Benzocycloheptanoketocarbazole derivatives, processes for their preparation and use

Abstract

The application discloses a benzocycloheptanonecarbazole derivative, a preparation method and application thereof, and belongs to the field of organic light-emitting materials and semiconductor technologies. The benzocycloheptanonecarbazole is used as a main structure, the main structure belongs to a large rigid conjugated system, has high chemical stability, suitable singlet, triplet and molecular orbital energy level, and is an important unit for constructing an OLED light-emitting layer material; when the main structure and L1 substituents (L1-1 to L1-22), L2 substituents (L2-1 to L2-43) or L3 substituents (L3-1 to L3-89) match, a compound with obvious spatial stereoisomer can be formed. Experiments prove that the benzocycloheptanonecarbazole derivative is used as a light-emitting layer material in an OLED device, can effectively reduce a starting voltage, improve the light-emitting performance of the OLED device and prolong the service life of the OLED device.

Description

Technical Field

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

[0002] In recent years, organic light-emitting diodes (OLEDs) have become a hot research topic in the lighting and display fields due to their exceptional properties, including self-luminescence, high brightness, high contrast, see-through, wearable, foldable, low energy consumption, wide viewing angle, and low-temperature resistance. A typical OLED device structure comprises an anode layer, a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), an emissive layer (EML), a hole blocking layer (HBL), an electron transport layer (ETL), an electron injection layer (EIL), and a cathode layer. When a voltage is applied between the anode and cathode layers, holes are injected from the anode and move through the HTL toward the EML. Simultaneously, electrons are injected from the cathode and move through the ETL toward the EML. In the EML, electrons and holes recombine to form excitons, which transfer energy to the emissive material, causing it to emit light. The choice of light-emitting layer materials will have a significant impact on the current efficiency, driving voltage, luminous color purity, luminous brightness and lifespan of OLED devices. Therefore, exploring light-emitting layer materials with higher performance remains a key task in the current development of the OLED industry.

[0003] Chinese patent application publication number CN112174874A discloses an organic compound and an organic optoelectronic device using the compound. The patent provides a compound capable of serving as a functional layer material for an organic electroluminescent device. The compound has matching HOMO and triplet energy levels, and can limit the luminescent region of excitons in the organic electroluminescent device, thereby improving the efficiency of the device and reducing the voltage. However, the driving voltage of OLED devices prepared based on this compound is not ideal.

[0004] A kind of organic luminescent compound containing dibenzoheterocyclic heptane ketone, preparation method and application of Chinese patent application with disclosure No.CN116444502A provides a kind of organic luminescent compound containing dibenzoheterocyclic heptane ketone, the organic luminescent compound although has lower sublimation temperature and decomposition temperature, thin film morphology is stable, can be regulated by changing the chemical structure of connection Conjugated length and the color of luminescence of material, by changing the modification group on the aromatic structure, improve the physical properties of compound and the performance of optoelectronic device based on it.But, the OLED device prepared based on the organic luminescent compound of this kind is not ideal in service life.

[0005] Therefore, in order to meet the higher requirements of people for OLED device, it is urgent to develop higher performance light-emitting layer material. SUMMARY

[0006] In order to overcome the shortcomings of the prior art, the purpose of the present application is to provide benzocycloheptanone and carbazole derivatives and their preparation method and application, to solve the technical problems that the driving voltage and service life of existing luminescent materials cannot meet the demand.

[0007] In order to achieve the above purpose, the technical scheme of the present application is adopted to achieve the above purpose:

[0008] The first aspect of the present application discloses benzocycloheptanone and carbazole derivatives, the structure is shown as general formula I:

[0009]

[0010] Among them, It is the main structure;

[0011] L is selected from substituted or unsubstituted C6~C 40 Aryl, or selected from substituted or unsubstituted C4~C 40 Heteroaryl;

[0012] The bonding mode of L and the main structure is single bond bonding.

[0013] Preferably, in the substituted or unsubstituted C4~C 40 Heteroaryl, heteroatom is O, S, N or Si.

[0014] The second aspect of the present application discloses a preparation method of benzocycloheptanone and carbazole derivatives, comprising the following steps:

[0015] Step one, 2-bromonitrobenzene and 2-amino phenylboronic acid pinacol ester are used as raw materials, and intermediate M1-1 is obtained by suzuki coupling reaction;

[0016] Step two, intermediate M1-1 is used as raw material, and intermediate M1-2 is obtained by sandmeyer reaction;

[0017] Step three, taking intermediate M1-2 as raw material, through [4+2] cycloaddition reaction, intermediate M1-3 is obtained;

[0018] Step four, taking intermediate M1-3 as raw material, through ring closure reaction, intermediate M1 is obtained;

[0019] Step five, taking intermediate M1 and L-X as raw material, through affinity substitution reaction, benzocycloheptanone-perimidine derivative is obtained;

[0020] In L-X, X is Cl or Br.

[0021] The third aspect of the present application discloses the application of the above-mentioned benzocycloheptanone-perimidine derivative in the preparation of electroluminescent devices.

[0022] The fourth aspect of the present application discloses an electroluminescent device, which comprises an anode layer, a cathode layer and a light-emitting layer between the anode layer and the cathode layer, and the material of the light-emitting layer is selected from one or more of the above-mentioned benzocycloheptanone-perimidine derivatives.

[0023] The fifth aspect of the present application discloses the application of the above-mentioned electroluminescent device in the field of light-emitting illumination, image display or photoelectric signal transmission.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] The benzocycloheptanone-perimidine derivative provided by the present application takes benzocycloheptanone-perimidine as the main body structure, the main body structure belongs to a large rigid conjugated system, has high chemical stability, and has suitable singlet, triplet and molecular orbital energy levels, and is an important unit for constructing OLED light-emitting layer materials; when the main body structure and L1 substituent (L1-1~L1-22), L2 substituent (L2-1~L2-43) or L3 substituent (L3-1~L3-89) match, a compound with obvious spatial stereoisomerism can be formed (e.g., taking L as 5-substituted phenanthrene). Figure 1 Experiments prove that the benzocycloheptanone-perimidine derivative has strong electronegativity (C=O double bond) and rigidity, excellent light-emitting performance, and can be used as a light-emitting material to prepare the light-emitting layer of an OLED device, effectively reduce the starting voltage of the OLED device, improve the light-emitting performance of the OLED device, and prolong the service life of the OLED device.

[0026] Further, when L is selected from groups L1-1~L1-22, the benzocycloheptanone-perimidine 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.

[0027] Further, when L is selected from groups L2-1~L2-43, the benzocycloheptanonecarbazole derivative has a large conjugated π electron system, which is beneficial to hole transport and light emission, and the benzocycloheptanonecarbazole derivative further contains an electron-donating group, which can improve the hole injection and transport capacity, and can be used to prepare a light-emitting layer of an OLED device as a hole transport type host light-emitting material.

[0028] Further, when L is selected from groups L3-1~L3-89, the benzocycloheptanonecarbazole derivative contains an electron-donating group and an electron-withdrawing group, forms a D (Donor)-A (Acceptor) type molecule, has a thermally activated delayed fluorescence (TADF; Thermally Activated Delayed Fluorescence) property, and can be used to prepare a light-emitting layer of an OLED device as a guest light-emitting material. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 A spatial stereoscopic isomerogram of a benzocycloheptanonecarbazole derivative (L is a 5-substituted phenanthrene) and a host structure of the present application;

[0030] Figure 2 A sectional view of an organic electroluminescent device of the present application;

[0031] Figure 3 A nuclear magnetic spectrum of a compound H1-14 of the present application;

[0032] Figure 4 A nuclear magnetic spectrum of a compound H2-22 of the present application;

[0033] Figure 5 A nuclear magnetic spectrum of a compound H3-23 of the present application.

[0034] BRIEF DESCRIPTION OF DRAWINGS

[0035] 1 - substrate layer, 2 - anode layer, 3 - hole injection layer, 4 - hole transport layer, 5 - electron blocking layer, 6 - light-emitting layer, 7 - hole blocking layer, 8 - electron transport layer, 9 - electron injection layer, 10 - cathode layer, 11 - cover layer. DETAILED DESCRIPTION

[0036] To help those skilled in the art understand the features and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meanings understood by those skilled in the art regarding the present invention. In the event of any conflict, the definitions in this specification shall prevail. The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not in any way limit the scope of the present invention. That is, the present invention can be implemented without being limited by any particular theory or mechanism.

[0037] All features, such as values, amounts, amounts, and concentrations, described herein as numerical ranges or percentage ranges are provided for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to include and specifically disclose all possible subranges and individual values ​​within the range (including integers and fractions).

[0038] In this article, unless otherwise specified, "D" in the structural formula represents "deuterium".

[0039] The present invention provides benzocycloheptanone-carbazole derivatives, the structure of which is shown in the general formula I:

[0040]

[0041] in, As the main structure;

[0042] L is selected from substituted or unsubstituted C6~C 40 aryl, substituted or unsubstituted C4~C 40 The heteroaryl group, wherein the heteroatom in the heteroaryl group is, but not limited to, O, S, N or Si;

[0043] The bonding mode between L and the main structure is single bond;

[0044] 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:

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057] ;

[0058] In the above groups, " indicates the position where L can be bonded 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 all connected by only one " " and the main structure Bonding; 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 " " and the main structure Bonding; 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 " " and the main structure bonding.

[0059] The present invention also provides a method for preparing the above-mentioned benzocycloheptanonecarbazole derivative, comprising the following steps:

[0060]

[0061] Step 1: Using 2-bromonitrobenzene and 2-aminophenylboronic acid pinacol ester as raw materials, a Suzuki coupling reaction is performed to obtain the intermediate M1-1;

[0062] Step 2: Using intermediate M1-1 as a raw material, intermediate M1-2 is obtained by Sandmeyer reaction;

[0063] Step 3: Using intermediate M1-2 as a raw material, a [4+2] cycloaddition reaction is performed to obtain intermediate M1-3;

[0064] Step four, taking intermediate M1-3 as raw material, a ring closing reaction is carried out to obtain intermediate M1;

[0065] Step five, taking intermediate M1 and L-X (i.e. compound l) as raw material, an affinity substitution reaction is carried out to obtain benzocycloheptanone and carbazole derivative;

[0066] In L-X, L is independently selected from groups L1-1~L1-22, L2-1~L2-43, L3-1~L3-89 and corresponding derivatives, and X is Cl or Br.

[0067] Based on the above preparation method, the following compounds are synthesized according to the present application:

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094] .

[0095] The present application also provides an electroluminescent device, as shown, comprising 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 in the direction from anode to cathode; 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 form a functional organic layer. Figure 2 As the substrate layer 1, it is required to have high mechanical strength, excellent thermal stability, excellent waterproofness and excellent transparency;

[0096] As the anode layer 2, in order to enable the hole 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. As specific examples of the material of the anode layer 2 that can be used, there are 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;

[0097] 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 form a functional organic layer, which can be formed between the electrodes (the anode layer 2 and the cathode layer 10) by various means or methods such as vacuum thermal evaporation, spin coating and printing. The hole injection layer 3, the hole transport layer 4, the electron blocking layer 5, the hole blocking layer 7, the electron transport layer 8 and the electron injection layer 9 are prepared by selecting corresponding functional layer materials with excellent cost performance in the industry, and 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 layer except for the light emitting layer 6 can be selected from organic small molecules, organic macromolecules and polymers, and combinations thereof.

[0098] ​

[0099] MoO3 is preferable as the material of the hole injection layer 3;

[0100] As the material of the hole transport layer 4, one of the following materials can be selected:

[0101]

[0102] As the material of the electron blocking layer 5, one of the following materials can be selected:

[0103]

[0104] As the light emitting layer 6, a host light emitting material and a guest light emitting material are co-evaporated in a mass ratio of 98:2. The host light emitting material is selected from any one of the compounds H1-1~H1-28 and H2-1~H2-56 of the present application, and the guest light emitting material is preferably selected from any one of the compounds H3-1~H3-99 of the present application. Alternatively, the host light emitting material is preferably selected from any one of the compounds H1-1~H1-28 of the present application, and the guest light emitting material is selected from any one of the compounds H2-1~H2-56 of the present application.

[0105] As the material of the hole blocking layer 7, one of the following materials is selected:

[0106] As the material of the electron transport layer 8, one of the following materials is selected:

[0107]

[0108] As the cathode layer 10, a material having a small work function is preferable in order to easily inject electrons into the functional organic layer. Specific examples of the material of the cathode layer 10 include metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or alloys thereof, and multi-layered structure materials such as LiF-Al, LiO2-Al, Mg-Al, or Mg-Ag.

[0109] As the cover layer 11, the refractive index of the surface of the cathode layer 10 can be improved, and the light extraction efficiency can be improved. As the material of the cover layer 11, the following material is preferable:

[0110] The present application also provides a method for manufacturing the electroluminescent device. After pretreatment and cleaning, the substrate layer 1 is adhered with the anode layer 2, and then 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 are sequentially evaporated to a predetermined thickness. Then, the cathode layer 10 and the cover layer 11 are sputtered in a low temperature environment, and finally, the device is packaged by a conventional device testing packaging method to obtain the electroluminescent device. ​​​​​​

[0111] The electroluminescent device provided by the present application can be applied to the field of luminescent illumination, image display or photoelectric signal transmission.

[0112] The present application is further described below in conjunction with specific examples. Those skilled in the art can refer to the preparation method of the compound of general formula I, the preparation method of intermediate M1 of example 1 and the specific examples described below to prepare compounds H1-1~H1-28, H2-1~H2-56 and H3-1~H3-99. It should be understood that these examples are only used to illustrate the present application and are not used to limit the scope of the present application. In addition, it should be understood that those skilled in the art can make various modifications or changes to the present application after reading the description of the present application, and these equivalent forms also fall within the scope defined by the claims attached hereto.

[0113] The following examples use conventional apparatus in the art. The experimental method in the following examples is not specified, which is usually carried out according to the conventional conditions, or according to the conditions recommended by the manufacturer. Various raw materials are used in the following examples, unless otherwise specified, and the conventional commercially available products are used, which are of the conventional specifications in the art.

[0114] Example 1 Synthesis of compound H1-14

[0115] 1. Synthesis of intermediate M1:

[0116]

[0117] Step one: under nitrogen protection, 1.0 mol of 2-bromonitrobenzene, 1.0 mol of 2-aminobenzenesulfonic acid pinacol ester, 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 were added into a 3 L reaction flask and mixed, then the reaction system was heated to 90℃, and reacted for 12 h. After the reaction was completed, the reaction liquid was cooled to room temperature, extracted with ethyl acetate and water. The organic phase was dried with anhydrous magnesium sulfate, concentrated, recrystallized, and the obtained crude product was purified by silica gel column chromatography to obtain intermediate M1-1 (178 g, yield 83%), which showed a molecular weight of 215.1 by liquid chromatography-mass spectrometry (LC-MS).

[0118] Step two: In a 3 L reaction flask, add 0.8 mol of intermediate M1-1, 800 mL of water and 200 mL of concentrated hydrochloric acid, then heat the mixture solution to 60°C until the mixture solution is clear. Then cool to 5°C, then add 150 mL of sodium nitrite (0.88 mol) aqueous solution for diazotization, stir for 30 min, then quickly add 150 mL of 3.2 mol / L potassium iodide aqueous solution, then slowly heat to boiling point, continue to reflux for 6 h. After the reaction is completed, cool the mixture to room temperature, quench the mixture with saturated sodium sulfate solution, adjust the pH to 9 with saturated sodium hydroxide aqueous solution. Extract the mixture with ethyl acetate several times, combine the organic phases, dry the organic phase with anhydrous magnesium sulfate, concentrate under reduced pressure, and purify the obtained crude product by silica gel column chromatography (ethyl acetate / petroleum ether) to obtain intermediate M1-2 (203 g, yield 78%), LC-MS shows the molecular weight is 325.0.

[0119] Step three: 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 (diphenylglycine) palladium, 1.8 mol of potassium phosphate and 1.5 L of N,N-dimethylformamide (N,N-dimethylformamide; DMF) in a 3 L reaction flask, start stirring, heat the reaction solution to 120°C for 12 h until the reaction is complete, then cool the reaction solution to room temperature, concentrate most of the solvent under reduced pressure, add water and ethyl acetate for extraction, dry the organic phase with anhydrous magnesium sulfate, concentrate, and purify the obtained crude product by silica gel column chromatography (ethyl acetate / petroleum ether) to obtain intermediate M1-3 (157 g, yield 78%), LC-MS shows the molecular weight is 302.1.

[0120] Step four: Under nitrogen protection, add 0.5 mol of intermediate M1-3, 1.0 mol of triphenylphosphine and 1.2 L of 1,2-dichlorobenzene in a 5 L three-necked flask, stir at 140°C for 3 h until the reaction is complete. After the reaction is completed, remove 1,2-dichlorobenzene under reduced pressure, add appropriate amount of water and dichloromethane for extraction, dry the organic phase with anhydrous MgSO4, filter, concentrate, and purify the obtained crude product by silica gel column chromatography (ethyl acetate / petroleum ether) to obtain intermediate M1, 89 g, yield 66%, HPLC content 98%, LC-MS shows the molecular weight is 270.1.

[0121] 2, synthesis of compound H1-14:

[0122]

[0123] Under 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 into a 100 mL three-necked flask, 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 which the reaction solution was warmed to 120°C and the reaction was continued for 10 h. After the reaction was completed, the reaction solution was filtered hot using diatomite, the filtrate was cooled to room temperature, purified water was added for washing, the organic phase was retained after separation, the aqueous phase was extracted with ethyl acetate, the organic phases were combined, dried over anhydrous magnesium sulfate, concentrated, and columned (ethyl acetate / petroleum ether) to obtain compound H1-14, 3.5 g in yield, 76%, the High Performance Liquid Chromatography (HPLC) content was 99%, LC-MS showed that the molecular weight was 462.3, and the nuclear magnetic hydrogen spectrum was as shown in Figure 3 .

[0124] Nuclear magnetic hydrogen spectrum data of compound H1-14: 1 H NMR (500 MHz, CD3OH )δ 8.58 (dd, J = 14.8,3.2 Hz, 1H), 8.34 (dd, J = 14.7, 3.3 Hz, 1H), 7.94 – 7.56 (m, 7H), 7.54 – 7.08(m, 8H), 1.69 (s, 6H).

[0125] According to the synthesis method of Reference Example 1, the raw material reacted with intermediate M1 was replaced by:

[0126]

[0127]

[0128]

[0129]

[0130] , to synthesize compounds H1-1~H1-13, H1-15~H1-28.

[0131] Example 2 Synthesis of compound H2-22

[0132]

[0133] The synthesis procedure of reference compound H1-14 was followed, charging 0.01 mol of M1 and 0.0105 mol of 2-bromo-9,9'-spirobifluorene (l 2-30 ), to obtain compound H2-22, 4.4 g in yield, 73%, HPLC content 99%, LC-MS showed the molecular weight of 600.3, the nuclear magnetic hydrogen spectrum as Figure 4 shown.

[0134] The nuclear magnetic hydrogen spectrum data of compound H2-22: 1 H NMR (500 MHz, CD3OH )δ 8.58 (dd, J = 7.5,1.5 Hz, 1H), 8.34 (dd, J = 7.4, 1.5 Hz, 1H), 7.87 (ddd, J = 16.6, 7.5, 1.5 Hz,3H), 7.73 (ddd, J = 11.2, 7.3, 1.5 Hz, 4H), 7.62 (ddd, J = 13.7, 7.5, 1.5 Hz,2H), 7.50 (dd, J = 7.0, 2.0 Hz, 1H), 7.42 – 7.08 (m, 12H), 7.00 (td, J = 7.4, 1.5Hz, 1H)。

[0135] The synthesis procedure of reference compound H1-14 was followed, charging 0.01 mol of M1 and 0.0105 mol of 2-bromo-9,9'-spirobifluorene (l

[0136]

[0137]

[0138]

[0139]

[0140]

[0141]

[0142]

[0143]

[0144] ​, to synthesize compounds H2-1~H2-21, H2-23~H2-56.

[0145] Example 3 Synthesis of compound H3-23

[0146]

[0147] According 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 used as raw materials to synthesize compound H3-23, 4.3 g in weight, 72% in yield, 99% in HPLC content, and LC-MS showed that the molecular weight was 601.2, and the hydrogen spectrum was as shown in Figure 5 .

[0148] The hydrogen spectrum data of compound H3-23: 1 H NMR (500 MHz, CD3OH ) δ 9.09 (t, J = 3.0Hz, 2H), 8.54 (ddd, J = 23.1, 14.8, 3.1 Hz, 3H), 8.34 (dd, J = 14.7, 3.3 Hz, 1H),8.23 – 7.95 (m, 6H), 7.85 (td, 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).

[0149] According to the synthesis method of Example 3, the raw material reacted with intermediate M1 was replaced by:

[0150]

[0151]

[0152]

[0153]

[0154]

[0155]

[0156]

[0157]

[0158] , synthetic compounds H3-1~H3-22, H3-24~ H3-99.

[0159] The electroluminescent devices of Examples 4~33 and Comparative Examples 1~3 were prepared according to the structural information of the light-emitting layer 6 of the electroluminescent device given in Table 1.

[0160] Table 1 Structure of the light-emitting layer of the electroluminescent device

[0161]

[0162] (Note: "Host:Dopant" refers to the mass ratio of the host light-emitting material and the guest light-emitting material.)

[0163] Example 4 Electroluminescent device containing compound H1-1

[0164] An electroluminescent device containing compound H1-1, comprising, in order from the anode to the cathode, a polyethylene terephthalate (PET) plastic, an indium tin oxide (ITO) conductive glass, MoO3, HT-2, EB-2, a light-emitting layer 6, HB-1, ET-2, LiF, Al-Mg (Al:Mg=9:1), and CPL; wherein the light-emitting layer 6 comprises H1-1 and Ir(piq)3 in a mass ratio of 98:2.

[0165] The above method for preparing the electroluminescent device containing compound H1-1, comprising the following steps:

[0166] Step 1, using 1.5 mm of PET plastic as the substrate layer 1, and 0.15 mm of ITO conductive glass as the anode layer 2, washing in the order of alkali washing, pure water washing, drying, and ultraviolet-ozone washing to remove organic residues on the surface of the PET plastic and the ITO conductive glass.

[0167] Step 2, a layer of ITO conductive glass is adhered on the PET plastic, a vacuum evaporation device is used to evaporate MoO3 with a film thickness of 20 nm as a hole injection layer 3, then evaporate HT-2 with a thickness of 110 nm as a hole transport layer 4, then evaporate EB-2 with a thickness of 30 nm as an electron blocking layer 5, then continue to evaporate the light-emitting layer 6 of the compound H1-1 and Ir(piq)3 with a mass ratio of 98:2 with a thickness of 60 nm, then continue to evaporate HB-1 with a thickness of 10 nm as a hole blocking layer 7 on the light-emitting layer 6, then continue to evaporate ET-2 with a thickness of 30 nm as an electron transport layer 8, then continue to evaporate LiF with a thickness of 16 nm as an electron injection layer 9 on the electron transport layer 8, after the electron injection layer 9 is evaporated, a low-temperature sputtering method is used to sputter Al-Mg (Al:Mg=9:1) alloy with a thickness of 10 nm as a cathode layer 10, and finally continue to evaporate CPL with a thickness of 40 nm as a cover layer 11 on the cathode layer 10.

[0168] Step 3, vacuum packaging is performed on the MoO3, HT-2, EB-2, light-emitting layer 6, HB-1, ET-2 and LiF layers to obtain an electroluminescent device.

[0169] Examples 5 to 18

[0170] The difference from Example 4 is that in the light-emitting layer 6, the 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 host light-emitting material of the light-emitting layer 6.

[0171] Examples 19 to 33

[0172] The difference from Example 4 is that in the light-emitting layer 6, BH-1 is selected as the host light-emitting material of the light-emitting layer 6, and the 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 material of the light-emitting layer 6.

[0173] Comparative Example 1

[0174] The difference from Example 4 is that in the light-emitting layer 6, BH-1 is used as the host light-emitting material.

[0175] 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).

[0176] Comparative Example 2

[0177] The difference from Example 4 is that BH-1 is used as the host light-emitting material in the light-emitting layer 6, and the compound in the Chinese patent application with the publication number CN116444502A is used as the guest light-emitting material. as the host light-emitting material.

[0178] 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).

[0179] Comparative Example 3

[0180] The difference from Example 4 is that BH-1 is used as the host light-emitting material in the light-emitting layer 6, and the compound in the Chinese patent application with the publication number CN116444502A is used as the guest light-emitting material. as the host light-emitting material.

[0181] 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).

[0182] The electroluminescent devices in the above examples and comparative examples are prepared into samples of 30 mm x 30 mm, and then the anode and cathode are connected by using an industry-known driving circuit under the same device manufacturing process conditions, and the OLED electroluminescent device is characterized, and the test results are shown in Table 2.

[0183] Table 2 Performance test results of electroluminescent devices

[0184]

[0185] (Note: the current density during the test is 10 mA / cm, and LT95 refers to the time taken for the luminance of the device to decay to 95% of the initial luminance.)

[0186] As can be seen from the test data in Table 2, compared with Comparative Examples 1-3, the test devices prepared using the preferred benzocycloheptanonecarbazole derivatives of the present application as the material of the light-emitting layer 6 have the following advantages: 1) the test devices have obvious advantages in the overall light-emitting performance; 2) as can be seen from Examples 4-18, the test devices prepared using the preferred compounds of the present application as the host light-emitting material have a significantly reduced driving voltage, an about 35% increase in current efficiency, and an about 35% increase in the service life LT95, compared with Comparative Examples 1 and 2; and 3) as can be seen from Examples 19-33, the test devices prepared using the preferred compounds of the present application as the guest light-emitting material have significantly improved overall light-emitting performance and an about 70% increase in the service life LT95, compared with Comparative Example 3.

[0187] The above merely illustrates the technical idea of the present application and cannot be used to limit the protection scope of the present application. Any modification made according to the technical idea of the present application on the basis of the technical solutions falls within the protection scope of the claims of the present application.

Claims

1. A benzo-cycloheptanoknoncarbazole derivative characterized in that, The structure is shown in general formula I: wherein is the main structure; L is independently selected from groups L1-1~L1-22, L2-1~L2-43 and L3-1~L3-89, specifically: ； ； wherein denotes the position at which L can be bound to the host structure, the radicals L1-9, L1-10, L1-12, L1-13, L1-14, L1-16, L1-17, L1-18, L1-22, 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, L2-43, L3-4, L3-5, L3-19, L3-45, L3-52, L3-61, L3-78, L3-79, L3-87 and L3-88 are each bound to the host structure only via one bond.​ 2. The benzocycloheptanoketocarbazole derivative according to claim 1, characterized by The benzocycloheptanonecarbazole derivative is selected from the following compounds: 。 3. Process for the preparation of benzocycloheptanoketocarbazole derivatives according to claim 1 or 2, characterized in that, The method comprises the following steps: Step one, using 2-bromonitrobenzene and 2-aminobenzoic acid pinacol ester as raw materials, an intermediate M1-1 is obtained by Suzuki coupling reaction; Step two, using the intermediate M1-1 as raw material, an intermediate M1-2 is obtained by Sandmeyer reaction; Step three, using the intermediate M1-2 as raw material, an intermediate M1-3 is obtained by [4+2] cycloaddition reaction; Step four, using the intermediate M1-3 as raw material, an intermediate M1 is obtained by ring closure reaction; Step five, using the intermediate M1 and L-X as raw materials, a benzocycloheptanonecarbazole derivative is obtained by affinity substitution reaction; In L-X, L is independently selected from groups L1-1~L1-22, L2-1~L2-43 and L3-1~L3-89, and X is Cl or Br.

4. Use of the benzocycloheptanonecarbazole derivative of claim 1 or 2 in the preparation of an electroluminescent device.

5. An electroluminescent device, characterized by The electroluminescent device comprises an anode layer (2), a cathode layer (10) and a light-emitting layer (6) between the anode layer (2) and the cathode layer (10), and the material of the light-emitting layer (6) is selected from one or more of the benzocycloheptanonecarbazole derivatives of claim 1 or 2.

6. Use of the electroluminescent device of claim 5 in the field of light-emitting illumination, image display or photoelectric signal transmission.

Images