阅读说明：本技术 一种化合物、光提取材料和有机电致发光器件 (Compound, light extraction material and organic electroluminescent device ) 是由 陈跃 丰佩川 邢其锋 胡灵峰 刘子彦 于 2020-04-16 设计创作，主要内容包括：本申请提供了一种通式(I)的化合物,其可以用于有机电致发光器件,作为光提取材料。该化合物具有高折射率和低折射率差,在光提取层厚度相同的情况下,可以更好地均衡不同颜色光的有机电致发光器件的出光率,即可以提高总体出光率。本申请还提供了一种包含通式(I)化合物的有机电致发光器件和显示装置。(The application provides a compound of a general formula (I), which can be used in an organic electroluminescent device as a light extraction material. The compound has high refractive index and low refractive index difference, and can better balance the light-emitting rates of organic electroluminescent devices with different colors of light under the condition that the thicknesses of the light extraction layers are the same, namely the total light-emitting rate can be improved. The present application also provides an organic electroluminescent device and a display device comprising the compound of formula (I).)

1. A compound of the general formula (I):

wherein X and Y are each independently selected from O, S, CR₁R₂Or NR₃；

L₁、L₂And L₃Each independently selected from the group consisting of a bond, an aromatic ring containing 6 to 18 carbon atoms, or a heteroaromatic ring of 2 to 18 carbon atoms, wherein the hydrogen atoms on the aromatic and heteroaromatic rings may each independently be deuterium, halogen, C₁-C₆Is substituted with an alkyl, phenyl, biphenyl, terphenyl or naphthyl group of (a), each heteroatom of the heteroaromatic ring being independently selected from O, S and N;

R₁、R₂and R₃Each independently selected from a straight or branched chain alkyl group containing 1 to 12 carbon atoms, an aromatic ring group containing 6 to 14 carbon atoms, or a heteroaromatic ring group containing 2 to 14 carbon atoms;

ar is selected from an aromatic ring group with 6-26 carbon atoms or a heteroaromatic ring group with 2-24 carbon atoms;

wherein R is₁、R₂、R₃And the hydrogen atoms on the aromatic or heteroaromatic ring groups in Ar may each independently be deuterium, halogen, C₁-C₆Alkyl, phenyl, biphenyl, terphenyl, or naphthyl;

the heteroatoms of the heteroaryl ring group are each independently selected from O, S and N.

2. The compound according to claim 1, wherein,

L₁、L₂and L₃Each independently selected from a chemical bond, an aromatic ring containing 6 to 12 carbon atoms, or a heteroaromatic ring of 2 to 12 carbon atoms, wherein the hydrogen atoms on the aromatic and heteroaromatic rings each independently may be substituted with deuterium, halogen, phenyl, biphenyl, or naphthyl, and the heteroatoms of the heteroaromatic rings each independently selected from O, S and N;

R₁、R₂and R₃Each independently selected from a straight or branched chain alkyl group having 1 to 6 carbon atoms, an aromatic ring group having 6 to 12 carbon atoms, or a heteroaromatic ring group having 2 to 12 carbon atoms;

ar is selected from an aromatic ring group with 6-14 carbon atoms or a heteroaromatic ring group with 2-12 carbon atoms;

wherein R is₁、R₂、R₃And the hydrogen atoms on the aromatic ring group and the heteroaromatic ring group in Ar each independently may be substituted with deuterium, halogen, phenyl, biphenyl, or naphthyl.

3. The compound according to claim 1, wherein,

L₁、L₂and L₃Each independently selected from a chemical bond or a subunit of benzene, biphenyl, terphenyl;

R₁、R₂and R₃Each independently selected from methyl, ethyl, cyclopentyl, cyclohexyl, the following groups unsubstituted or substituted with deuterium, halogen, phenyl, biphenyl or naphthyl: phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, triphenylene, pyridyl, dibenzofuranyl, dibenzothiophenyl, 9-dimethylfluorenyl, carbazole groups;

ar is selected from dibenzofuran, N-phenyl-carbazole, dibenzothiophene, biphenyl, 9-dimethylfluorene, spirobifluorene, terphenyl, unsubstituted or substituted by deuterium, halogen, phenyl, biphenyl or naphthyl.

4. The compound according to claim 1, wherein the compound is selected from the following compounds:

5. a light extraction material comprising a compound according to any one of claims 1-4.

6. The light extraction material of claim 5, wherein the refractive index of the light extraction material is > 1.85.

7. The light extraction material according to claim 5, wherein the difference between the refractive index for red light and the refractive index for blue light of the light extraction material is <0.2, preferably < 0.15.

8. The light extraction material of claim 5, wherein the evaporation temperature of the light extraction material is 330-400 ℃.

9. An organic electroluminescent device comprising at least one of the light extraction materials of claims 5-8.

10. A display device comprising the organic electroluminescent element according to claim 9.

Technical Field

The invention relates to the field of organic light-emitting display, in particular to a light extraction material and an organic electroluminescent device containing the light extraction material.

Background

An organic electroluminescent device is a multi-layered organic thin film structure in which a light emitting layer is positioned between a cathode and an anode. Light emitted from the light-emitting layer after energization is transmitted from the transparent electrode side, and the light is lost due to a waveguide effect such as total reflection between the respective film layers. A light extraction layer with high refractive index is added on the transparent electrode, so that the light extraction efficiency can be greatly improved.

The light extraction layer can be an inorganic compound which is characterized by high refractive index and is beneficial to light extraction, but the coating temperature is high (>1000 ℃), the coating damages an organic element, and the organic thin film evaporation temperature is low, and the organic thin film evaporation temperature is more advantageous than the inorganic compound in process.

The material mainly used for the O L ED light extraction layer is aromatic amine compound (CN103828485A) of Japan Tuotu valley at present, the aromatic amine compound has higher refractive index, however, the refractive index is increased along with the shortening of the wavelength, namely, the refractive index of red light is low, the refractive index of green light is higher, the refractive index of blue light is higher, the refractive index difference of blue light and red light is about 0.30. the difference of the refractive indexes causes serious trouble to the manufacture of a red, green and blue three-color device for O L ED display, because the light extraction layer has microcavity effect, has certain filtering effect on the wavelength of light emitted from a transparent electrode, if the thickness of the light extraction layer is proper, the effect of light extraction is enhanced, and the light extraction layer is improper, the light extraction rate is reduced.

L λ/(4n) equation (1)

More generally, the light extraction layer of the blue light has a small wavelength, the light extraction layer of the blue light device needs a small thickness, the light extraction layer of the green light device is thick, the wavelength of the red light is longest, and the light extraction layer of the red light device is thickest.

Disclosure of Invention

In view of the above problems of the prior art, the present application aims to provide a light extraction material having a smaller difference in refractive index for red light, green light and blue light and a larger refractive index, so that the optimal light extraction efficiency of red, green and blue light can be considered.

A first aspect of the invention provides a compound of general formula (I):

wherein X and Y are each independently selected from O, S, CR₁R₂Or NR₃

L₁、L₂And L₃Each independently selected from the group consisting of a bond, an aromatic ring containing 6 to 18 carbon atoms, or a heteroaromatic ring of 2 to 18 carbon atoms, wherein the hydrogen atoms on the aromatic and heteroaromatic rings may each independently be deuterium, halogen, C₁-C₆Is substituted with an alkyl, phenyl, biphenyl, terphenyl or naphthyl group of (a), each heteroatom of the heteroaromatic ring being independently selected from O, S and N;

R₁、R₂and R₃Each independently selected from a straight or branched chain alkyl group containing 1 to 12 carbon atoms, an aromatic ring group containing 6 to 14 carbon atoms, or a heteroaromatic ring group containing 2 to 14 carbon atoms;

ar is selected from an aromatic ring group with 6-26 carbon atoms or a heteroaromatic ring group with 2-24 carbon atoms;

wherein R is₁、R₂、R₃And the hydrogen atoms on the aromatic or heteroaromatic ring groups in Ar may each independently be deuterium, halogen, C₁-C₆Alkyl, phenyl, biphenyl, terphenyl, or naphthyl;

the heteroatoms of the heteroaryl ring group are each independently selected from O, S and N.

A second aspect of the present application provides a light extraction material comprising a compound provided herein.

A third aspect of the present application provides an organic electroluminescent device comprising at least one of the light extraction materials provided herein.

A fourth aspect of the present application provides a display apparatus comprising the organic electroluminescent device provided by the present application.

The compound provided by the application has a high refractive index and small difference between the refractive indexes of red light, green light and blue light. When the material is used as a light extraction material, the light extraction rate of the organic electroluminescent device can be improved, so that the light extraction rate of the red light, green light and blue light organic electroluminescent device can be improved in a balanced manner. The organic electroluminescent device comprises the compound as a light extraction material, has higher light extraction rate, and can improve the light extraction rate of red, green and blue organic electroluminescent devices in a balanced manner. The display device provided by the application has an excellent display effect.

Of course, not all advantages described above need to be achieved at the same time in the practice of any one product or method of the present application.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other embodiments can be obtained by using the drawings without creative efforts.

Fig. 1 is a schematic structural view of a typical organic electroluminescent device.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

A first aspect of the present application provides a compound of general formula (I):

wherein X and Y are each independently selected from O, S, CR₁R₂Or NR₃；

L₁、L₂And L₃Each independently selected from the group consisting of a bond, an aromatic ring containing 6 to 18 carbon atoms, or a heteroaromatic ring of 2 to 18 carbon atoms, wherein the hydrogen atoms on the aromatic and heteroaromatic rings may each independently be deuterium, halogen, C₁-C₆Is substituted with an alkyl, phenyl, biphenyl, terphenyl or naphthyl group of (a), each heteroatom of the heteroaromatic ring being independently selected from O, S and N;

R₁、R₂and R₃Each independently selected from a straight or branched chain alkyl group containing 1 to 12 carbon atoms, an aromatic ring group containing 6 to 14 carbon atoms, or a heteroaromatic ring group containing 2 to 14 carbon atoms;

ar is selected from an aromatic ring group with 6-26 carbon atoms or a heteroaromatic ring group with 2-24 carbon atoms;

wherein R is₁、R₂、R₃And the hydrogen atoms on the aromatic or heteroaromatic ring groups in Ar may each independently be deuterium, halogen, C₁-C₆Alkyl, phenyl, biphenyl, terphenyl, or naphthyl;

the heteroatoms of the heteroaryl ring group are each independently selected from O, S and N.

Preferably L₁、L₂And L₃Each independently selected from a chemical bond, an aromatic ring containing 6 to 12 carbon atoms, or a heteroaromatic ring of 2 to 12 carbon atoms, wherein the hydrogen atoms on the aromatic and heteroaromatic rings each independently may be substituted with deuterium, halogen, phenyl, biphenyl, or naphthyl, and the heteroatoms of the heteroaromatic rings each independently selected from O, S and N;

preferably, R₁、R₂And R₃Each independently selected from a straight or branched chain alkyl group having 1 to 6 carbon atoms, an aromatic ring group having 6 to 12 carbon atoms or a cyclic alkyl group having 2 to 12 carbon atomsA heteroaromatic ring group;

ar is selected from an aromatic ring group with 6-14 carbon atoms or a heteroaromatic ring group with 2-12 carbon atoms;

wherein R is₁、R₂、R₃And the hydrogen atoms on the aromatic and heteroaromatic ring groups in Ar each independently may be substituted with deuterium, halogen, phenyl, biphenyl, or naphthyl;

the heteroatom of the heteroaryl ring group is selected from O, S and N.

More preferably L₁、L₂And L₃Each independently selected from a chemical bond or a subunit of benzene, biphenyl, terphenyl;

R₁、R₂and R₃Each independently selected from methyl, ethyl, cyclopentyl, cyclohexyl, the following groups unsubstituted or substituted with deuterium, halogen, phenyl, biphenyl or naphthyl: phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, triphenylene, pyridyl, dibenzofuranyl, dibenzothiophenyl, 9-dimethylfluorenyl, spirofluorenyl, carbazole groups;

ar is selected from dibenzofuran, N-phenyl-carbazole, dibenzothiophene, biphenyl, 9, 9-dimethylfluorene, spirobifluorene, terphenyl, unsubstituted or substituted with deuterium, halogen, phenyl, biphenyl or naphthyl;

the heteroatom of the heteroaryl ring group is selected from O, S and N.

More preferably, the compound is selected from the following compounds:

a second aspect of the present application provides a light extraction material comprising the above compound of the present application.

Fig. 1 shows a schematic view of a typical organic electroluminescent device, in which a substrate 1, a reflective anode electrode 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 electrode 10, and a light extraction layer 11 are sequentially disposed from bottom to top.

It is to be understood that fig. 1 schematically illustrates the structure of a typical organic electroluminescent device, and the present application is not limited to this structure, and the light extraction material of the present application may be used in any type of organic electroluminescent device.

In the organic electroluminescent device, the light extraction layer 10 may employ inorganic compounds and organic compounds or a combination thereof, and the refractive index of the light extraction layer is generally required to be greater than 1.8. The organic compounds used in the prior art are mainly aromatic amine compounds, for example, aromatic amines represented by the following formula:

in addition, as the wavelength of light wave increases, the refractive index of the compound is reduced and the change is large, so that for light with different colors, different thicknesses of light extraction layers are needed to respectively obtain higher light extraction efficiency.

In the organic electroluminescent device, in order to improve the light extraction efficiency, a light extraction layer is generally provided on the electrode on the light extraction side. The refractive index of the light extraction layer is required to be larger than that of the electrode and to transmit visible light. The light extraction material of the present application has a high refractive index and thus can provide a high light extraction rate. Preferably, the refractive index of the light extraction material of the present application is > 1.85.

The light extraction material has small refractive index change along with the increase of the wavelength of light waves, and can obtain more balanced light extraction rate when being used for red light, green light and blue light organic electroluminescent devices and adopting light extraction layers with the same thickness. Preferably, the difference between the refractive index of red light and the refractive index of blue light of the light extraction material of the present application is <0.2, preferably < 0.15. Unless otherwise stated, the difference between the refractive index of red light and the refractive index of blue light described in the context of the present invention is mainly referred to the difference between the refractive index at a red light wavelength of 630nm and the refractive index at a blue light wavelength of 460 nm.

In the organic electroluminescent device, the light extraction layer may be formed by various methods such as vacuum evaporation and spin coating, and is preferably formed by vacuum evaporation. In the vacuum evaporation process, if the evaporation temperature is too high, the organic electroluminescent device may be damaged and high-temperature pyrolysis of the light extraction material may be caused. The evaporation temperature of the light extraction material is 330-400 ℃. The light extraction layer can be well formed by vacuum evaporation and high-temperature pyrolysis is not generated.

A third aspect of the present application provides an organic electroluminescent device comprising at least one of the light extraction materials of the present application as a light extraction layer. There is no limitation in the kind and structure of the organic electroluminescent device in the present application, and various types and structures of organic electroluminescent devices known in the art may be used, in which the light extraction layer of the present application is disposed on the transparent electrode on the light-emitting side.

The organic electroluminescent device of the present invention may be a light-emitting device having a top emission structure, and may include a structure comprising an anode, a hole transport layer, a light-emitting layer, an electron transport layer, a transparent or translucent cathode, and a light extraction layer in this order on a substrate.

The organic electroluminescent element of the present invention may be a light-emitting element having a bottom emission structure, and may include a light-extraction layer, a transparent or translucent anode, a hole-transport layer, a light-emitting layer, an electron-transport layer, and a cathode structure in this order on a substrate.

The organic electroluminescent element of the present invention may be a light-emitting element having a double-sided light-emitting structure, and may include a light-extracting layer, a transparent or semitransparent anode, a hole-transporting layer, a light-emitting layer, an electron-transporting layer, a transparent or semitransparent cathode structure, and a light-extracting layer, which are sequentially formed on a substrate, wherein the light-extracting layer has a thickness of 50 to 90nm, and the light-extracting layer may have a thickness of 3L, 5L, or the like, in consideration of the more general case.

In addition, a hole injection layer may be provided between the anode electrode and the hole transport layer. An electron blocking layer is provided between the hole transport layer and the light emitting layer. A hole blocking layer is provided between the light emitting layer and the electron transport layer. An electron injection layer is provided between the electron transport layer and the cathode electrode. However, the structure of the organic electroluminescent device of the present invention is not limited to the above-described specific structure, and the above-described layers may be omitted or simultaneously provided, if necessary. For example, the organic electroluminescent device may include an anode made of metal, a hole injection layer (5-20nm), a hole transport layer (80-140nm), an electron blocking layer (5-20nm), a light emitting layer (150-400nm), a hole blocking layer (5-20nm), an electron transport layer (300-800nm), an electron injection layer (5-20nm), a transparent or semitransparent cathode, and a light extraction layer structure on a substrate in this order.

In the organic electroluminescent device of the present invention, any material used for the layer as in the prior art can be used for the layer other than the light extraction layer comprising the light extraction material provided by the present invention.

The organic electroluminescent device of the present application is explained below with reference to fig. 1.

In the present application, the substrate 1 is not particularly limited, and a conventional substrate used in the organic electroluminescent device in the related art, for example, glass, polymer material, etc. may be used.

In the present application, the reflective anode electrode 2 is not particularly limited and may be selected from reflective anode electrodes known in the art. For example, metals, alloys or conductive compounds have a high work function (4eV or more than 4 eV). The metal may be Au, Ag, etc. The conductive transparent material can be selected from CuI, Indium Tin Oxide (ITO), SnO₂And ZnO, or an amorphous material such as IDIXO (In) which can form a transparent conductive film₂O₃-ZnO). The thickness of the anode is in the range of 10 to 1,000 nm. Wherein the thickness of the anode varies depending on the material used.

In the present application, the hole injection layer 3 is not particularly limited, and may be made of a hole injection layer material known in the art, for example, an HTM (hole transport material) material is selected as a host material, and a p-type dopant is added. The kind and content of the p-type dopant are not particularly limited, and various p-type dopants and contents thereof known in the art may be employed, for example, the following p-type dopants may be employed:

in the present application, the hole transport layer 4 is not particularly limited, and may be made of a Hole Transport Material (HTM) known in the art. For example, the HTM for the hole injection layer host material and the HTM for the hole transport layer may be selected from the following compounds:

in the present application, the organic electroluminescent device may include an electron blocking layer 5 that transports holes while inhibiting electrons from reaching the hole transport layer. The material of the electron blocking layer 5 is not particularly limited, and any electron blocking material known to those skilled in the art may be used. For example, the following electron blocking materials may be used:

in the present application, the organic electroluminescent device includes a light emitting layer 6, and a light emitting material in the light emitting layer 6 is not particularly limited, and any light emitting material known to those skilled in the art may be used, for example, the light emitting material may include a host material and a guest material. The host material may be selected from the following compounds, which may be used alone or in combination:

in a preferred embodiment of the present application, the light-emitting layer employs the technique of phosphorescent electroluminescence. The guest material in the light-emitting layer is a phosphorescent dopant, which may be selected from, but is not limited to, a combination of one or more of the following compounds. The amount of the phosphorescent dopant is not particularly limited and may be an amount well known in the art.

In the present application, the organic electroluminescent device includes a hole blocking layer 7, and the hole blocking layer 7 blocks the transport of holes while transporting electrons. The material of the hole blocking layer is not particularly limited, and a hole blocking material known in the art may be used, for example, a combination of one or more of the following materials may be used:

in the present application, the organic electroluminescent device comprises an electron transport layer 8, the material of the electron transport layer 8 is not particularly limited, and electron transport materials known in the art may be used, including but not limited to one or more combinations of the materials listed below as ET1-ET 58.

In the present application, the organic electroluminescent device may further include an electron injection layer 9, which may use an electron injection material known in the art, for example, and may include, but is not limited to, the prior artMiddle L iQ, L iF, NaCl, CsF, L i₂O、Cs₂CO₃One or a combination of more of BaO, Na, L i, Ca and the like.

In the present application, the organic electroluminescent device comprises a cathode 9, and the material of the cathode 9 is not particularly limited, and may be selected from, but not limited to, magnesium silver mixture, L iF/Al, metal such as ITO, metal mixture, oxide, and the like.

In the present application, the organic electroluminescent device comprises a light extraction layer 10, the light extraction layer 10 comprising a light extraction material according to the present invention. The light extraction layer may also comprise a combination of the light extraction material of the present invention with known light extraction materials. As described above, currently known light extraction materials are mainly triarylamine-based light extraction materials.

The present application also provides a display device comprising the organic electroluminescent device of the present application. The display device includes, but is not limited to, a display, a television, a mobile communication terminal, a tablet computer, and the like.

The method for preparing the organic electroluminescent device of the present application is not particularly limited, and any method known in the art may be used, for example, the present application may be prepared by the following preparation method:

(1) cleaning a reflective anode electrode 2 on an O L ED device substrate 1 for top emission, respectively performing steps of medicinal washing, water washing, hairbrush, high-pressure water washing, air knife and the like in a cleaning machine, and then performing heat treatment;

(2) a hole injection layer is evaporated on the reflective anode electrode 2 by a vacuum evaporation method, the main material of the hole injection layer is HTM, which contains p-type dopant (p-dopant), and the layer is used as a hole injection layer 3;

(3) vacuum evaporating a Hole Transport Material (HTM) as a hole transport layer 4 on the hole injection layer 3;

(4) an Electron Blocking Material (EBM) is evaporated on the hole transport layer 4 in vacuum to be used as an electron blocking layer 5;

(5) a luminescent layer 6 is vacuum evaporated on the electron barrier layer 5, and the luminescent layer contains a host material and a guest material;

(6) vacuum evaporation of HBM on the light-emitting layer 6 is performed to form a hole blocking layer 7;

(7) vacuum evaporating an Electron Transport Material (ETM) containing an n-type dopant (n-dopant) as an electron transport layer 8 on the hole blocking layer 7;

(8) an electron injection layer 9 is vacuum-deposited on the electron transport layer 8, and the electron injection layer 8 is made of an electron injection material selected from L iQ, L iF, NaCl, CsF, and L i₂O、Cs₂CO₃One or more of BaO, Na, L i, Ca and other electron injection materials;

(9) vacuum evaporation of Mg: an Ag layer, which is a cathode electrode 10;

(10) finally, a light extraction material is vapor-deposited on the cathode electrode 10 as a light extraction layer 11.

The above description has been made only of the structure of a typical organic electroluminescent device and a method for manufacturing the same, and it should be understood that the present application is not limited to this structure. The light extraction material of the present application can be used for an organic electroluminescent device of any structure, and the organic electroluminescent device can be manufactured by any manufacturing method known in the art.

Synthetic examples

L Synthesis of EM 1:

into a reaction flask were charged 100mmol of 1, 3-dibromo-5-chlorobenzene, 220mmol of N-phenylcarbazole-2-boronic acid, 60g of potassium carbonate (500mmol), 800ml of THF and 200ml of water, and 3 mol% of Pd (PPh) was added₃)₄. The reaction was carried out at 65 ℃ for 12 h. After the reaction was completed, the reaction was stopped, and the reaction mixture was cooled to room temperature, water was added, filtered, washed with water, and the obtained solid was purified by recrystallization from toluene to obtain white powder M1. Wherein, Pd (PPh)₃)₄The amount of (A) added was 3 mol% based on 1, 3-dibromo-5-chlorobenzene.

Into a reaction flask were charged 100mmol of M1, 100mmol of dibenzofuran-2-boronic acid, 40g of potassium carbonate (300mmol), 800ml of THF and 200ml of water, and 1 mol% of Pd (PPh) was added₃)₄. At 6Reacting at 5 deg.C for 12h, cooling to room temperature, adding water, filtering, washing with water, recrystallizing the obtained solid with toluene to obtain white powder A1, i.e. L EM1, wherein Pd (PPh)₃)₄Was added in an amount of 1 mol% based on M1. 1H NMR (400MHz, Chloroform) 8.33-8.23 (m,4H),8.19(d, J ═ 7.6Hz,3H),7.99(d, J ═ 8.4Hz,3H), 7.99-7.77 (m,5H),7.69(s,1H),7.62(d, J ═ 8.0Hz,4H),7.58(s,1H), 7.56-7.48 (m,3H), 7.44-7.34 (m,5H),7.31(s,1H), 7.22-7.14 (m, 4H).

L Synthesis of EM 6:

into a reaction flask were charged 100mmol of 1, 3-dibromo-5-chlorobenzene, 220mmol of N-phenylcarbazole-3-boronic acid, 60g of potassium carbonate (500mmol), 800ml of THF and 200ml of water, and 3 mol% of Pd (PPh) was added₃)₄. The reaction was carried out at 65 ℃ for 12 h. After the reaction was completed, the reaction was stopped, and the reaction mixture was cooled to room temperature, water was added, filtered, washed with water, and the obtained solid was purified by recrystallization from toluene to obtain white powder M1. Wherein, Pd (PPh)₃)₄The amount of (A) added was 3 mol% based on 1, 3-dibromo-5-chlorobenzene.

Into a reaction flask were charged 100mmol of M1, 100mmol of dibenzofuran-2-boronic acid, 40g of potassium carbonate (300mmol), 800ml of THF and 200ml of water, and 1 mol% of Pd (PPh) was added₃)₄Reaction at 65 deg.C for 12h, cooling to room temperature, adding water, filtering, washing with water, recrystallizing the obtained solid with toluene to obtain white powder A2, namely L EM6, wherein Pd (PPh)₃)₄Was added in an amount of 1 mol% based on M1.

1H NMR(400MHz,Chloroform)8.29(dd,J＝12.0,8.4Hz,6H),8.19(s,1H),7.92(d,J＝9.6Hz,2H),7.70(d,J＝10.0Hz,4H),7.60(dd,J＝10.0,8.0Hz,6H),7.52(t,J＝10.0Hz,4H),7.39(d,J＝8.0Hz,3H),7.31(s,1H),7.22–7.14(m,7H)。

L Synthesis of EM 46:

into a reaction flask were charged 100mmol of 1, 3-dibromo-5-chlorobenzene, 220mmol of N-phenylcarbazole-3-boronic acid, 60g of potassium carbonate (500mmol), 800ml of THF and 200ml of water, and 3 mol% of Pd (PPh) was added₃)₄. The reaction was carried out at 65 ℃ for 12 h. After the reaction was completed, the reaction was stopped, and the reaction mixture was cooled to room temperature, water was added, filtered, washed with water, and the obtained solid was purified by recrystallization from toluene to obtain white powder M1. Wherein, Pd (PPh)₃)₄The amount of (A) added was 3 mol% based on 1, 3-dibromo-5-chlorobenzene.

Into a reaction flask were charged 100mmol of dibenzofuran-2-boronic acid, 100mmol of p-bromoiodobenzene, 30g of potassium carbonate (500mmol), 800ml of THF and 200ml of water, and 1 mol% of Pd (PPh) was added₃)₄. The reaction was carried out at 65 ℃ for 12 h. After the reaction was completed, the reaction was stopped, and the reaction mixture was cooled to room temperature, water was added, filtered, washed with water, and the obtained solid was purified by recrystallization from toluene to obtain white powder M2. Wherein, Pd (PPh)₃)₄Is added in an amount of 1 mol% based on the p-bromoiodobenzene.

Into a reaction flask were charged 100mmol of M2, 120mmol of pinacol diboron, 30g of potassium carbonate (500mmol), 800ml of dioxane, and 1 mol% of Pd (dppf) Cl₂. The reaction was carried out at 80 ℃ for 12 h. After the reaction was completed, the reaction was stopped, and the reaction mixture was cooled to room temperature, water was added, filtered, washed with water, and the obtained solid was purified by recrystallization from toluene to obtain white powder M3. Wherein Pd (dppf) Cl₂Was added in an amount of 1 mol% based on M2.

Into a reaction flask were charged 100mmol of M1, 100mmol of M3, 40g of potassium carbonate (300mmol), 800ml of THF and 200ml of water, and 1 mol% of Pd (PPh) was added₃)₄Reaction at 65 deg.C for 12h, stopping reaction, cooling to room temperature, adding water, filtering, washing with water, recrystallizing the obtained solid with toluene to obtain white powder A3, namely L EM46, wherein Pd (PPh)₃)₄Was added in an amount of 1 mol% based on M1.

1H NMR(400MHz,Chloroform)8.41–8.12(m,6H),7.92(d,J＝8.0Hz,2H),7.70(d,J＝10.0Hz,2H),7.61(dd,J＝10.0,8.0Hz,4H),7.52(t,J＝10.0Hz,5H),7.39(d,J＝8.0Hz,2H),7.31-7.25(m,9H),7.22–7.14(m,8H)。

L Synthesis of EM 96:

into a reaction flask were charged 100mmol of dibenzofuran-2-boronic acid, 100mmol of m-bromoiodobenzene, 30g of potassium carbonate (500mmol), 800ml of THF and 200ml of water, and 1 mol% of Pd (PPh) was added₃)₄. The reaction was carried out at 65 ℃ for 12 h. After the reaction was completed, the reaction was stopped, and the reaction mixture was cooled to room temperature, water was added, filtered, washed with water, and the obtained solid was purified by recrystallization from toluene to obtain white powder M1. Wherein, Pd (PPh)₃)₄The addition amount of (A) is 1 mol% of the m-bromoiodobenzene.

Into a reaction flask were charged 100mmol of M1, 120mmol of pinacol diboron, 30g of potassium carbonate (500mmol), 800ml of dioxane, and 1 mol% of Pd (dppf) Cl₂. The reaction was carried out at 80 ℃ for 12 h. After the reaction was completed, the reaction was stopped, and the reaction mixture was cooled to room temperature, water was added, filtered, washed with water, and the obtained solid was purified by recrystallization from toluene to obtain white powder M2. Wherein Pd (dppf) Cl₂Was added in an amount of 1 mol% based on M1.

Into a reaction flask were charged 100mmol of 1, 3-dibromo-5-chlorobenzene, 220mmol of M2, 60g of potassium carbonate (500mmol), 800ml of THF and 200ml of water, and 3 mol% of Pd (PPh) was added₃)₄. The reaction was carried out at 65 ℃ for 12 h. After the reaction was completed, the reaction was stopped, and the reaction mixture was cooled to room temperature, water was added, filtered, washed with water, and the obtained solid was purified by recrystallization from toluene to obtain white powder M3. Wherein, Pd (PPh)₃)₄The amount of (A) added was 3 mol% based on 1, 3-dibromo-5-chlorobenzene.

Into a reaction flask were charged 100mmol of M3, 100mmol of 9, 9-dimethylfluorene-2-boronic acid, 40g of potassium carbonate (300mmol), 800ml of THF and 200ml of water, and 1 mol% of Pd (PPh) was added₃)₄. The reaction was carried out at 65 ℃ for 12 h. Stopping the reaction after the reaction is finished, and reactingCooling the reaction mixture to room temperature, adding water, filtering, washing with water, and recrystallizing the obtained solid with toluene to obtain white powder A4, i.e. L EM96, wherein Pd (PPh)₃)₄Was added in an amount of 1 mol% based on M3. 1H NMR (400MHz, Chloroform) 8.28-8.19 (m,5H),8.09(s,1H),8.04(s,1H),7.98-7.90(m,5H),7.78-7.71(m,3H), 7.71-7.43 (m,11H),7.39(s,1H),7.33(d, J ═ 12.4Hz,4H),7.24(s,1H),1.69(s, 6H).