 exhibited better performance than Comparative Example 1, but were slightly inferior to Example 1. Specifically, the emitting layer dye of the organic electroluminescent device of Example 1 used compound P1 of the present invention, whose X... 1 and X 2 All are NR 3 The organic electroluminescent devices in Examples 12-15 use compounds P181-P184, whose X 1 and X 2 CR 1 R 2 O, S and SiR 4 R 5 From the above results, it can be seen that, in terms of the external quantum efficiency of the device, Example 1 using P1 > Example 13 using P182 ≈ Example 14 using P183 > Example 12 using P181 ≈ Example 15 using P184. This may be because the compound of general formula (1) of the present invention, obtained by connecting a specific aromatic group to the parent nucleus with an imine group while breaking the conjugated structure between the parent nucleus and the group, has a relatively high first singlet oscillator strength, thus exhibiting a higher external quantum efficiency.

[0181] Although the invention has been described in conjunction with embodiments, the invention is not limited to the above embodiments. It should be understood that various modifications and improvements can be made by those skilled in the art under the guidance of the inventive concept, and the appended claims summarize the scope of the invention.

Claims

1. An organic compound, characterized in that, It has the structure shown in equations (1-3) and (1-4): in, X 1 and X 2 Each independently selected from CR 1 R 2 NR 3 O, S or SiR 4 R 5 One of them; Ring G is a substituted or unsubstituted C5-C10 aromatic ring, and the substituted or unsubstituted C3-C10 contains one of the N-containing aromatic heterocycles. R 1 R 2 It is independently selected from one of C3-C10 cycloalkyl, C1-C10 chain alkyl substituted or unsubstituted phenyl or biphenyl; R 3 It is selected from one of C3~C10 cycloalkyl, C1~C10 alkoxy, C1~C10 chain alkyl substituted or unsubstituted phenyl or biphenyl, pyridyl; R 4 R 5 Selected from methyl or phenyl; Y 1 and Y 2 Each independently selected from CR 6 R 7 One of O, or S; R 6 R 7 It is independently selected from one of halogen, cyano, amino, and C1-C10 chain alkyl groups; Z 1 Z 4 Z 1‘ Z 4‘ Z 5 Z 7 Each is independently represented by CH; Z 5’ ~Z 7’ CR independently 12’ The R 12’ Each is independently selected from hydrogen or methyl; Z 6 Z 8 CR independently 12 The R 12 Each is independently selected from hydrogen or one of the following groups: When the above groups contain substituents, the substituents are selected from one or a combination of at least two of halogens, cyano groups, C1-C10 chain alkyl groups, C3-C10 cycloalkyl groups, and C1-C10 alkoxy groups.

2. An organic compound, characterized in that, It has a structure as shown in equation (1-9): （1-9） in, Ring G is a substituted or unsubstituted C5-C10 aromatic ring, and the substituted or unsubstituted C3-C10 contains one of the N-containing aromatic heterocycles. Y 1 and Y 2 Each independently selected from CR 6 R 7 One of them; R 6 R 7 Independently selected from one of the C1-C10 chain alkyl groups; Z 1 Z 4 Z 5 Z 7 Each is independently represented by CH; Z 5’ ~Z 7’ Each is independently represented by CH; Z 6 Z 11 ~Z 14 CR independently 12 The R 12 Each is independently selected from hydrogen or one of the following groups: When the above groups contain substituents, the substituents are selected from one or a combination of at least two of halogens, cyano groups, C1-C10 chain alkyl groups, C3-C10 cycloalkyl groups, and C1-C10 alkoxy groups.

3. The organic compound according to claim 1, characterized in that, X 1 and X 2 Each independently selected from NR 3 One of O or S.

4. The organic compound according to claim 1, characterized in that, Y 1 and Y 2 At least one is a CR 6 R 7 .

5. Organic compounds having the following structures: 。 6. The use of the organic compound according to any one of claims 1 to 5 as a light-emitting layer material in an organic electroluminescent device.

7. An organic electroluminescent device, comprising a first electrode, a second electrode, and an organic layer inserted between the first electrode and the second electrode, characterized in that, The organic layer contains any one of the organic compounds according to claims 1 to 5.

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