Organic Semiconductor Materials Containing Octa-Aza Condensed Rings, Preparation Methods Thereof and Applications

Abstract

The present invention discloses an organic semiconductor material containing an eight-membered nitrogen heterocyclic ring, a preparation method thereof, and applications thereof. The structural formula of the organic semiconductor material containing an eight-membered nitrogen heterocyclic ring of the present invention is Formula (I) - Formula (IX). The organic semiconductor material containing an eight-membered nitrogen heterocyclic ring of the present invention can be used as a light-emitting material in an organic light-emitting diode, and has the characteristics of efficient deep blue light emission and narrow full width at half maximum, thereby obtaining an organic electroluminescent device with excellent optoelectronic properties, and finally realizing the application of organic electroluminescence in the field of ultra-high definition display.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic optoelectronic materials, and particularly relates to an organic semiconductor material containing an eight-membered nitrogen heterocyclic ring, a preparation method thereof, and an application thereof. Background Art

[0002] With the continuous progress of display technology, especially the increasing demands in the fields of ultra-high definition, wide color gamut, and high resolution, higher requirements are put forward for the color performance of display devices such as OLEDs. In application scenarios with extremely high requirements for display effects, such as augmented reality, virtual reality, and wearable display devices, OLED screens need to have more excellent color purity and display performance. Therefore, there is an urgent need to develop new high-performance organic semiconductor materials with narrow-band emission characteristics.

[0003] However, different from the "narrow line" characteristics presented by atomic spectra, due to the relative vibrational energy between atoms and the vibrational and rotational energy of the whole molecule in the molecule, its spectrum mostly presents the characteristics of a "band". Therefore, traditional molecular design strategies are difficult to achieve ideal color purity and difficult to achieve ideal display effects. In recent years, through innovative molecular design and structural regulation, researchers have tried to narrow the emission bandwidth and improve color purity through multiple resonance effects and modification means, but still face problems such as a single luminescent backbone structure and fewer modifiable sites. Therefore, designing and developing new organic semiconductor materials with narrow-band emission and high color purity has become an important topic for the further development of OLED technology. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide an organic semiconductor material containing an eight-membered nitrogen heterocyclic ring; the organic semiconductor material containing an eight-membered nitrogen heterocyclic ring provided by the present invention has narrow-band emission characteristics and high color purity. The luminescent backbone of this material adopts a unique eight-membered nitrogen heterocyclic ring structure, which not only has high rigidity but also has multiple modifiable sites, facilitating fine regulation of the molecular structure to optimize its optical properties. By reasonably designing the structure of the eight-membered ring, this material can achieve a relatively narrow spectral bandwidth, thereby effectively improving the color purity and display performance of OLED devices. Based on the fact that this type of organic semiconductor material has high solid-state luminescence efficiency, narrow-band emission, and adjustable color performance, it can meet the requirements of high-color-purity OLED display devices and provides important technical support for future high-end display technologies.

[0005] Another object of the present invention is to provide a preparation method of the above-mentioned organic semiconductor material containing an eight-membered nitrogen heterocyclic ring. The preparation method of the present invention has simple process, easily available raw materials, and high yield.

[0006] Another object of the present invention is to provide the application of the above-mentioned organic semiconductor material containing an eight-membered nitrogen heterocyclic ring in the field of organic electroluminescence, especially in the preparation of the light-emitting layer of an organic light-emitting diode.

[0007] The object of the present invention is achieved by at least one of the following technical solutions.

[0008] An organic semiconductor material containing an eight-membered nitrogen heterocyclic ring provided by the present invention has the following structural formula:

[0009]

[0010] Wherein, each Z is independently C-R1 or N, and each R1 is independently selected from a hydrogen atom, a deuterium atom, a tritium atom, a halogen atom, an aldehyde group, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C1-C20 heteroalkyl group, a substituted or unsubstituted C3-C60 cycloalkyl group, a substituted or unsubstituted C2-C60 heterocycloalkyl group, a substituted or unsubstituted C1-C40 alkoxy group, a substituted or unsubstituted C1-C40 heteroalkoxy group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C2-C60 heteroaryl group, a substituted or unsubstituted C6-C60 aryloxy group, a substituted or unsubstituted C2-C60 heteroaryloxy group, a substituted or unsubstituted C1-C40 alkylamino group, a substituted or unsubstituted C1-C40 heteroalkylamino group, a substituted or unsubstituted C6-C60 arylamino group, a substituted or unsubstituted C2-C60 heteroarylamino group, a substituted or unsubstituted B1-B20 boranyl group, a substituted or unsubstituted Si1-Si20 silyl group, a substituted or unsubstituted C6-C60 aromatic silyl group, and adjacent R1s are connected to form a ring or not connected;

[0011] The substituents in the substituted C1-C20 alkyl group, the substituted C1-C20 heteroalkyl group, the substituted C3-C60 cycloalkyl group, the substituted C2-C60 heterocycloalkyl group, the substituted C1-C40 alkoxy group, the substituted C1-C40 heteroalkoxy group, the substituted C6-C60 aryl group, the substituted C2-C60 heteroaryl group, the substituted C6-C60 aryloxy group, the substituted C2-C60 heteroaryloxy group, the substituted C1-C40 alkylamino group, the substituted C1-C40 heteroalkylamino group, the substituted C6-C60 arylamino group, the substituted C2-C60 heteroarylamino group, the substituted B1-B20 boranyl group, the substituted Si1-Si20 silyl group, and the substituted C6-C60 aromatic silyl group are each independently selected from one or more of a halogen atom, a cyano group, a nitro group, a carboxyl group, a sulfonic acid group, an aldehyde group, a C2-C10 acyl group, a C1-C10 alkyl group, a C3-C10 cycloalkyl group, a C1-C10 alkoxy group, a C6-C30 aryl group, a C6-C30 aryloxy group, a C2-C30 heteroaryl group, and an amino group;

[0012] V is carbon-R2R3, nitrogen-R4, silicon-R5R6, boron-R7, oxygen, sulfur or selenium;

[0013] W is carbon-R2R3, nitrogen-R4, silicon-R5R6, boron-R7, oxygen, sulfur or selenium;

[0014] X is a single bond, carbon-R2R3, nitrogen-R4, silicon-R5R6, boron-R7, oxygen, sulfur or selenium;

[0015] Y is a single bond, carbon-R2R3, nitrogen-R4, silicon-R5R6, boron-R7, oxygen, sulfur or selenium;

[0016] R2, R3, R4, R5, R6 and R7 are each independently selected from a hydrogen atom, a deuterium atom, a tritium atom, a halogen atom, an aldehyde group, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C2-C40 alkenyl group, a substituted or unsubstituted C1-C40 alkoxy group, a substituted or unsubstituted C3-C60 cycloalkyl group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C1-C40 alkylamino group, a substituted or unsubstituted C6-C60 arylamino group, a substituted or unsubstituted C2-C60 heteroarylamino group, a substituted or unsubstituted C2-C60 heterocycloalkyl group, R2 and R3 may or may not be linked to form a ring, and R5 and R6 may or may not be linked to form a ring;

[0017] The substituents in the substituted C1-C20 alkyl group, the substituted C2-C40 alkenyl group, the substituted C1-C40 alkoxy group, the substituted C3-C60 cycloalkyl group, the substituted C6-C60 aryl group, the substituted C1-C40 alkylamino group, the substituted C6-C60 arylamino group, the substituted C2-C60 heteroarylamino group, and the substituted C2-C60 heterocycloalkyl group are each independently selected from one or more of a halogen atom, a cyano group, a nitro group, a carboxyl group, a sulfonic acid group, an aldehyde group, a C2-C10 acyl group, a C1-C10 alkyl group, a C3-C10 cycloalkyl group, a C1-C10 alkoxy group, a C6-C30 aryl group, a C6-C30 aryloxy group, a C2-C30 heteroaryl group, and an amino group;

[0018] When the adjacent Z to V, W, X, Y is C-R1, R2, R3, R4, R5, R6, or R7 and R1 may or may not be linked to form a ring.

[0019] In the present invention, the term "substituted" means that a hydrogen atom bonded to a carbon atom of a compound is changed to another substituent, and there is no limitation on the substitution position as long as it is a position where the hydrogen atom is substituted, i.e., a position where the substituent can substitute; "substituted" means being substituted by one, two or more substituents, and when two or more substituents substitute, the two or more substituents may be the same or different from each other.

[0020] In the present invention, the alkyl group may be linear or branched, and preferably has 1 to 20 carbon atoms (such as 1, 3, 5, 10, 20, etc.). Specific examples of the alkyl group may include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, nonyl, 2,2-di-methylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 4-methylhexyl, 5-methylhexyl, etc., but are not limited thereto.

[0021] In the present invention, the alkenyl group may be linear or branched, and preferably has 2 to 40 carbon atoms (such as 2, 4, 6, 10, 20, 30, 40, etc.). Specific examples thereof may include vinyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 3-methyl-1-butenyl, 1,3-butadienyl, allyl, 1-phenylethenyl-1-yl, 2-phenylethenyl-1-yl, 2,2-diphenylethenyl-1-yl, 2-phenyl-2-(naphthalen-1-yl)ethenyl-1-yl, 2,2-bis(diphenyl-1-yl)ethenyl 1-yl, etc., but are not limited thereto.

[0022] In the present invention, the alkoxy group may be linear or branched. The alkoxy group preferably has 1 to 40 carbon atoms (such as 1, 3, 5, 10, 20, 30, 40, etc.). Specific examples thereof may include methoxy, ethoxy, n-propoxy, isopropoxy, isopropyloxy, n-butoxy, isobutoxy, tert-butoxy, sec-butoxy, n-pentyloxy, neopentyloxy, isopentyloxy, n-hexyloxy, 3,3-dimethylbutoxy, 2-ethylbutoxy, n-octyloxy, n-nonyloxy, n-decyloxy, etc., but are not limited thereto.

[0023] The alkyl groups, alkoxy groups and other substituents containing an alkyl moiety described in the present invention include both linear and branched forms.

[0024] In the present invention, the cycloalkyl group preferably has 3 to 60 carbon atoms, and according to one embodiment, the cycloalkyl group has 3 to 40 carbon atoms. According to another embodiment, the cycloalkyl group has 3 to 20 carbon atoms. According to another embodiment, the cycloalkyl group has 3 to 6 carbon atoms. Specific examples thereof may include cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl, etc., but are not limited thereto.

[0025] In the present invention, the alkylamino group preferably has 1 to 40 (1, 3, 5, 10, 20, 30, 40, etc.) carbon atoms, and specific examples of the alkylamino group may include methylamino, dimethylamino, ethylamino, diethylamino, etc., but are not limited thereto.

[0026] In the present invention, examples of the arylamino group include substituted or unsubstituted monoarylamino groups, substituted or unsubstituted diarylamino groups, or substituted or unsubstituted triarylamino groups. The aryl group in the arylamino group may be a monocyclic aryl group or a polycyclic aryl group. The arylamino group containing two or more aryl groups may contain a monocyclic aryl group, a polycyclic aryl group, or both a monocyclic aryl group and a polycyclic aryl group. Specific examples of the arylamino group may include aniline, naphthylamine, benzidine, anthrylamine, 3-methyl-aniline, 4-methyl-naphthylamine, 2-methyl-benzidine, 9-methyl-anthrylamine, diphenylamino, phenylnaphthylamino, xylarylamino, phenyltolylamino, carbazole, triphenylamino, etc., but are not limited thereto.

[0027] In the present invention, examples of the heteroarylamino group may include substituted or unsubstituted monoheteroarylamino groups, substituted or unsubstituted diheteroarylamino groups, or substituted or unsubstituted triheteroarylamino groups. The heteroaryl group in the heteroarylamino group may be a monocyclic heteroaryl group or a polycyclic heteroaryl group. The heteroarylamino group containing two or more heteroaryl groups may contain a monocyclic heteroaryl group, a polycyclic heteroaryl group, or both a monocyclic heteroaryl group and a polycyclic heteroaryl group.

[0028] In the present invention, the aryl group preferably has 6 to 60 carbon atoms (6, 10, 20, 30, 40, 50, 60, etc.), and may be a monocyclic aryl group or a polycyclic aryl group. When the aryl group is a monocyclic aryl group, examples thereof may include phenyl, biphenyl, terphenyl, etc., but are not limited thereto. Examples of the polycyclic aryl group may include naphthyl, anthryl, phenanthryl, pyrenyl, perylenyl, triphenyl, fluorenyl, etc., but are not limited thereto.

[0029] In the present invention, "adjacent" groups can mean any one or combination of the following two situations: (1) structurally adjacent, where the substituents are respectively connected to two directly bonded atoms, such as ortho-substituents on a benzene ring; (2) spatially adjacent, where the substituents are the closest in distance in a three-dimensional configuration, such as in the case where V, W, X, and Y are connected to form a ring, including but not limited to this case;

[0030] In the present invention, the "ring" in a substituted or unsubstituted ring formed by the bonding of adjacent groups to each other means a substituted or unsubstituted hydrocarbon ring; or a substituted or unsubstituted heterocyclic ring.

[0031] In the present invention, the hydrocarbon ring can be an aromatic ring, an aliphatic ring, or a fused ring of aromatic and aliphatic, and can be selected from examples of cycloalkyl or aryl, excluding non-monovalent cycloalkyl or aryl.

[0032] In the present invention, the description of aryl can be applied to an aromatic ring, except that the aromatic ring is monovalent.

[0033] In the present invention, the heterocyclic ring contains one or more non-carbon atoms, i.e., heteroatoms, and specifically, the heteroatoms can include one or more atoms selected from O, N, S, and Se. The heterocyclic ring can be a monocyclic or polycyclic aromatic ring, aliphatic ring, or a fused ring of aromatic and aliphatic, and can be selected from examples of heteroaryl, excluding non-monovalent heteroaryl.

[0034] Preferably, the structural formula of the organic semiconductor material containing an eight-membered nitrogen heterofused ring is as follows:

[0035]

[0036]

[0037]

[0038]

[0039]

[0040] The above-mentioned organic semiconductor material containing an eight-membered nitrogen heterofused ring is prepared by the following method. The substituents can be bonded using methods known in the art, and the type, position, or number of substituents can be changed according to techniques known in the art.

[0041] The present invention provides a preparation method of the above-mentioned organic semiconductor material containing an eight-membered nitrogen heterofused ring,

[0042] The preparation method of the compound shown in formula (I) includes the following steps:

[0043] (1) Compound 1 and Compound 2 undergo a carbon-carbon coupling reaction to obtain Compound 3;

[0044]

[0045] (2) The nucleophilic substitution reaction of compound 3 and compound 4 is carried out to construct an eight-membered ring, and compound 5 is obtained;

[0046]

[0047] (3) The nitro ring-closing reaction of compound 5 is achieved under the catalysis of triphenylphosphine to obtain the compound shown in formula (I);

[0048]

[0049] The preparation method of the compound shown in formula (II) comprises the following steps:

[0050] (4) The Buchwald-Hartwig coupling reaction of the secondary amine site of the compound shown in formula (I) and compound 6 is carried out to obtain the compound shown in formula (II);

[0051]

[0052] The preparation method of the compound shown in formula (III) comprises the following steps:

[0053] (5) The nucleophilic substitution reaction of the secondary amine site of compound 7 and compound 8 is carried out to obtain compound 9;

[0054]

[0055] (6) The cyclization reaction of compound 9 with a boron source, chlorosilanes, amines, ethers, sulfur or selenium is carried out, or a C-C bond is directly formed through the Scholl oxidative coupling reaction to obtain the compound shown in formula (III);

[0056]

[0057] The preparation method of the compound shown in formula (IV) comprises the following steps:

[0058] (7) The nucleophilic substitution reaction of the secondary amine site of compound 10 and compound 11 is carried out to obtain compound 12;

[0059]

[0060] (8) The cyclization reaction of compound 12 with a boron source, chlorosilanes, amines, ethers, sulfur or selenium is carried out, or a C-C bond is directly formed through the Scholl oxidative coupling reaction to obtain the compound shown in formula (IV);

[0061]

[0062] The preparation method of the compound shown in formula (V) comprises the following steps:

[0063] (9) Compound 13 and compound 14 undergo a carbon-carbon coupling reaction to obtain compound 15;

[0064]

[0065] (10) Compound 15 and compound 16 undergo a nucleophilic substitution reaction to construct an eight-membered ring, obtaining compound 17;

[0066]

[0067] (11) Compound 17 undergoes a nitro ring-closing reaction under the catalysis of triphenylphosphine to obtain compound 18;

[0068]

[0069] (12) Compound 18 undergoes a cyclization reaction with a boron source, a chlorosilane, ammonia, an ether, sulfur or selenium, or directly forms a C-C bond through a Scholl oxidative coupling reaction to obtain the compound shown in formula (V);

[0070]

[0071] The preparation method of the compound shown in formula (VI) comprises the following steps:

[0072] (13) The secondary amine site of compound 19 and compound 20 undergo a nucleophilic substitution reaction to obtain compound 21;

[0073]

[0074] (14) Compound 21 undergoes a cyclization reaction with a boron source, a chlorosilane, ammonia, an ether, sulfur or selenium, or directly forms a C-C bond through a Scholl oxidative coupling reaction to obtain the compound shown in formula (VI);

[0075] .

[0076] The preparation method of the compound shown in formula (VII) comprises the following steps:

[0077] (15) Compound 22 and compound 23 undergo a carbon-carbon coupling reaction to obtain compound 24;

[0078]

[0079] (16) Compound 24 and compound 25 undergo a nucleophilic substitution reaction to obtain compound 26;

[0080]

[0081] (17) Compound 26 undergoes a nitro ring-closing reaction under the catalysis of triphenylphosphine to obtain compound 27;

[0082]

[0083] (18) Compound 27 undergoes a cyclization reaction with a boron source, a chlorosilane, an ammonia, an ether, sulfur or selenium, or directly forms a C-C bond through a Scholl oxidative coupling reaction to obtain the compound shown in formula (VII);

[0084]

[0085] The preparation method of the compound shown in formula (VIII) comprises the following steps:

[0086] (19) The secondary amine site of the compound shown in formula (VII) undergoes a Buchwald-Hartwig coupling reaction with compound 6 to obtain the compound shown in formula (VIII);

[0087]

[0088] The preparation method of the compound shown in formula (IX) comprises the following steps:

[0089] (20) The secondary amine site of the compound shown in formula (V) undergoes a Buchwald-Hartwig coupling reaction with compound 6 to obtain the compound shown in formula (IX);

[0090]

[0091] Preferably, the temperature of the carbon-carbon coupling reaction in step (1) is 100-110 °C and the time is 8-12 h;

[0092] Preferably, the temperature of the nucleophilic substitution reaction in step (2) is 140-150 °C and the time is 4-8 h;

[0093] Preferably, the temperature of the nitro ring-closing reaction in step (3) is 150-180 °C and the time is 4-8 h.

[0094] Preferably, the temperature of the Buchwald-Hartwig coupling reaction in step (4) is 120-140 °C and the time is 4-8 h.

[0095] Preferably, the temperature of the nucleophilic substitution reaction in step (5) is 140-150 °C and the time is 4-8 h;

[0096] Preferably, the temperature of the cyclization reaction in step (6) is -40 to 210 °C, and the time is 24 to 48 h;

[0097] Preferably, the temperature of the nucleophilic substitution reaction in step (7) is 140 to 150 °C, and the time is 4 to 8 h;

[0098] Preferably, the temperature of the cyclization reaction in step (8) is -40 to 210 °C, and the time is 24 to 48 h.

[0099] Preferably, the temperature of the carbon-carbon coupling reaction in step (9) is 100 to 110 °C, and the time is 8 to 12 h.

[0100] Preferably, the temperature of the nucleophilic substitution reaction in step (10) is 140 to 150 °C, and the time is 4 to 8 h;

[0101] Preferably, the temperature of the nitro ring-closing reaction in step (11) is 150 to 180 °C, and the time is 4 to 8 h;

[0102] Preferably, the temperature of the cyclization reaction in step (12) is -40 to 210 °C, and the time is 24 to 48 h.

[0103] Preferably, the temperature of the nucleophilic substitution reaction in step (13) is 140 to 150 °C, and the time is 4 to 8 h;

[0104] Preferably, the temperature of the cyclization reaction in step (14) is -40 to 210 °C, and the time is 24 to 48 h.

[0105] Preferably, the temperature of the carbon-carbon coupling reaction in step (15) is 100 to 110 °C, and the time is 8 to 12 h;

[0106] Preferably, the temperature of the nucleophilic substitution reaction in step (16) is 140 to 150 °C, and the time is 4 to 8 h;

[0107] Preferably, the temperature of the nitro ring-closing reaction in step (17) is 150 to 180 °C, and the time is 4 to 8 h.

[0108] Preferably, the temperature of the cyclization reaction in step (18) is -40 to 210 °C, and the time is 24 to 48 h.

[0109] Preferably, the temperature of the Buchwald-Hartwig coupling reaction in step (19) is 120 to 140 °C, and the time is 4 to 8 h.

[0110] Preferably, the temperature of the Buchwald-Hartwig coupling reaction in step (20) is 120 to 140 °C, and the time is 4 to 8 h.

[0111] Preferably, the molar ratio of compound 1 to compound 2 in step (1) is 1:2 to 1:2.5.

[0112] Preferably, the molar ratio of compound 3 to compound 4 in step (2) is 1:1.5 to 1:2;

[0113] Preferably, the molar ratio of the compound represented by formula (I) to compound 6 in step (4) is 1:2 to 1:2.5.

[0114] Preferably, the molar ratio of compound 7 to compound 8 in step (5) is 1:1.5 to 1:2;

[0115] Preferably, the molar ratio of compound 10 to compound 11 in step (7) is 1:1.5 to 1:2;

[0116] Preferably, the molar ratio of compound 13 to compound 14 in step (9) is 1:2 to 1:2.5.

[0117] Preferably, the molar ratio of compound 15 to compound 16 in step (10) is 1:1.5 to 1:2;

[0118] Preferably, the molar ratio of compound 19 to compound 20 in step (13) is 1:1.5 to 1:2.

[0119] Preferably, the molar ratio of compound 22 to compound 23 in step (15) is 1:2 to 1:2.5.

[0120] Preferably, the molar ratio of compound 24 to compound 25 in step (16) is 1:1.5 to 1:2;

[0121] Preferably, the molar ratio of the compound represented by formula (VII) to compound 6 in step (19) is 1:2 to 1:2.5.

[0122] Preferably, the molar ratio of the compound represented by formula (V) to compound 6 in step (20) is 1:2 to 1:2.5.

[0123] The present invention provides an application of the above-mentioned organic semiconductor material containing an eight-membered nitrogen heterocyclic fused ring in the preparation of an organic electroluminescent device.

[0124] Preferably, the organic semiconductor material containing an eight-membered nitrogen heterocyclic fused ring is used as a light-emitting material.

[0125] The present invention selects an eight-membered nitrogen heterocyclic fused ring as the core building block, which is a luminescent building block with multiple resonance effects and has an excellent rigid backbone structure. It can effectively reduce the coupling effect between electrons and vibrations, thereby enabling spectral narrowing. At the same time, due to its simple preparation method, the synthesis raw materials of this building block have rich substrate expansion, thus realizing the diversification of modifiable sites.

[0126] In addition, and more importantly, the present invention discovers for the first time this new core building block, and the main peak position of the luminescence spectrum of its original backbone is in the deep blue light range, which indicates that it can be used as an excellent donor to construct an organic semiconductor material with a full spectrum. In addition, this type of material has thermally activated delayed fluorescence characteristics and can achieve high exciton utilization efficiency during the electroluminescence process. Therefore, based on such materials, highly efficient and high-color purity organic electroluminescent devices can be prepared. Moreover, the synthesis method of this type of material is efficient, and it has excellent thermal stability and electrochemical stability, enabling large-scale synthesis and purification of this type of material, and having broad application prospects in the field of organic electroluminescence.

[0127] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0128] (1) The organic semiconductor material containing an eight-membered nitrogen heterocyclic fused ring of the present invention simultaneously has a narrowed spectrum, high solid-state luminescence efficiency, and high exciton utilization efficiency, and can be used to prepare highly efficient and high-color purity organic electroluminescent devices.

[0129] (2) The synthesis method of the organic semiconductor material containing an eight-membered nitrogen heterocyclic fused ring of the present invention is simple, the raw materials are easy to obtain, the yield is relatively high, and the obtained material has a stable structure.

[0130] (3) The organic semiconductor material containing an eight-membered nitrogen heterocyclic fused ring of the present invention is used in the light-emitting layer of an organic light-emitting diode, and its comprehensive performance is excellent, and it can be widely used in fields such as organic electroluminescence. Description of the Drawings

[0131] Figure 1a It is the ultraviolet absorption spectrum and fluorescence emission spectrum of the 8NN compound in toluene solution in Example 4.

[0132] Figure 1b It is the ultraviolet absorption spectrum and fluorescence emission spectrum of the 8NNP compound in toluene solution in Example 4.

[0133] Figure 1c It is the ultraviolet absorption spectrum and fluorescence emission spectrum of the 8NNB compound in toluene solution in Example 4.

[0134] Figure 1d It is the fluorescence emission spectrum of the NDCZ compound in toluene solution in Comparative Example 1.

[0135] Figure 2a Electroluminescence spectrum of the doped OLEDs device prepared from the 8NNP compound in Example 5.

[0136] Figure 2b Graph of the efficiency versus luminance of the doped OLEDs device prepared from the 8NNP compound in Example 5.

[0137] Figure 2c J-V-L curve of the doped OLEDs device prepared from the 8NNP compound in Example 5.

[0138] Figure 3a Electroluminescence spectrum of the doped OLEDs device prepared from the 8NNB compound in Example 5.

[0139] Figure 3b Graph of the efficiency versus luminance of the doped OLEDs device prepared from the 8NNB compound in Example 5.

[0140] Figure 3c J-V-L curve of the doped OLEDs device prepared from the 8NNB compound in Example 5. Detailed implementation manners

[0141] The following further illustrates the specific implementation of the present invention in conjunction with examples, but the implementation and protection of the present invention are not limited thereto. It should be noted that for the processes not specifically described in detail below, those skilled in the art can implement or understand them with reference to the prior art. The reagents or instruments not indicating the manufacturer are regarded as conventional products that can be obtained through commercial purchase.

[0142] Example 1: Preparation of an organic semiconductor material (8NN) containing an eight-membered nitrogen heterocyclic fused ring:

[0143] The structural formula of 8NN is as follows:

[0144]

[0145] Reaction equation (1):

[0146]

[0147] (1)First, take a three-necked flask and weigh 2.19 g (10 mmol) of 2-bromo-3-fluoronitrobenzene, 2.1 g (15 mmol) of 2-fluorophenylboronic acid, 577.5 mg (0.5 mmol) of tetrakis(triphenylphosphine)palladium, and 11.04 g (80 mmol) of potassium carbonate and place them in the three-necked flask. Then, install the reaction device and seal it for evacuation. After evacuating for 10 minutes, introduce nitrogen gas into the device, and repeat this operation three times to remove all the air in the device. During the evacuation process, take a flask, use a syringe to draw 80 mL of N,N-dimethylformamide and 20 mL of deionized water and place them in the flask, and purge with nitrogen for 20 minutes to remove oxygen. After the oxygen is removed, use a syringe to inject the air-free solvent (80 mL of N,N-dimethylformamide and 20 mL of deionized water) into the three-necked flask, and heat the mixture to 150 °C under the protection of a nitrogen stream, with a rotor speed of 400 rpm and stir for 24 hours. After the reaction is completed, rotary evaporate the reaction system to remove the solvent, then extract with dichloromethane and deionized water, and after receiving the organic phase, powder the crude product, and separate and purify it by column chromatography. Rotary evaporate and filter the solution obtained by chromatography, and finally obtain the yellow powder (2.10 g) of N2F. 1 HNMR (400 MHz, CD2Cl2) δ 7.86 (d, J = 8.2 Hz, 1H), 7.58 (td, J = 8.3, 5.5 Hz, 1H),7.53 – 7.42 (m, 2H), 7.29 (ddt, J = 8.5, 7.6, 4.0 Hz, 2H), 7.24 – 7.16 (m, 1H).

[0148] (2)First, take a three-necked flask and weigh about 2.35 g (10 mmol) of the intermediate N2F, 3.84 g (15 mmol) of indolo[2,3-a]carbazole, and 5.76 g (30 mmol) of cesium carbonate and place them in the three-necked flask. Then, install the reaction device and seal it for evacuation. After evacuating for 10 minutes, introduce nitrogen into the device, and repeat this operation three times to remove all the air in the device. During the evacuation process, take a flask, place N,N-dimethylformamide in the flask, and purge it with nitrogen to remove oxygen. After the oxygen is completely removed, use a syringe to inject 50 mL of the degassed solvent (N,N-dimethylformamide) into the three-necked flask and stir for 20 minutes under the protection of a nitrogen stream. Then, heat the mixture to 150 °C, with a rotor speed of 400 rpm, and stir for 24 hours. After the reaction is completed, rotary evaporate the reaction system to remove the solvent, then extract with dichloromethane and deionized water, and after receiving the organic phase, powder the crude product. Separate and purify it by column chromatography. Rotary evaporate and filter the solution obtained by chromatography, and finally obtain 3.22 g of brown powder of NDCZ. 1 H NMR (500 MHz, CD2Cl2) δ 8.14 (dd, J J = 9.7, 3.7 Hz, 2H), 8.03 –7.94 (m, 2H), 7.79 (dd, J J = 8.0, 1.1 Hz, 1H), 7.68 (d, J J = 8.1 Hz, 1H), 7.54 (d, J J = 8.1 Hz, 1H), 7.51 – 7.31 (m, 8H), 7.27 (dd, J J = 8.3, 1.1 Hz, 1H), 7.03 (dd, J J =7.8, 1.4 Hz, 1H).

[0149] (3)First, prepare a flask, place o-dichlorobenzene in the flask, purge with nitrogen to remove oxygen, and withdraw 80 mL of o-dichlorobenzene with a syringe. At the same time, prepare a two-necked flask, weigh 4.52 g (10 mmol) of NDCZ and 7.86 g (30 mmol) of triphenylphosphine and place them in it. Install the reaction device and seal it for evacuation. After evacuating for 10 minutes, introduce nitrogen into the device and repeat the operation three times to remove all the air in the device. After the oxygen is removed, use a syringe to inject the air-free solvent (o-dichlorobenzene) into the two-necked flask, then raise the temperature to 180 °C under a nitrogen atmosphere, with a rotor speed of 400 rpm, and stir for 24 hours. After the reaction is completed, dilute the mixture with dichloromethane, wash it with water three times, then dry the diluted solution with MgSO4 for 15 minutes. After drying, perform rotary evaporation to remove the remaining solvent. Then pulverize the crude product and purify it by silica gel column chromatography. Evaporate the solution obtained by chromatography and filter it by suction. Finally, obtain the target product 8NN (1.50 g) as a pale yellow solid. 1 1H NMR (400 MHz, CD2Cl2) δ 8.62 (s, 1H), 8.21 (d, J J = 5.6 Hz, 2H), 8.18 (dd, J J = 6.2, 2.7 Hz, 2H), 7.59 – 7.54 (m, 2H), 7.52 – 7.40 (m, 6H), 7.35 – 7.28 (m, 4H).

[0150] Example 2: Preparation of an organic semiconductor material (8NNP) containing an eight-membered nitrogen heterocyclic ring:

[0151] The structural formula of 8NNP is as follows:

[0152]

[0153] Reaction equation (2):

[0154]

[0155] (1)The product 8NN of Example 1 is used in the Ullmann reaction to synthesize the final product 8NNP.

[0156] First, take a three-necked flask and weigh about 4.19 g (10 mmol) of the intermediate 8NN, 190.45 mg (1 mmol) of cuprous iodide, 115 mg (1 mmol) of L-proline, and 2.76 g (20 mmol) of potassium carbonate and place them in the three-necked flask. Then, install the reaction device and seal it for evacuation. After evacuating for 10 minutes, introduce nitrogen into the device, and repeat this operation three times to remove all the air in the device. During the evacuation process, take a flask, place dimethylsulfonamide in the flask, and purge with nitrogen to remove oxygen. After the oxygen is completely removed, use a syringe to inject 50 mL of air-free solvent (dimethyl sulfoxide) into the three-necked flask. Stir for 2 - 3 minutes under the protection of a nitrogen stream, and then add 7.80 g (50 mmol) of bromobenzene. Then heat the mixture to 195 °C, with a rotor speed of 400 rpm, and stir for 12 hours. After the reaction is completed, perform rotary evaporation on the reaction system to remove the solvent, then extract with dichloromethane and deionized water. After receiving the organic phase, powder the crude product, and separate and purify it by column chromatography. Rotate and evaporate the solution obtained by chromatography, and then perform suction filtration to finally obtain a white powder (4.55 g). Obtain a white solid of 8NNP with a yield of 92%. 1 H NMR (400MHz, THF) δ 8.23 (d, J = 6.8 Hz, 2H), 8.21 (dd, J = 5.9, 3.0 Hz, 2H), 7.75 (dt, J =15.2, 7.7 Hz, 4H), 7.60 (t, J = 7.2 Hz, 1H), 7.55 (dd, J = 5.8, 3.3 Hz, 2H), 7.47(t, J = 6.8 Hz, 4H), 7.35 – 7.31 (m, 2H), 7.28 (dd, J = 6.0, 3.0 Hz, 4H).

[0157] Example 3: Preparation of an organic semiconductor material (8NNB) containing an eight-membered nitrogen heterocyclic ring:

[0158] The structural formula of 8NNB is as follows:

[0159]

[0160] Reaction equation (III):

[0161]

[0162] (1) A mixture of compound 8NN (4.19 g, 10 mmol) and cesium carbonate (3.86 g, 20 mmol) was placed in a 100 mL round-bottom flask under nitrogen. Then, 25 mL of N,N-dimethylformamide (DMF) was injected into the flask, and the mixture was stirred at room temperature for 30 minutes. Then, o-bromofluorobenzene (8.75 g, 50 mmol) was injected into the reaction flask, and the mixture was stirred at 150 °C under a nitrogen atmosphere for 24 hours. When the reaction was cooled to room temperature, the mixture was poured into an aqueous solution and extracted several times with dichloromethane. The extract was dried over anhydrous MgSO4 and evaporated under reduced pressure to obtain a crude product, which was purified by silica gel column chromatography (petroleum ether / DCM, 4:1). A white solid of 8NNPBr was obtained in 62% yield. 1 H NMR (500 MHz, CD2Cl2) δ 8.26 – 8.18 (m, 4H), 7.98 (dd, J = 8.1, 1.2 Hz, 1H), 7.72 – 7.46 (m, 9H), 7.37 – 7.30 (m, 4H), 7.09 – 6.93 (m, 2H).

[0163] (2) Under nitrogen protection, 8NNPBr (1.72 g, 3 mmol) and 50 ml of ultra-dry tert-butylbenzene were added to a 125 ml three-necked round-bottom flask. The solution was cooled to -40 °C, and then a solution of n-butyllithium (2.2 ml, 2.50 M, 5.5 mmol) in n-hexane was added, and the mixture was stirred at 60 °C for 2 hours. After adding BBr3 (1.38 g, 5.5 mmol) at 0 °C, the temperature was raised to 150 °C and the reaction mixture was stirred for 12 hours. Then, the temperature was lowered to 0 °C, N,N-diisopropylethylamine (1.15 ml, 6.6 mmol) was added, and the reaction mixture was heated at 150 °C for 4 h. After cooling to 0 °C, magnesium trimethyl bromide (11 ml, 1.0 M, 11 mmol) dissolved in tetrahydrofuran was added, and the reaction mixture was stirred at room temperature for 12 hours. The solvent was removed under reduced pressure, the crude product was dissolved in dichloromethane, and washed with water and brine. The organic layer was dried over MgSO4, filtered, and the solvent was removed under reduced pressure. The product was purified by flash silica gel chromatography (10:1 petroleum ether:CH2Cl2 as the eluent) to obtain 1.18 g of a yellow solid 8NNB (yield 63%). 1 H NMR (400 MHz, CD2Cl2) δ 8.86 (d, J = 8.5 Hz, 1H), 8.62 – 8.47 (m, 1H), 8.32 – 8.10 (m, 4H), 8.08 – 7.87 (m, 3H), 7.70 (dd,J = 21.0, 6.1 Hz, 3H), 7.60–7.48 (m, 2H), 7.46 – 7.23 (m, 5H), 7.00 (d, J = 34.1 Hz, 2H), 2.41 (s, 3H),2.21 (s, 3H), 1.98 (s, 3H).

[0164] Example 4: Testing of the ultraviolet absorption and fluorescence emission spectra of the organic semiconductor material containing an eight-membered nitrogen heterocyclic ring

[0165] Weigh 2.08 mg of the 8NN compound and dissolve it in 5 mL of HPLC-grade toluene (TOL) to prepare a test sample with a concentration of 10 -3 mol / L. Take 30 μL of the 8NN test sample and add it to a 5 mL centrifuge tube, then add 2970 μL of pure HPLC-grade TOL. Stir evenly with an oscillator and transfer it to a quartz cuvette. At the same time, take another 3 mL of pure HPLC-grade TOL and place it in a quartz cuvette as a blank control group, and then immediately measure the ultraviolet absorption spectrum. Then take out the above experimental group quartz cuvette and put it into the fluorescence spectrometer; measure it at the corresponding maximum excitation wavelength. Finally, the ultraviolet absorption spectrum and fluorescence emission spectrum of the compound 8NN are obtained by processing the above data.

[0166] The testing methods of the ultraviolet absorption and fluorescence emission spectra of the 8NNP and 8NNB compounds are the same as above.

[0167] The ultraviolet absorption spectra and fluorescence emission spectra of the 8NN, 8NNP, and 8NNB compounds correspond to Figure 1a , Figure 1b and Figure 1c .

[0168] From Figure 1a it can be seen that above 380 nm in the ultraviolet absorption spectrum of the 8NN compound, there are obvious absorption peaks caused by the short-range charge transfer state (the maximum absorption peak is located at 398 nm); its emission spectrum in dilute toluene solution has obvious narrow emission properties, its main peak position is at 408 nm and the full width at half maximum is 19 nm. The values of its spectrum in the CIE 1931 color coordinates are (0.165, 0.011), and the extremely low CIE y value reflects the extremely high deep blue color purity characteristics. In addition, the fluorescence quantum efficiency of the single molecule state of this molecular solution is 27.3%.

[0169] From Figure 1bIt can be seen that above 390 nm in the ultraviolet absorption spectrum of the 8NNP compound, there are absorption peaks caused by an obvious short-range charge transfer state (the maximum absorption peak is located at 402 nm); at the same time, it has obvious deep blue light emission properties, with the main peak position at 411 nm and a narrow full width at half maximum of 17 nm in toluene solution. The luminescence efficiency of 8NNP in toluene solution is 33.6%. Compared with the emission spectrum of the 8NN compound, the peak position of 8NNP is similar to it, indicating that the introduction of the rotor structure of the peripheral benzene ring has little effect on the electronic structure of the molecular core skeleton, which retains the luminescence properties of the original skeleton. More importantly, the full width at half maximum of the emission spectrum of 8NNP in toluene solution is significantly narrowed to 17 nm, and the values of its spectrum in the CIE 1931 color coordinate are (0.163, 0.014), also reflecting the extremely high deep blue light color purity characteristics.

[0170] The molecule 8NNB is further cyclized from 8NNP to construct an organic semiconductor material with pure blue light emission and narrow band characteristics.

[0171] From Figure 1c It can be seen that above 420 nm in the ultraviolet absorption spectrum of the 8NNB compound, there are obvious absorption peaks caused by a short-range charge transfer state. Compared with 8NNP and 8NN, the maximum short-range absorption peak of 8NNB in dilute toluene solution is further red-shifted to 440 nm. At the same time, the introduction of boron atoms enhances the delocalization degree of the electron cloud, making the peak of its emission spectrum also red-shifted to the positive blue light range, with a peak value of 461 nm; its full width at half maximum also realizes the narrow band emission characteristics, which is 31 nm. The values of its spectrum in the CIE 1931 color coordinate are (0.131, 0.102), reflecting relatively high blue light color purity characteristics. To reduce the damage of harmful blue light to the human eye, the main peak of the blue light material for the blue light pixel points of display technology usually needs to be around 460 nm. The main peak of 8NNB formed after cyclization meets the actual requirements of display technology, and also reflects that the octa-nitrogen hetero-fused ring structure has good modifiability and can effectively realize the regulation of light color. The luminescence efficiency of 8NNB in toluene solution is 50.6%.

[0172] Based on the above, it is strongly proved that the multiple resonance skeleton of the octa-nitrogen hetero-fused ring structure can achieve narrow band emission characteristics, so as to obtain organic semiconductor materials with high color purity and realize the performance of organic semiconductor devices with high color purity.

[0173] Comparative Example 1: Testing of the fluorescence emission spectrum of the comparative molecule NDCZ compound

[0174] The testing method is the same as that in Example 4, and the fluorescence emission spectrum of the NDCZ compound is obtained by processing the data, corresponding to Figure 1d。The NDCZ compound is an intermediate before the buckle of the 8NN compound.

[0175] From Figure 1d It can be seen that, compared with the 8NN compound, the main emission peak of the precursor compound NDCZ in toluene solution is 388 nm, which is in the ultraviolet emission band. At the same time, it has a relatively wide full width at half maximum, which is 40 nm. In particular, an obvious shoulder peak appears at 475 nm in the spectrum, thus significantly reducing its color purity. The above results strongly prove that the eight-membered nitrogen heterocyclic fused aromatic hydrocarbon structure of this 8NN type can achieve good narrow emission characteristics with the support of 3 pyrrole-type N atoms, further proving the advantages of this type of structure in realizing high-color-purity organic semiconductor light-emitting materials.

[0176] Example 5: OLED device performance of organic semiconductor materials containing eight-membered nitrogen heterocycles

[0177] Using the organic semiconductor materials 8NNP and 8NNB containing eight-membered nitrogen heterocycles prepared in Examples 2 and 3 (the deep blue light wavelengths in the single-molecule solution state are 411 nm and 461 nm respectively, and the full width at half maximum is 17 nm and 31 nm) as the light-emitting materials, doped devices are prepared.

[0178] (1) Doped device structure of 8NNP compound: ITO / HATCN (5 nm) / TAPC (50 nm) / TCTA (5nm) / mcp (5 nm) / PPF: 3 wt% 8NNP (20 nm) / PPF (5 nm) / TmPyPB (30 nm) / LiF (1 nm) / Al (120 nm).

[0179] Among them, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HATCN), 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline] (TAPC), 4,4',4''-tris(carbazol-9-yl)triphenylamine (TCTA), 1,3,5-tris(3-pyridin-3-yl)phenyl (TmPyPB) and LiF are used as the hole injection layer, hole transport layer, exciton blocking layer, electron transport layer and electron injection layer respectively; 9,9'-(1,3-phenylene)di-9H-carbazole (mcp) and 2,8-bis(diphenylphosphoryl)dibenz[b,d]furan (PPF) are used as the electron blocking layer and hole blocking layer respectively. And the device performance is tested and characterized, and the results are shown in Figure 2a 、 Figure 2b and Figure 2c 。

[0180] Figure 2aThis is the electroluminescence spectrum of the doped OLEDs device prepared with 8NNP compound. As can be seen from the figure, the doped device based on 8NNP still retains the characteristics of photoluminescence in the single molecule state during the electroluminescence process, with a main peak of 418nm and a half-peak width of 18nm; the CIE color coordinates are (0.164, 0.023), showing excellent deep blue light color purity.

[0181] Figure 2b The efficiency of the doped OLEDs device prepared by the 8NNP compound changes with the brightness. It can be seen from the figure that the maximum external quantum efficiency of the doped device based on 8NNP is 2.52%.

[0182] Figure 2c The JVL curve of the doped OLEDs device prepared by 8NNP compound. It can be seen from the figure that the maximum brightness and start-up voltage of the doped device based on 8NNP are 264 cd / m 2 , 3.4 V.

[0183] (2) Doped device structure of 8NNB compound: ITO / HATCN (5 nm) / TAPC (50 nm) / TCTA (5 nm) / mcp (5 nm) / PPF: 3 wt% 8NNB (20 nm) / PPF (5 nm) / TmPyPB (30 nm) / LiF (1 nm) / Al (120 nm).

[0184] Among them, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HATCN), 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline] (TAPC), 4,4',4''-tri(carbazole-9-yl)triphenylamine (TCTA), 1,3,5-tri(3-pyridine-3-phenyl)benzene (TmPyPB) and LiF are used as hole injection layer, hole transport layer, exciton blocking layer, electron transport layer and electron injection layer respectively; 9,9'-(1,3-phenyl)di-9H-carbazole (mcp) and 2,8-bis(diphenylphosphoryl)dibenzo[B,D]furan (PPF) are used as electron blocking layer and hole blocking layer respectively. The device performance is tested and characterized, and the results are shown in Figure 3a , Figure 3b and Figure 3c .

[0185] Figure 3aElectroluminescence spectra of doped OLEDs devices prepared from 8NNB compounds. As can be seen from the figure, the full width at half maximum (FWHM) of the doped devices based on 8NNB is further broadened to 48 nm during electroluminescence, the main peak position is 476 nm, and the CIE coordinates are (0.131, 0.238). Although the borated structure is susceptible to the external polar field effect after doping, resulting in an increase in the peak width, the main peak position is in the range of positive blue light emission and still exhibits the characteristics of narrow-band emission.

[0186] Figure 3b Graph of the efficiency of doped OLEDs devices prepared from 8NNB compounds varying with brightness. As can be seen from the figure, the maximum external quantum efficiency of the doped devices based on 8NNB increases significantly to 20.01%.

[0187] Figure 3c J-V-L curve of doped OLEDs devices prepared from 8NNB compounds. As can be seen from the figure, compared with 8NNP, the doped devices based on 8NNB have a higher brightness, with a value of 4718 cd / m 2 , and the turn-on voltage is 3.4 V.

[0188] The above data show that the present invention takes the eight-membered nitrogen heterocyclic fused ring skeleton with multiple resonance characteristics as the core, which all exhibit excellent narrow-band emission characteristics during photoluminescence, and at the same time obtain organic semiconductor light-emitting devices with high color purity during electroluminescence. In particular, due to its simple preparation method, the synthetic raw materials of this building block have rich substrate expansion, thus realizing the diversification of modifiable sites, which indicates that it can be used as an excellent donor to construct organic semiconductor materials with a full spectrum. In addition, this type of material has thermally activated delayed fluorescence characteristics, breaking through the 25% exciton utilization rate limit of traditional fluorescent materials during electroluminescence, thereby further improving the exciton utilization rate. This type of material combines the characteristics of high solid-state luminescence efficiency, high electroluminescence exciton utilization rate, and narrow-band emission, and can be used to prepare highly efficient organic electroluminescent devices with high color purity.

[0189] Therefore, the organic electroluminescent devices prepared from this type of organic semiconductor materials have broad application prospects in the field of ultra-high definition displays.

[0190] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above embodiments. Any changes, substitutions, modifications, etc. made by those skilled in the art without departing from the spirit and essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. An organic semiconductor material containing an eight-membered nitrogen-fused ring, characterized in that: The structural formula is as follows: wherein each Z is independently C-R1 or N, and each R1 is independently selected from a hydrogen atom, a deuterium atom, a tritium atom, a halogen atom, an aldehyde group, and a C1-C20 alkyl group; X is boron-R7; R7 is selected from a hydrogen atom, a deuterium atom, a tritium atom, a halogen atom, an aldehyde group, a C1-C20 alkyl group, a C2-C40 alkenyl group, a C1-C40 alkoxy group, a C3-C60 cycloalkyl group, and a C6~C60 aryl group.

2. An organic semiconductor material containing an eight-membered nitrogen-fused ring, characterized in that: The structural formula is as follows: 。 3. The method for preparing an organic semiconductor material containing an eight-membered nitrogen-fused ring according to claim 1, characterized in that: The preparation method of the compound represented by formula (III) comprises the following steps: The secondary amine site of compound 7 undergoes a nucleophilic substitution reaction with compound 8 to obtain compound 9; Compound 9 undergoes a cyclization reaction with a boron source to obtain a compound represented by formula (III); 。 4. Use of the organic semiconductor material containing an eight-membered nitrogen-fused ring according to any one of claims 1 to 2 in the preparation of an organic electroluminescent device.

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