Benzocycloheptanone carbazole derivative as well as preparation method and application thereof

Abstract

The invention discloses benzocycloheptanone carbazole derivatives as well as a preparation method and application thereof, and belongs to the technical field of organic light-emitting materials and semiconductors. Benzocycloheptanone carbazole is used as a main body structure, and the main body structure belongs to a large rigid conjugated system, has relatively high chemical stability, proper singlet state, proper triplet state and proper molecular orbital energy level, and is an important unit for constructing an OLED luminescent layer material; when the main body structure is matched with an L1 substituent group (L1-1-L1-22), an L2 substituent group (L2-1-L2-43) or an L3 substituent group (L3-1-L3-89), a compound with obvious spatial stereoisomerism can be formed. Experiments prove that when the benzocycloheptanone carbazole derivative is applied to an OLED device as a luminescent layer material, the starting voltage can be effectively reduced, the luminescent property of the OLED device can be improved, and the service life of the OLED device can be prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic light-emitting materials and semiconductors, and particularly relates to benzocycloheptanone carbazole derivatives, a preparation method thereof, and applications thereof. Background Art

[0002] In recent years, organic light-emitting diodes (OLEDs; Organic Light-Emitting Diode) have become a popular research direction in the fields of lighting and display due to their excellent characteristics such as self-luminescence, high brightness, high contrast, transparency, wearability, foldability, low energy consumption, wide viewing angle, and low temperature resistance. A typical OLED device structure includes an anode layer, a hole injection layer (HIL; Hole Injection Layer), a hole transport layer (HTL; Hole Transport Layer), an electron blocking layer (EBL; Electron Blocking Layer), an emissive layer (EML; Emissive Layer), a hole blocking layer (HBL; Hole Blocking Layer), an electron transport layer (ETL; Electron Transport Layer), an electron injection layer (EIL; Electron Injection Layer), and a cathode layer. When a voltage is applied between the anode layer and the cathode layer, holes are injected from the anode and then move towards the EML via the HTL; at the same time, electrons are injected from the cathode and move towards the EML through the ETL. In the EML, electrons and holes recombine to form excitons, and the excitons transfer energy to the luminescent material, causing the luminescent material to emit light. The selection of the luminescent layer material has a significant impact on the current efficiency, driving voltage, emission color purity, emission brightness, and lifetime of OLED devices. Therefore, exploring luminescent layer materials with higher performance remains a key task in the current development of the OLED industry.

[0003] Chinese Patent Application No. CN112174874A, an organic compound and an organic optoelectronic device using the same, provides a compound that can be used as a functional layer material for organic electroluminescent devices. The compound has a matched HOMO energy level and triplet energy level, can limit the emission region of excitons in organic electroluminescent devices, improve the efficiency of organic electroluminescent devices, and reduce the voltage. However, the driving voltage of OLED devices prepared based on such compounds is not ideal.

[0004] The Chinese patent application with the publication number CN116444502, an organic light-emitting compound containing dibenzocycloheptanone, a preparation method and an application, provides an organic light-emitting compound containing dibenzocycloheptanone. Although this organic light-emitting compound has a low sublimation temperature and decomposition temperature, and the film morphology is stable, the conjugated length and emission color of the material can be regulated by changing the connected chemical structure, and the physical properties of the compound and the optoelectronic device performance based on it can be improved by changing the modifying groups on the aromatic structure. However, the lifespan of the OLED device prepared based on this type of organic light-emitting compound is not ideal.

[0005] Therefore, in order to meet people's higher requirements for OLED devices, it is urgent to develop light-emitting layer materials with higher performance. Summary of the Invention

[0006] In order to overcome the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide benzocycloheptanone-fused carbazole derivatives, a preparation method and an application thereof, so as to solve the technical problems that the driving voltage and service life of the existing light-emitting materials cannot meet the requirements.

[0007] In order to achieve the above purpose, the present invention adopts the following technical solutions: In the first aspect of the present invention, benzocycloheptanone-fused carbazole derivatives are disclosed, and the structure is shown in general formula I:

[0008] Among them, is the main structure; L is selected from substituted or unsubstituted C6~C 40 aryl, or selected from substituted or unsubstituted C4~C 40 heteroaryl; The bonding mode of L and the main structure is single-bond bonding.

[0009] Preferably, among the substituted or unsubstituted C4~C 40 heteroaryl, the heteroatoms are O, S, N or Si.

[0010] In the second aspect of the present invention, a preparation method of benzocycloheptanone-fused carbazole derivatives is disclosed, including the following steps: Step 1: Using 2-bromonitrobenzene and 2-aminophenylboronic acid pinacol ester as raw materials, through the suzuki coupling reaction, intermediate M1-1 is obtained; Step 2: Using intermediate M1-1 as the raw material, through the Sandmeyer reaction, intermediate M1-2 is obtained; Step 3: Using intermediate M1-2 as the raw material, through the [4+2] cycloaddition reaction, intermediate M1-3 is obtained; Step 4: Using intermediate M1-3 as a raw material, through a ring-closing reaction, intermediate M1 is obtained. Step 5: Using intermediate M1 and L-X as raw materials, through a nucleophilic substitution reaction, a benzocycloheptanone-fused carbazole derivative is obtained. In L-X, X is Cl or Br.

[0011] In the third aspect of the present invention, the application of the above-mentioned benzocycloheptanone-fused carbazole derivative in the preparation of an electroluminescent device is disclosed.

[0012] In the fourth aspect of the present invention, an electroluminescent device is disclosed, which includes an anode layer, a cathode layer, and a light-emitting layer located between the anode layer and the cathode layer. The material of the light-emitting layer is selected from one or more of the above-mentioned benzocycloheptanone-fused carbazole derivatives.

[0013] In the fifth aspect of the present invention, the application of the above-mentioned electroluminescent device in the fields of light-emitting illumination, image display, or optoelectronic signal transmission is disclosed.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The benzocycloheptanone-fused carbazole derivative provided by the present invention has a benzocycloheptanone-fused carbazole as the main structure. This main structure belongs to a large rigid conjugated system, has high chemical stability, and has appropriate singlet, triplet, and molecular orbital energy levels. It is an important unit for constructing the light-emitting layer material of OLEDs; when the main structure matches with the L1 substituent (L1-1 to L1-22), the L2 substituent (L2-1 to L2-43), or the L3 substituent (L3-1 to L3-89), a compound with obvious spatial stereoisomerism can be formed ( Figure 1 , taking L as 5-substituted phenanthrene as an example). Through experiments, it is proved that the benzocycloheptanone-fused carbazole derivative has strong electronegativity (C=O double bond) and rigidity, excellent luminescence performance, can be used as a light-emitting material to prepare the light-emitting layer of an OLED device, effectively reduce the turn-on voltage of the OLED device, improve the luminescence performance of the OLED device, and extend the service life of the OLED device.

[0015] Furthermore, when L is selected from the group L1-1 to L1-22, the benzocycloheptanone-fused carbazole derivative has a large conjugated π-electron system and can be used as a host light-emitting material to prepare the light-emitting layer of an OLED device.

[0016] Furthermore, when L is selected from the group L2-1 to L2-43, the benzocycloheptanone-fused carbazole derivative has a large conjugated π-electron system, which is beneficial to hole transport and luminescence. At the same time, it also contains an electron-donating group, which can improve the hole injection and transport ability, and can be used as a hole-transporting host light-emitting material to prepare the light-emitting layer of an OLED device.

[0017] Furthermore, when L is selected from the groups L3-1 to L3-89, the benzocycloheptanone-fused carbazole derivatives contain an electron-donating group and an electron-withdrawing group simultaneously, forming a D (Donate)-A (Accept) type molecule, which has the property of thermally activated delayed fluorescence (TADF) and can be used as a guest emitting material to prepare the emitting layer of an OLED device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a spatial stereoisomeric diagram of the benzocycloheptanone-fused carbazole derivative (L is 5-substituted phenanthrene) of the present invention and its main structure; Figure 2 It is a cross-sectional view of the organic electroluminescent device of the present invention; Figure 3 It is the NMR spectrum of the compound H1-14 of the present invention; Figure 4 It is the NMR spectrum of the compound H2-22 of the present invention; Figure 5 It is the NMR spectrum of the compound H3-23 of the present invention.

[0019] Description of the reference numerals: 1 - Substrate layer, 2 - Anode layer, 3 - Hole injection layer, 4 - Hole transport layer, 5 - Electron blocking layer, 6 - Emitting layer, 7 - Hole blocking layer, 8 - Electron transport layer, 9 - Electron injection layer, 10 - Cathode layer, 11 - Cover layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] To enable those skilled in the art to understand the features and effects of the present invention, the following is only a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein shall have the ordinary meaning understood by those skilled in the art for the present invention. When there is a conflict, the definition in this specification shall prevail. The theories or mechanisms described and disclosed herein, whether correct or not, shall not limit the scope of the present invention in any way, that is, the content of the present invention can be implemented without being limited by any specific theory or mechanism.

[0021] In this article, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are only for the sake of brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be regarded as having covered and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0022] In this article, unless otherwise specified, "D" in the structural formula represents "deuterium".

[0023] The present invention provides benzocycloheptanone-fused carbazole derivatives, the structure of which is shown in general formula I:

[0024] Among them, is the main structure; L is selected from substituted or unsubstituted aryl groups having 6 to 40 carbon atoms, or substituted or unsubstituted heteroaryl groups having 4 to 40 carbon atoms, and the heteroatoms in the heteroaryl groups include but are not limited to O, S, N or Si; The bonding mode of L to the main structure is single-bond bonding; Preferably, L is independently selected from any one of L1-1 to L1-22, L2-1 to L2-43 and L3-1 to L3-89, specifically as follows:

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036] ; In the above groups, " " represents the position where L can bond to the main structure; the groups L1-9, L1-10, L1-12, L1-13, L1-14, L1-16, L1-17, L1-18 and L1-22 are all bonded to the main structure through only one " " Bonding; The groups L2-4, L2-7, L2-8, L2-9, L2-10, L2-18, L2-19, L2-21, L2-24, L2-27, L2-28, L2-36, L2-38, L2-39, L2-40, L2-41, L2-42 and L2-43 are all bonded to the main structure only through a " "; Bonding; The groups L3-4, L3-5, L3-19, L3-45, L3-52, L3-61, L3-78, L3-79, L3-87 and L3-88 are all bonded to the main structure only through a " "; Bonding.

[0037] The present invention also provides a preparation method of the above benzocycloheptanone-fused carbazole derivative, comprising the following steps:

[0038] Step 1: Using 2-bromonitrobenzene and 2-aminophenylboronic acid pinacol ester as raw materials, through Suzuki coupling reaction, to obtain intermediate M1-1; Step 2: Using intermediate M1-1 as raw material, through Sandmeyer reaction, to obtain intermediate M1-2; Step 3: Using intermediate M1-2 as raw material, through [4+2] cycloaddition reaction, to obtain intermediate M1-3; Step 4: Using intermediate M1-3 as raw material, through ring closure reaction, to obtain intermediate M1; Step 5: Using intermediate M1 and L-X (i.e., compound l) as raw materials, through nucleophilic substitution reaction, to obtain the benzocycloheptanone-fused carbazole derivative; In L-X, L is independently selected from the groups L1-1~L1-22, L2-1~L2-43, L3-1~L3-89 and the corresponding derivatives, and X is Cl or Br.

[0039] Based on the above preparation method, the present invention synthesized the following compounds:

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065] 。

[0066] The present invention also provides an electroluminescent device, as Figure 2 shown, which sequentially includes a substrate layer 1, an anode layer 2, a hole injection layer 3, a hole transport layer 4, an electron blocking layer 5, a light-emitting layer 6, a hole blocking layer 7, an electron transport layer 8, an electron injection layer 9, a cathode layer 10, and a cover layer 11 from the anode to the cathode direction; the hole injection layer 3, the hole transport layer 4, the electron blocking layer 5, the light-emitting layer 6, the hole blocking layer 7, the electron transport layer 8, and the electron injection layer 9 together constitute a functional organic layer.

[0067] As the substrate layer 1, it is required to have high mechanical strength, excellent thermal stability, excellent waterproof property, and excellent transparency; As the anode layer 2, generally in order to enable holes to be smoothly injected into the functional organic layer, the material of the anode layer 2 is preferably a substance with a large work function. Specific examples of the material of the anode layer 2 that can be used include metals such as vanadium, chromium, copper, zinc, and gold, or their alloys; oxides such as zinc oxide, aluminum oxide, or tin dioxide; conductive polymers such as polypyrrole and polyaniline; The hole injection layer 3, hole transport layer 4, electron blocking layer 5, light-emitting layer 6, hole blocking layer 7, electron transport layer 8, and electron injection layer 9 together constitute the functional organic layer. The functional organic layer can be formed between the electrodes (anode layer 2 and cathode layer 10) by various means or methods such as vacuum thermal evaporation, spin coating, and printing. The hole injection layer 3, hole transport layer 4, electron blocking layer 5, hole blocking layer 7, electron transport layer 8, and electron injection layer 9 are prepared by using corresponding functional layer materials with excellent cost performance in the industry. The compatibility between the functional layers needs to be determined through a series of testing and screening processes; the compounds used as the functional organic layers other than the light-emitting layer 6 can be selected from organic small molecules, organic macromolecules, and polymers, as well as their combinations.

[0068] As the material of the hole injection layer 3, MoO3 is preferably used; As the material of the hole transport layer 4, one of the following materials can be selected: ; As the material of the electron blocking layer 5, one of the following materials can be selected: ; As the light-emitting layer 6, it is formed by co-evaporation of the host light-emitting material and the guest light-emitting material in a mass ratio of 98:2. The host light-emitting material is selected from any one of the compounds H1-1 to H1-28 and H2-1 to H2-56 of the present invention, and the guest light-emitting material used in combination is preferably ; or, the host light-emitting material is preferably , and the guest light-emitting material used in combination is selected from any one of the compounds H3-1 to H3-99 of the present invention.

[0069] As the material of the hole blocking layer 7, it is selected from one of them; As the material of the electron transport layer 8, one of the following materials is selected: ; As the cathode layer 10, generally in order to facilitate the injection of electrons into the functional organic layer, the material of the cathode layer 10 is preferably a substance with a small work function. Specific examples of the material that can be used as the cathode layer 10 include metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or their alloys, such as multi-layer structure substances like LiF-A1, LiO2-A1, Mg-Al, or Mg-Ag; As the cover layer 11, it can improve the refractive index of the surface of the cathode layer 10 and increase the light extraction rate; as the material of the cover layer 11, it is preferably .

[0070] The present invention also provides a method for preparing the above-mentioned electroluminescent device. After the substrate layer 1 is pretreated and cleaned, the anode layer 2 is adhered, and then the hole injection layer 3, hole transport layer 4, electron blocking layer 5, light-emitting layer 6, hole blocking layer 7, electron transport layer 8, and electron injection layer 9 with set thicknesses are sequentially evaporated. After that, the cathode layer 10 and the cover layer 11 are sputtered in a low-temperature environment, and finally, the electroluminescent device is fabricated by using conventional device testing and encapsulation means.

[0071] The electroluminescent device provided by the present invention can be applied in the fields of light-emitting illumination, image display, or optoelectronic signal transmission.

[0072] The following further elaborates the present invention in conjunction with specific embodiments. Those skilled in the art can refer to the preparation method of the general formula I compound, the preparation method of the intermediate M1 in Example 1, and the following specific embodiments to prepare compounds H1-1 to H1-28, H2-1 to H2-56, and H3-1 to H3-99. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content described in the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0073] The following embodiments use conventional instrument equipment in the art. For the experimental methods without specific conditions indicated in the following embodiments, they are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer. Various raw materials are used in the following embodiments. Unless otherwise stated, commercially available products are used, and their specifications are conventional specifications in the art.

[0074] Example 1 Synthesis of Compound H1-14 1. Synthesis of Intermediate M1:

[0075] Step 1: Under nitrogen protection, add 1.0 mol of 2-bromonitrobenzene, 1.0 mol of 2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline, 0.05 mol of tetrakis(triphenylphosphine)palladium, 1.0 mol of sodium bicarbonate, 1200 mL of 1,2-dimethoxyethane (DME), and 200 mL of water into a 3 L reaction flask and mix well. Then heat the reaction system to 90 °C and react for 12 h. After the reaction is completed, cool the reaction solution to room temperature and extract with ethyl acetate and water. The organic phase is dried with anhydrous magnesium sulfate, concentrated, and recrystallized. The obtained crude product is purified by silica gel column chromatography to obtain intermediate M1-1 (178 g, yield 83%). Liquid Chromatography-Mass Spectrometry (LC-MS) shows that the molecular weight is 215.1.

[0076] Step 2: Add 0.8 mol of intermediate M1-1, 800 mL of water, and 200 mL of concentrated hydrochloric acid into a 3 L reaction flask. Then heat the mixture solution to 60 °C until the mixture solution becomes clear. Then cool it to 5 °C, add 150 mL of an aqueous solution of sodium nitrite (0.88 mol) for diazotization, stir for 30 min, and then quickly add 150 mL of an aqueous solution of potassium iodide with a concentration of 3.2 mol / L. Then slowly heat to the boiling point and continue refluxing for 6 h. After the reaction is completed, cool the mixture to room temperature, add saturated sodium sulfate solution to quench the mixture, and adjust the pH value to 9 with saturated sodium hydroxide aqueous solution. Extract the mixture with ethyl acetate multiple times, combine the organic phases, dry the organic phase with anhydrous magnesium sulfate, and concentrate under reduced pressure. The obtained crude product is purified by silica gel column chromatography (ethyl acetate / petroleum ether) to obtain intermediate M1-2 (203 g, yield 78%). LC-MS shows that the molecular weight is 325.0.

[0077] Step 3: Under nitrogen protection, add 0.6 mol of intermediate M1-2, 0.9 mol of 2-(2-chlorophenyl)-2-oxoacetic acid, 0.03 mol of bis(dibenzylideneacetone)palladium, 1.8 mol of potassium phosphate, and 1.5 L of N,N-dimethylformamide (DMF) into a 3 L reaction flask. Start stirring, heat the reaction solution to 120 °C and react for 12 h until the reaction is complete. Then cool the reaction solution to room temperature, concentrate under reduced pressure to remove most of the solvent, add water and ethyl acetate for extraction. The organic phase is dried with anhydrous magnesium sulfate and concentrated. The obtained crude product is purified by silica gel column chromatography (ethyl acetate / petroleum ether) to obtain intermediate M1-3 (157 g, yield 78%). LC-MS shows that the molecular weight is 302.1.

[0078] Step 4: Under nitrogen protection, 0.5 mol of intermediate M1-3, 1.0 mol of triphenylphosphine and 1.2 L of 1,2-dichlorobenzene were successively added into a 5 L three-necked flask, and the mixture was stirred at 140 °C for 3 h until the reaction was complete. After the reaction, 1,2-dichlorobenzene was removed by concentration under reduced pressure, an appropriate amount of water and dichloromethane were added for extraction, the organic phase was dried over anhydrous MgSO4, filtered, concentrated, and the obtained crude product was purified by silica gel column chromatography (ethyl acetate / petroleum ether) to obtain intermediate M1, weighing 89 g, with a yield of 66%, an HPLC content of 98%, and LC-MS showing a molecular weight of 270.1.

[0079] 2. Synthesis of compound H1-14:

[0080] Under an inert atmosphere, 0.01 mol of intermediate M1, 0.0105 mol of 4-bromo-9,9-dimethylfluorene (l 1-15 ) and 50 mL of toluene were added to a 100 mL three-necked flask, and the mixture was stirred until the solution was clear. Then, 0.2 mmol of Pd2(dba)3, 0.5 mmol of Am-phos and 0.04 mmol of sodium tert-butoxide were added. After that, the reaction solution was heated to 120 °C and reacted for 10 h. After the reaction was completed, it was filtered through diatomaceous earth while hot, the filtrate was cooled to room temperature, purified water was added for washing, the organic phase was retained after liquid separation, and the aqueous phase was extracted with ethyl acetate. The organic phases were combined, dried over anhydrous magnesium sulfate, concentrated, and passed through a column (ethyl acetate / petroleum ether) to obtain compound H1-14, weighing 3.5 g, with a yield of 76%, a High Performance Liquid Chromatography (HPLC) content of 99%, LC-MS showing a molecular weight of 462.3, and the 1H NMR spectrum was as Figure 3 shown.

[0081] 1H NMR data of compound H1-14: 1 H NMR (500 MHz, CD3OH ) δ 8.58 (dd, J J = 14.8, 3.2 Hz, 1H), 8.34 (dd, J J = 14.7, 3.3 Hz, 1H), 7.94 – 7.56 (m, 7H), 7.54 – 7.08 (m, 8H), 1.69 (s, 6H).

[0082] Referring to the synthesis method of Reference Example 1, the raw materials reacting with intermediate M1 were correspondingly replaced with:

[0083]

[0084]

[0085]

[0086] , synthetic compounds H1-1 to H1-13, H1-15 to H1-28 were synthesized.

[0087] Example 2 Synthesis of compound H2-22

[0088] Referring to the synthesis process of reference compound H1-14, 0.01 mol of M1 and 0.0105 mol of 2-bromo-9,9'-spirobixanthene (l 2-30 ) were fed to obtain compound H2-22, with a weight of 4.4 g, a yield of 73%, an HPLC content of 99%, LC-MS showing a molecular weight of 600.3, and the 1H NMR spectrum as follows Figure 4 shown.

[0089] 1H NMR data of compound H2-22: 1 H NMR (500 MHz, CD3OH ) δ 8.58 (dd, J J = 7.5, 1.5 Hz, 1H), 8.34 (dd, J J = 7.4, 1.5 Hz, 1H), 7.87 (ddd, J J = 16.6, 7.5, 1.5 Hz, 3H), 7.73 (ddd, J J = 11.2, 7.3, 1.5 Hz, 4H), 7.62 (ddd, J J = 13.7, 7.5, 1.5 Hz, 2H), 7.50 (dd, J J = 7.0, 2.0 Hz, 1H), 7.42 – 7.08 (m, 12H), 7.00 (td, J J = 7.4, 1.5 Hz, 1H).

[0090] Referring to the synthesis method of Example 2, the raw materials reacting with intermediate M1 were correspondingly replaced with:

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098] , Compounds H2-1 to H2-21, H2-23 to H2-56 were synthesized.

[0099] Example 3 Synthesis of Compound H3-23

[0100] Referring to the synthesis process of reference compound H1-14, 0.01 mol of M1 and 0.0105 mol of 2-chloro-4,6-bis(2-naphthyl)-1,3,5-triazine (l 3-33 ) were charged to obtain Compound H3-23, with a weight of 4.3 g, a yield of 72%, an HPLC content of 99%, and LC-MS showing a molecular weight of 601.2. The 1H NMR spectrum is as Figure 5 shown.

[0101] 1H NMR data of Compound H3-23: 1 H NMR (500 MHz, CD3OH ) δ 9.09 (t, J J = 3.0Hz, 2H), 8.54 (ddd, J J = 23.1, 14.8, 3.1 Hz, 3H), 8.34 (dd, J J = 14.7, 3.3 Hz, 1H),8.23 – 7.95 (m, 6H), 7.85 (td, J J = 14.9, 3.2 Hz, 1H), 7.75 – 7.54 (m, 6H), 7.52– 7.45 (m, 1H), 7.43 – 7.06 (m, 4H).

[0102] Referring to the synthesis method of Example 3, the raw materials reacting with intermediate M1 were correspondingly replaced with:

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110] , Synthesize compound H3-1 to H3-22, H3-24 to H3-99.

[0111] Prepare the electroluminescent devices of Examples 4 to 33 and Comparative Examples 1 to 3 according to the structure information of the light-emitting layer 6 of the electroluminescent device given in Table 1.

[0112] Table 1 Structure of the light-emitting layer of the electroluminescent device

[0113] (Note: "Host:Dopant" refers to the mass ratio of the host light-emitting material and the guest light-emitting material.) Example 4 Electroluminescent device containing compound H1-1 An electroluminescent device containing compound H1-1, which sequentially includes polyethylene terephthalate (PET), indium tin oxide (ITO) conductive glass, MoO3, HT-2, EB-2, light-emitting layer 6, HB-1, ET-2, LiF, Al-Mg (Al:Mg = 9:1) and CPL from the anode to the cathode; wherein, the light-emitting layer 6 includes H1-1 and Ir(piq)3 with a mass ratio of 98:2.

[0114] The preparation method of the above-mentioned electroluminescent device containing compound H1-1 includes the following steps: Step 1, use 1.5 mm PET plastic as the substrate layer 1 and 0.15 mm ITO conductive glass as the anode layer 2, and wash them in turn by alkali washing, pure water washing, drying, and ultraviolet-ozone washing to remove the organic residues on the surfaces of the PET plastic and the ITO conductive glass.

[0115] Step 2, adhere a layer of ITO conductive glass on the PET plastic, use a vacuum evaporation device to evaporate 20 nm thick MoO3 as a hole injection layer 3, then evaporate 110 nm thick HT-2 as a hole transport layer 4, then evaporate 30 nm EB-2 as an electron blocking layer 5, continue to evaporate 60 nm of the light-emitting layer 6 formed by the compound H1-1 and Ir(piq)3 with a mass ratio of 98:2 on EB-2, and then continue to evaporate 10 nm thick HB-1 on the light-emitting layer 6 as a hole blocking layer 7, then continue to evaporate 30 nm thick ET-2 as an electron transport layer 8, and then continue to evaporate 16 nm LiF as an electron injection layer 9 on the electron transport layer 8. After the electron injection layer 9 is evaporated, a 10 nm thick Al-Mg (Al:Mg=9:1) alloy is sputtered as a cathode layer 10 by low-temperature sputtering, and finally a 40 nm thick CPL is continued to be evaporated on the cathode layer 10 as a covering layer 11.

[0116] Step 3: vacuum-encapsulate MoO3, HT-2, EB-2, light-emitting layer 6, HB-1, ET-2 and LiF layer to obtain an electroluminescent device.

[0117] Embodiment 5 to Embodiment 18 The difference from Example 4 is that in the light-emitting layer 6, compounds H1-8, H1-9, H1-14, H1-21, H2-3, H2-5, H2-9, H2-14, H2-15, H2-22, H2-36, H2-42, H2-44 and H2-49 are selected as the main light-emitting materials of the light-emitting layer 6, respectively.

[0118] Embodiment 19 to Embodiment 33 The difference from Example 4 is that in the light-emitting layer 6, BH-1 is selected as the main light-emitting material of the light-emitting layer 6, and compounds H3-1, H3-9, H3-14, H3-23, H3-26, H3-35, H3-37, H3-45, H3-73, H3-74, H3-76, H3-89, H3-91, H3-94 and H3-99 are selected as the guest light-emitting materials of the light-emitting layer 6 respectively.

[0119] Comparative Example 1 The difference from Example 4 is that in the light-emitting layer 6, BH-1 is used as the main light-emitting material.

[0120] The structure of the electroluminescent device is: PET substrate / ITO / MoO3 (20 nm) / HT-2 (110 nm) / EB-2 (30 nm) / BH-1:Ir(piq)3 = 98:2 (60 nm) / HB-1 (10 nm) / ET-2 (30 nm) / LiF (16 nm) / Al:Mg = 9:1 (10 nm) / CPL (40 nm).

[0121] Comparative Example 2 The difference from Example 4 is that in the light-emitting layer 6, the in the Chinese patent application with the publication number CN112174874A is used as the host light-emitting material.

[0122] The structure of the electroluminescent device is: PET substrate / ITO / MoO3 (20 nm) / HT-2 (110 nm) / EB-2 (30 nm) / C80:Ir(piq)3 = 98:2 / HB-1 (10 nm) / ET-2 (30 nm) / LiF (16 nm) / Al:Mg = 9:1 (10 nm) / CPL (40 nm).

[0123] Comparative Example 3 The difference from Example 4 is that in the light-emitting layer 6, BH-1 is used as the host light-emitting material, and the in the Chinese patent application with the publication number CN116444502A is used as the guest light-emitting material.

[0124] The structure of the electroluminescent device is: PET substrate / ITO / MoO3 (20 nm) / HT-2 (110 nm) / EB-2 (30 nm) / BH-1:M7 = 98:2 (60 nm) / HB-1 (10 nm) / ET-2 (30 nm) / LiF (16 nm) / Al:Mg = 9:1 (10 nm) / CPL (40 nm).

[0125] The electroluminescent devices in the above examples and comparative examples were fabricated into samples of 30 mm × 30 mm, and then under the same device fabrication process conditions, the anode and cathode were connected by a commonly known driving circuit in the industry to characterize the OLED electroluminescent device, and the test results are shown in Table 2.

[0126] Table 2 Performance test results of electroluminescent devices

[0127] (Note: The current density during the test was 10 mA / cm, and LT95 refers to the time it takes for the device brightness to decay to 95% of the initial brightness.) It can be seen from the test data in Table 2 that, compared with Examples 4 to 33 and Comparative Examples 1 to 3, 1) The test devices prepared with the preferred benzocycloheptanone carbazole derivatives of the present invention as the material of the light-emitting layer 6 have obvious advantages in comprehensive luminous efficiency. 2) It can be seen from Examples 4 to 18 that for the test devices prepared with the preferred compounds of the present invention as the host light-emitting materials, compared with Comparative Examples 1 and 2, the driving voltage is significantly reduced, the current efficiency is increased by about 35%, and the service life LT95 is extended by about 35%. 3) It can be seen from Examples 19 to 33 that for the test devices prepared with the preferred compounds of the present invention as the guest light-emitting materials, compared with Comparative Example 3, the comprehensive luminous performance is significantly improved, and the service life LT95 is extended by about 70%.

[0128] The above content is only to illustrate the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any modifications made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A benzocycloheptanone carbazole derivative, characterized in that: The structure is shown in general formula I: in, As the main structure; L is selected from substituted or unsubstituted C6~C 40 aryl, or selected from substituted or unsubstituted C4~C 40 heteroaryl; The bonding mode of L to the main structure is single bond.

2. The benzocycloheptanonecarbazole derivative according to claim 1, characterized in that: Substituted or unsubstituted C4~C 40 In the heteroaryl group of , the heteroatom is O, S, N or Si.

3. The benzocycloheptanonecarbazole derivative according to claim 1, characterized in that: L is independently selected from the group L1-1 to L1-22, specifically: ； in, Indicates the position where L can bond to the main structure. Groups L1-9, L1-10, L1-12, L1-13, L1-14, L1-16, L1-17, L1-18 and L1-22 are connected by only one With the main structure Bonding.

4. The benzocycloheptanonecarbazole derivative according to claim 1, characterized in that: L is independently selected from the group L2-1 to L2-43, specifically: ； in, Indicates the position where L can bond to the main structure. Groups L2-4, L2-7, L2-8, L2-9, L2-10, L2-18, L2-19, L2-21, L2-24, L2-27, L2-28, L2-36, L2-38, L2-39, L2-40, L2-41, L2-42 and L2-43 are all connected by only one With the main structure Bonding.

5. The benzocycloheptanonecarbazole derivative according to claim 1, characterized in that: L is independently selected from the group L3-1 to L3-89, specifically: ； in, Indicates the position where L can bond to the main structure. Groups L3-4, L3-5, L3-19, L3-45, L3-52, L3-61, L3-78, L3-79, L3-87 and L3-88 are all connected by only one With the main structure Bonding.

6. The benzocycloheptanonecarbazole derivative according to any one of claims 1 to 5, characterized in that The benzocycloheptanone carbazole derivatives are selected from the following compounds: 。 7. The method for preparing the benzocycloheptanonecarbazole derivatives according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: Using 2-bromonitrobenzene and 2-aminophenylboronic acid pinacol ester as raw materials, a Suzuki coupling reaction is performed to obtain an intermediate M1-1; Step 2: Using intermediate M1-1 as a raw material, obtain intermediate M1-2 through Sandmeyer reaction; Step 3: Using intermediate M1-2 as a raw material, a [4+2] cycloaddition reaction is performed to obtain intermediate M1-3; Step 4: Using intermediate M1-3 as a raw material, a ring-closing reaction is performed to obtain intermediate M1; Step 5: Using intermediates M1 and LX as raw materials, an affinity substitution reaction is performed to obtain benzocycloheptanone carbazole derivatives; In LX, X is Cl or Br.

8. Use of the benzocycloheptanonecarbazole derivative according to any one of claims 1 to 6 in the preparation of an electroluminescent device.

9. An electroluminescent device, characterized in that: The invention comprises an anode layer (2), a cathode layer (10) and a light-emitting layer (6) located between the anode layer (2) and the cathode layer (10), wherein the material of the light-emitting layer (6) is selected from one or more of the benzocycloheptanonecarbazole derivatives according to any one of claims 1 to 6.

10. Use of the electroluminescent device according to claim 9 in the fields of luminous lighting, image display or optoelectronic signal transmission.

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