A pyrene derivative modified by carbazole and its preparation method and application

Abstract

The present invention provides a pyrene derivative modified by carbazole, a preparation method and an application thereof, and relates to the technical field of fluorescent dyes. The molecule of the pyrene derivative modified by carbazole with a structure shown in Formula I provided by the present invention contains a deep blue light chromophore pyrene group, which has a rigid plane and can reduce the non-radiative transition caused by the vibration of the molecular skeleton while ensuring that the material emits blue light, thereby improving the luminescence quantum yield of an organic electroluminescent device with the pyrene derivative modified by carbazole as the luminescence center. Moreover, the modified substituent (R) is a carbazole, dicarbazole and tricarbazole group with excellent carrier transport performance, which can improve the carrier transport performance of the dye molecule, thereby improving the luminescence performance of the electroluminescent device.

Description

Technical Field

[0001] The present invention relates to the technical field of fluorescent dyes, and in particular to a pyrene derivative modified with carbazole, and a preparation method and application thereof. Background Art

[0002] Organic Light-Emitting Diodes (OLEDs) are widely used in various fields due to their ultra-lightness, fast response, self-luminescence, full curing, good temperature characteristics, and flexible display.

[0003] In 1963, Pope et al. (J. Chem. Phys. 1963, 38: 2042-2043) studied a blue electroluminescent device based on anthracene single crystals (10-20 μm). However, due to the relatively thick luminescent layer of the anthracene single crystal and the limitations of the electrode materials (silver colloid and sodium chloride solution), the device had a high starting voltage of 400 V, and both efficiency and brightness were low. In 1987, CW Tang et al. (Appl. Phys. Lett. 1987, 51: 913-915) of Eastman Kodak Company in the United States used a double-layer structure with 8-hydroxyquinoline aluminum (Alq3) as the luminescent layer, aromatic diamine as the hole transport layer, ITO as the anode, and Mg:Ag (10:1) alloy as the cathode. They achieved high quantum efficiency (1%), luminous efficiency (1.5 lm / W), and brightness (>1000 cd / m 2 ) and devices with lower driving voltage (≤10V). This research progress has rekindled the hope of applying OLEDs to full-color flat-panel displays, and research on materials and devices has quickly become a research hotspot.

[0004] Luminescent dyes are considered core components of OLED devices. Based on their luminescence mechanisms, luminescent dyes are classified into fluorescent materials that emit in the singlet (S1) state and phosphorescent materials that emit in the triplet (T1) state. Spin statistics indicate that the internal quantum efficiency of OLEDs based on phosphorescent dyes can reach 100%, making phosphorescent dyes a research hotspot in the field of electroluminescent materials. Currently, among the three primary colors (red, green, and blue), the performance of red and green Ir(III) complex phosphorescent materials meets the requirements for OLED industrialization. However, the development of blue-emitting materials is far from ideal. The main reasons are: first, for blue-emitting dyes, manipulating the emission wavelength to blue-shift increases the nonradiative transition rate, thereby reducing the luminescence quantum efficiency; second, manipulating the emission wavelength of blue-emitting dyes often requires the introduction of highly electronegative fluorine atoms, which reduces the stability of such blue-emitting dyes. These issues have seriously hindered the application of OLEDs in full-color flat-panel displays and solid-state white light illumination. Therefore, the development of new blue fluorescent dyes with high fluorescence quantum efficiency and strong stability has become a major issue in this field. Summary of the Invention

[0005] In view of this, the object of the present invention is to provide a pyrene derivative modified by carbazole, a preparation method and an application thereof. The pyrene derivative modified by carbazole provided by the present invention has high luminescence quantum yield and strong stability as a blue light dye.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a carbazole-modified pyrene derivative having a structure shown in Formula I:

[0008]

[0009] In the formula I, R has any one of the following structures:

[0010]

[0011] The present invention provides a method for preparing a pyrene derivative based on carbazole modification according to the above technical solution, comprising the following steps:

[0012] Mixing 1,6-diisopropyl-3,8-dibromopyrene, a carbazole compound, an alkaline substance, a palladium catalyst, an organic ligand, and an anhydrous organic solvent, and performing a Buchwald-Hartwig reaction under a protective atmosphere to obtain the carbazole-modified pyrene derivative;

[0013] The carbazole compounds include 9H-carbazole, 3,6-di-tert-butyl-9H-carbazole, 9H-3,9'-biscarbazole or 9'H-9,3':6',9"-tricarbazole.

[0014] Preferably, the molar ratio of the 1,6-diisopropyl-3,8-dibromopyrene to the carbazole compound is 1:2 to 2.5.

[0015] Preferably, the alkaline substance comprises tert-butoxide and / or carbonate;

[0016] The molar ratio of the 1,6-diisopropyl-3,8-dibromopyrene to the alkaline substance is 1:4-10.

[0017] Preferably, the palladium catalyst comprises one or more of tetrakis(triphenylphosphine)palladium, palladium acetate and tris(dibenzylideneacetone)dipalladium;

[0018] The molar ratio of the 1,6-diisopropyl-3,8-dibromopyrene to the palladium catalyst is 1:0.005-0.02.

[0019] Preferably, the organic ligand includes one or more of 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl, 1,1'-binaphthyl-2,2'-bisdiphenylphosphine, 4,5-bisdiphenylphosphino-9,9-dimethylxanthene, tri(tert-butyl)phosphine and bisdiphenylphosphinoferrocene;

[0020] The molar ratio of the 1,6-diisopropyl-3,8-dibromopyrene to the organic ligand is 1:0.03-0.06.

[0021] Preferably, the anhydrous organic solvent includes one or more of a benzene solvent, an oxygen heterocyclic solvent and an ether solvent.

[0022] Preferably, the Buchwald-Hartwig reaction is carried out at a temperature of 80 to 120° C. and for a time of 5 to 15 hours.

[0023] The present invention provides the use of the carbazole-modified pyrene derivative described in the above technical solution or the carbazole-modified pyrene derivative prepared by the preparation method described in the above technical solution in an electroluminescent device.

[0024] The present invention also provides an electroluminescent device, comprising an anode, a hole injection layer, a hole transport layer, an exciton blocking layer, a light-emitting layer, an electron transport layer, an electron injection layer and a cathode stacked in sequence; the material of the light-emitting layer is the carbazole-modified pyrene derivative described in the above technical solution or the carbazole-modified pyrene derivative prepared by the preparation method described in the above technical solution.

[0025] The molecule of the carbazole-modified pyrene derivative with the structure shown in Formula I provided by the present invention contains a deep blue light chromophore pyrene group, which has a rigid plane and can reduce the non-radiative transition caused by the vibration of the molecular skeleton while ensuring that the material emits blue light, thereby improving the luminous quantum yield of the organic electroluminescent device with the carbazole-modified pyrene derivative as the luminescent center. Moreover, the modified substituent (R) is a carbazole, dicarbazole or tricarbazole group with excellent carrier transport performance, which can improve the carrier transport performance of the dye molecule, thereby improving the luminous performance and stability of the electroluminescent device. As shown in the test results of the embodiment, the maximum luminous brightness of the electroluminescent device provided by the present invention with the carbazole-modified pyrene derivative as the luminescent material is 5168~10673cd / m 2 The current efficiency is 1.15-2.64 cd / A, and the external quantum efficiency is 0.83-1.91%, indicating that the pyrene derivatives based on carbazole modification provided by the present invention have high luminescence quantum yield and strong stability as blue light dyes.

[0026] The preparation method of the carbazole-modified pyrene derivative provided by the present invention can be prepared through a one-step reaction, has a short route, high yield, simple operation, low cost, is green and environmentally friendly, and is suitable for industrial production. DETAILED DESCRIPTION

[0027] The present invention provides a carbazole-modified pyrene derivative having a structure shown in Formula I:

[0028]

[0029] In the formula I, R has any one of the following structures:

[0030]

[0031] In the present invention, the carbazole-modified pyrene derivative has a structure shown in the formula PyCz-1 (9,9'-(3,8-diisopropylpyrene-1,6-diyl)bis(9H-carbazole)), PyCz-2 (9,9'-(3,8-diisopropylpyrene-1,6-diyl)bis(3,6-di-tert-butyl-9H-carbazole)), PyCz-3 (9,9"-(3,8-diisopropylpyrene-1,6-diyl)bis(9H-3,9'-biscarbazole)), or PyCz-4 (9',9""-(3,8-diisopropylpyrene-1,6-diyl)bis(9'H-9,3':6',9"-tricarbazole)):

[0032]

[0033] The present invention provides a method for preparing a pyrene derivative based on carbazole modification according to the above technical solution, comprising the following steps:

[0034] Mixing 1,6-diisopropyl-3,8-dibromopyrene, a carbazole compound, an alkaline substance, a palladium catalyst, an organic ligand, and an anhydrous organic solvent, and performing a Buchwald-Hartwig reaction under a protective atmosphere to obtain the carbazole-modified pyrene derivative;

[0035] The carbazole compounds include 9H-carbazole, 3,6-di-tert-butyl-9H-carbazole, 9H-3,9'-biscarbazole or 9'H-9,3':6',9"-tricarbazole.

[0036] Unless otherwise specified, the raw materials used in the present invention are all commercially available products.

[0037] In the present invention, the molar ratio of the 1,6-diisopropyl-3,8-dibromopyrene to the carbazole compound is preferably 1:2-2.5, more preferably 1:2.1-2.4, and even more preferably 1:2.2-2.3.

[0038] In the present invention, the alkaline substance preferably includes tert-butoxide and / or carbonate; the tert-butoxide preferably includes sodium tert-butoxide and / or potassium tert-butoxide; the carbonate preferably includes one or more of sodium carbonate, potassium carbonate, and cesium carbonate. In the present invention, the molar ratio of 1,6-diisopropyl-3,8-dibromopyrene to the alkaline substance is preferably 1:4-10, more preferably 1:5-9, and even more preferably 1:6-8.

[0039] In the present invention, the palladium catalyst preferably includes one or more of tetrakis(triphenylphosphine)palladium, palladium acetate and tris(dibenzylideneacetone)dipalladium; the molar ratio of the 1,6-diisopropyl-3,8-dibromopyrene to the palladium catalyst is preferably 1:0.005-0.02, more preferably 1:0.01-0.015.

[0040] In the present invention, the organic ligand preferably includes one or more of 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl, 1,1'-binaphthyl-2,2'-bisdiphenylphosphine, 4,5-bisdiphenylphosphino-9,9-dimethylxanthene, tri(tert-butyl)phosphine, and bisdiphenylphosphinoferrocene. The molar ratio of 1,6-diisopropyl-3,8-dibromopyrene to the organic ligand is preferably 1:0.03-0.06, more preferably 1:0.04-0.05. In the present invention, the organic ligand functions to coordinate with the palladium catalyst, promote the Buchwald-Hartwig reaction, and improve the reaction efficiency.

[0041] In the present invention, the anhydrous organic solvent preferably includes one or more of a benzene solvent, an oxygen heterocycle solvent, and an ether solvent; the benzene solvent preferably includes toluene and / or xylene; the oxygen heterocycle solvent preferably includes 1,4-dioxane and / or tetrahydrofuran; and the ether solvent includes ethylene glycol dimethyl ether. In the present invention, the molar ratio of the amount of 1,6-diisopropyl-3,8-dibromopyrene to the anhydrous organic solvent is preferably 1 mmol:4-10 mL, more preferably 1 mmol:5-9 mL, and even more preferably 1 mmol:6-8 mL.

[0042] In the present invention, the temperature of the Buchwald-Hartwig reaction is preferably 80-120°C, more preferably 90-110°C, and even more preferably 100°C; the Buchwald-Hartwig reaction time is preferably 5-15 hours, more preferably 8-12 hours, and even more preferably 10 hours. The present invention does not particularly limit the protective atmosphere; any protective atmosphere familiar to those skilled in the art can be used, such as nitrogen, argon, or helium.

[0043] After the Buchwald-Hartwig reaction, the present invention preferably further includes post-treatment. The post-treatment preferably includes: cooling the resulting Buchwald-Hartwig reaction solution to room temperature, adding water to mix, extracting with an organic solvent, drying the resulting organic phase with a desiccant, performing solid-liquid separation, concentrating the resulting liquid fraction, and separating by column chromatography to obtain the carbazole-modified pyrene derivative. The present invention does not specifically limit the cooling method; any cooling method known to those skilled in the art can be employed, such as natural cooling. In the present invention, the organic solvent used for extraction preferably includes a halogenated alkane solvent or an ester solvent; the halogenated alkane solvent preferably includes dichloromethane and / or chloroform; and the ester solvent preferably includes ethyl acetate. In the present invention, the number of organic solvent extractions is preferably 1 to 5, more preferably 3. The ratio of the amount of 1,6-diisopropyl-3,8-dibromopyrene to the volume of the organic solvent used for a single organic solvent extraction is preferably 1 mmol:10 to 30 mL, more preferably 1 mmol:15 to 25 mL. In the present invention, the desiccant preferably includes anhydrous magnesium sulfate and / or anhydrous sodium sulfate. The present invention has no special limitation on the solid-liquid separation, and a solid-liquid separation method well known to those skilled in the art can be adopted, such as filtration. The present invention has no special limitation on the concentration, and a concentration method well known to those skilled in the art can be adopted, such as rotary evaporation. In the present invention, the eluent used in the column chromatography separation preferably includes a mixed solvent of a high-polarity solvent-low-polarity solvent, and the high-polarity solvent preferably includes one or more of dichloromethane, chloroform, toluene, benzene and ethyl acetate; the low-polarity solvent preferably includes one or more of petroleum ether and n-hexane; the volume ratio of the high-polarity solvent to the low-polarity solvent in the eluent is preferably 1:5 to 5:1, more preferably 1:3 to 3:1; in a specific embodiment of the present invention, the eluent is preferably a mixed solvent of dichloromethane-petroleum ether.

[0044] The present invention provides the use of the carbazole-modified pyrene derivative described in the above technical solution or the carbazole-modified pyrene derivative prepared by the preparation method described in the above technical solution in an electroluminescent device.

[0045] The present invention also provides an electroluminescent device, comprising an anode, a hole injection layer, a hole transport layer, an exciton blocking layer, a light-emitting layer, an electron transport layer, an electron injection layer and a cathode stacked in sequence; the material of the light-emitting layer is the carbazole-modified pyrene derivative described in the above technical solution or the carbazole-modified pyrene derivative prepared by the preparation method described in the above technical solution.

[0046] In the present invention, the material of the anode preferably includes ITO glass, zinc oxide, noble metal or transparent conductive polymer; the noble metal preferably includes Au; the transparent conductive polymer preferably includes polyaniline; the thickness of the anode is preferably 50 to 500 nm, more preferably 100 nm.

[0047] In the present invention, the material of the hole injection layer preferably includes one or more of hexaazatriphenylene-hexacarbonitrile (HAT-CN) and copper phthalocyanine (CuPc); the thickness of the hole injection layer is preferably 1 to 100 nm, more preferably 30 nm.

[0048] In the present invention, the material of the hole transport layer preferably includes one or more of N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB) and tetraphenylbenzene diamine compounds (N,N,N',N'-Tetraphenyl-1,1'-biphenyl-4,4'-diamine, abbreviated as TPD); the thickness of the hole transport layer is preferably 1 to 200 nm, more preferably 10 to 50 nm.

[0049] In the present invention, the material of the exciton blocking layer preferably includes 4,4',4"-tris(carbazol-9-yl)triphenylamine (TCTA); the thickness of the exciton blocking layer is preferably 1 to 100 nm, more preferably 10 to 50 nm.

[0050] In the present invention, the thickness of the light-emitting layer is preferably 1 to 100 nm, more preferably 20 to 50 nm.

[0051] In the present invention, the material of the electron transport layer preferably includes 1,10-phenanthroline (Bphen); the thickness of the electron transport layer is preferably 1 to 100 nm, more preferably 30 to 50 nm.

[0052] In the present invention, the material of the electron injection layer preferably includes Liq; the thickness of the electron injection layer is preferably 0.5 to 10 nm, more preferably 1 to 3 nm.

[0053] In the present invention, the material of the cathode preferably includes Al; the thickness of the cathode is preferably 50 to 250 nm, more preferably 100 to 150 nm.

[0054] In the present invention, the method for preparing the electroluminescent device preferably comprises the following steps:

[0055] The anode material is sequentially washed and subjected to UV-ozone treatment to obtain an anode;

[0056] A hole injection layer, a hole transport layer, an exciton blocking layer, a light-emitting layer, an electron transport layer, an electron injection layer and a cathode are sequentially deposited on the surface of the anode to obtain an electroluminescent device.

[0057] The present invention sequentially washes and then treats the anode material with ultraviolet-ozone to obtain the anode. In the present invention, the washing preferably includes sequentially washing with a glass detergent, ultrasonic water washing, and ultrasonic acetone washing. The present invention does not particularly limit the glass detergent; any glass detergent known to those skilled in the art can be used. The ultrasonic water washing and ultrasonic acetone washing are each performed 2 to 4 times, more preferably 3 times. In the present invention, the ultraviolet-ozone treatment preferably has a wavelength of 230 nm and is preferably performed for 1 to 60 minutes, more preferably 15 to 30 minutes.

[0058] After obtaining the anode, the present invention sequentially deposits a hole injection layer, a hole transport layer, an exciton blocking layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode on the surface of the anode by vapor deposition to obtain an electroluminescent device. In the present invention, the vacuum degree of the vapor deposition of the hole injection layer, the hole transport layer, the exciton blocking layer, the light-emitting layer, the electron transport layer, the electron injection layer, and the cathode is independently less than 3×10 -5 Pa; The present invention does not specifically limit the conditions for the evaporation deposition, and the conditions for evaporation deposition of the hole injection layer, hole transport layer, exciton blocking layer, light-emitting layer, electron transport layer, electron injection layer and cathode familiar to those skilled in the art can be adopted.

[0059] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0060] Example 1

[0061]

[0062] Under anhydrous and oxygen-free conditions, 2.5 mmol of 1,6-diisopropyl-3,8-dibromopyrene, 5.5 mmol of 9H-carbazole, 15 mmol of sodium tert-butoxide, 0.025 mmol of tetrakistriphenylphosphine palladium, and 0.12 mmol of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl were dissolved in 15 mL of anhydrous toluene. The mixture was reacted at 110°C under nitrogen protection for 12 h. The mixture was cooled to room temperature, mixed with 50 mL of water, and extracted with dichloromethane three times (50 mL of dichloromethane per time). The organic phases were combined, dried over anhydrous magnesium sulfate, filtered, and the filtrate was spin-dried. The crude product was purified by column chromatography to obtain PyCz-1(9,9'-(3,8-diisopropylpyrene-1,6-diyl)bis(9H-carbazole) in a yield of 65%. The ESI-MS (M+1) theoretical value of PyCz-1 is 616.79, and the measured value [M+1] + is 616.79; 1 H NMR(400MHz, CDCl3):8.07-8.09(m,4H),7.97-8.00(m,2H),7.74-7.76(m,2H),7.52-7.54(m,4H),7 .46-7.47(m,2H),7.34-7.38(m,4H),7.22-7.26(m,4H),3.26-3.31(m,2H),1.37(d,J=3.6Hz,12H).

[0063] Example 2

[0064]

[0065] PyCz-2 (9,9'-(3,8-diisopropylpyrene-1,6-diyl)bis(3,6-di-tert-butyl-9H-carbazole)) was prepared according to the method of Example 1, with the only difference from Example 1 being that 9H-carbazole was replaced with 3,6-di-tert-butyl-9H-carbazole, to give PyCz-2 in 62% yield. The ESI-MS (M+1) theoretical value of PyCz-2 was 841.22, and the measured value [M+1] was + is 841.23; 1 H NMR(400MHz, CDCl3):7.92-7.98(m,6H),7.86-7.89(m,2H),7.55-7.58(m,4H),7.47 (s,2H),7.27-7.30(m,4H),3.29-3.34(m,2H),1.40(s,36H),1.37(d,J=3.6Hz,12H).

[0066] Example 3

[0067]

[0068] The product was prepared according to the method of Example 1, except that 9H-carbazole was replaced with 9H-3,9'-biscarbazole to obtain PyCz-3 (9,9"-(3,8-diisopropylpyrene-1,6-diyl)bis(9H-3,9'-biscarbazole)) in 60% yield. The ESI-MS (M+1) theoretical value of PyCz-3 was 947.17, and the measured value [M+1] was + is 947.19; 1 H NMR(400MHz, CDCl3):8.00-8.06(m,6H),7.96-7.98(m,4H),7.86-7.89(m,2H),7.70-7.73( m,2H),7.44-7.48(m,10H),7.20-7.32(m,12H),3.29-3.34(m,2H),1.37(d,J=3.6Hz,12H).

[0069] Example 4

[0070]

[0071] The product was prepared according to the method of Example 1, except that 9H-carbazole was replaced with 9'H-9,3':6',9"-tricarbazole to obtain PyCz-4 (9',9"""-(3,8-diisopropylpyrene-1,6-diyl)bis(9'H-9,3':6',9"-tricarbazole) in 59% yield. The ESI-MS (M+1) theoretical value of PyCz-4 was 1277.55, and the measured value [M+1] was 1277.55. + is 1277.57; 1 HNMR (400MHz, CDCl3): 7.97-8.03 (m, 14H), 7.86-7.89 (m, 2H), 7.46-7.56 (m, 18H), 7.20-7.28 (m, 16H), 3.29-3.34 (m, 2H), 1.37 (d, J = 3.6Hz, 12H).

[0072] Example 5

[0073] Electroluminescent devices were prepared using dyes PyCz-1, PyCz-2, PyCz-3 and PyCz-4 as luminescent centers, respectively. The structures of the electroluminescent devices were: ITO / HAT-CN (30 nm) / NPB (10 nm) / TCTA (10 nm) / PyCz (20 nm) / Bphen (30 nm) / Liq (1 nm) / Al (100 nm), where PyCz was PyCz-1, PyCz-2, PyCz-3 or PyCz-4.

[0074] The preparation process of the electroluminescent device is as follows: 15Ω / sq ITO glass is used as the substrate, which is first cleaned with glass detergent, ultrasonically washed with deionized water three times, ultrasonically washed with acetone three times, and treated with UV-ozone for 15 minutes. A 30nm HAT-CN layer, a 10nm NPB layer, a 10nm TCTA layer, a 20nm PyCz (PyCz-1, PyCz-2, PyCz-3 or PyCz-4), a 30nm Bphen layer, a 1nm Liq layer, and a 100nm Al layer are sequentially deposited on the surface of the obtained ITO glass. During the evaporation deposition of each layer, the pressure of the vacuum chamber is <3×10 -5 Pa, four kinds of electroluminescent devices were obtained. The performance test results of the four kinds of electroluminescent devices are shown in Table 1.

[0075] Table 1 Performance of electroluminescent devices

[0076]

[0077]

[0078] As can be seen from Table 1, under the same device conditions, as the luminous brightness increases, the luminous efficiency of the electroluminescent device is significantly improved. The above excellent performance of the electroluminescent device indicates that the pyrene derivatives modified with carbazole prepared by the present invention have application value in the preparation of organic electroluminescent devices.

[0079] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A pyrene derivative modified with carbazole, characterized in that: It has the structure shown in Formula I: In the formula I, R has any one of the following structures:

2. The method for preparing the pyrene derivative based on carbazole modification according to claim 1, characterized in that: The following steps are involved: Mixing 1,6-diisopropyl-3,8-dibromopyrene, a carbazole compound, an alkaline substance, a palladium catalyst, an organic ligand and an anhydrous organic solvent, and performing a Buchwald-Hartwig reaction under a protective atmosphere to obtain the carbazole-modified pyrene derivative; The carbazole compounds include 3,6-di-tert-butyl-9H-carbazole, 9H-3,9'-biscarbazole or 9'H-9,3':6',9"-tricarbazole.

3. The preparation method according to claim 2, characterized in that: The molar ratio of the 1,6-diisopropyl-3,8-dibromopyrene to the carbazole compound is 1:2-2.

5.

4. The preparation method according to claim 2, characterized in that: The alkaline substance includes tert-butoxide and / or carbonate; The molar ratio of the 1,6-diisopropyl-3,8-dibromopyrene to the alkaline substance is 1:4-10.

5. The preparation method according to claim 2, characterized in that: The palladium catalyst comprises one or more of tetrakis(triphenylphosphine)palladium, palladium acetate and tris(dibenzylideneacetone)dipalladium; The molar ratio of the 1,6-diisopropyl-3,8-dibromopyrene to the palladium catalyst is 1:0.005-0.

02.

6. The preparation method according to claim 2, characterized in that: The organic ligand includes one or more of 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl, 1,1'-binaphthyl-2,2'-bisdiphenylphosphine, 4,5-bisdiphenylphosphino-9,9-dimethylxanthene, tri(tert-butyl)phosphine and bisdiphenylphosphinoferrocene; The molar ratio of the 1,6-diisopropyl-3,8-dibromopyrene to the organic ligand is 1:0.03-0.

06.

7. The preparation method according to claim 2, characterized in that: The anhydrous organic solvent includes one or more of a benzene solvent, an oxygen heterocyclic solvent and an ether solvent.

8. The preparation method according to any one of claims 2 to 7, characterized in that: The temperature of the Buchwald-Hartwig reaction is 80-120° C. and the time is 5-15 hours.

9. Use of the carbazole-modified pyrene derivative according to claim 1 or the carbazole-modified pyrene derivative prepared by the preparation method according to any one of claims 2 to 8 in an electroluminescent device.

10. An electroluminescent device, comprising an anode, a hole injection layer, a hole transport layer, an exciton blocking layer, a light-emitting layer, an electron transport layer, an electron injection layer and a cathode stacked in sequence; characterized in that: The material of the light-emitting layer is the carbazole-modified pyrene derivative according to claim 1 or the carbazole-modified pyrene derivative prepared by the preparation method according to any one of claims 2 to 8.

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