Heteroaryl-containing bisindole compound as well as preparation method and application thereof

Abstract

The invention relates to a heteroaryl-containing bisindole compound as well as a preparation method and application thereof, the structure of the bisindole compound comprises Ar1 and Ar2, and at least one of Ar1 and Ar2 is selected from an oxygen-containing, nitrogen-containing or sulfur-containing heterocyclic ring; the preparation method of the bisindole compound comprises the following steps: preparing an intermediate M1, and then synthesizing the heteroaryl-containing bisindole compound; applying the heteroaryl-containing bisindole compound to an organic electroluminescent device, according to the present invention, the structure of the bisindole compound is designed, such that the bisindole compound can be used as the main body material of the organic electroluminescent device light-emitting layer, and the prepared organic electroluminescent device has characteristics of high current efficiency and long service life.

Description

Technical Field

[0001] The present invention belongs to the technical field related to new materials, and specifically relates to a bisindole compound containing a heteroaryl group, and a preparation method and application thereof. Background Art

[0002] The structure of an organic electroluminescent device (OLED for short) is specifically: an anode, a cathode, and an organic thin film layer between the anode and the cathode. In order to improve the efficiency and stability of the organic electroluminescent device, the organic material layer includes multiple layers with different materials, such as a hole injection layer (HIL), a hole transport layer (HTL), a light-emitting layer, an electron transport layer (ETL), an electron injection layer (EIL), an electron blocking layer, etc.

[0003] In order to improve the performance of organic electroluminescent devices, various new OLED materials have also been developed. However, their various performances need to be improved, especially in terms of current efficiency and lifespan. In order to meet people's higher requirements for OLED devices, the field urgently needs to develop more types of OLED materials with higher performance. Summary of the invention

[0004] The object of the present invention is to provide a bisindole compound which is suitable for being used as a main material of a light-emitting layer of an organic electroluminescent device by designing its structure, and the organic electroluminescent device prepared thereby has a higher current efficiency and a longer lifespan.

[0005] To achieve the above object, the present invention provides the following technical solution: a bisindole compound containing a heteroaryl group and a preparation method and application thereof, wherein the compound has a structure shown in the following formula I:

[0006]

[0007] Formula I wherein at least one of Ar1 and Ar2 is selected from an oxygen-containing, nitrogen-containing or sulfur-containing heterocycle; the hydrogen atoms in the compound represented by Formula I are substituted by at least one of -D, -F, -CN, C6-C20 aryl, C6-C20 heteroaryl, C1-C20 alkyl, and C1-C20 alkoxy.

[0008] As a further improvement of the present invention, Ar1 and Ar2 are each independently selected from C6-C40 aromatic groups; the C6-C40 aromatic groups are selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, fluorenyl, benzofluorenyl, dibenzofluorenyl, naphthfluoroenyl, pyrene, perylenyl, spirofluorenyl, triphenylene, fluoranthenyl, hydrogenated benzanthryl, indenofluorenyl, benzoindenofluorenyl, dibenzoindenofluorenyl, naphthfluoroenyl or benzonaphthofluorenyl.

[0009] As a further improvement of the present invention, Ar1 and Ar2 are each independently selected from a C6-C30 heteroaryl group; the C6-C30 heteroaryl group is selected from any one of dibenzofuranyl, dibenzothiophenyl, benzodibenzofuranyl, benzodibenzothiophenyl, dibenzocarbazolyl, pyridyl and quinolyl.

[0010] As a further improvement of the present invention, Ar1 and Ar2 are each independently selected from any one of phenyl, biphenyl, 9,9-dimethylfluorenyl, naphthyl, triphenylene, fluoranthene, phenanthryl, dibenzofuranyl, dibenzothiophenyl, naphthodibenzofuranyl, naphthodibenzothiophenyl, dibenzocarbazolyl, pyridyl, and quinolyl.

[0011] As a further improvement of the present invention, the hydrogen atoms in the heteroaryl-containing bisindole compounds can be replaced by at least one of -D, -F, -CN, phenyl, naphthyl, biphenyl, fluorenyl, dibenzofuran, dibenzothiophene, methyl, ethyl, propyl, butyl, cyclohexyl, adamantyl, methoxy, ethoxy, propoxy, and butoxy.

[0012] As a further improvement of the present invention, the heteroaryl-containing bisindole compound is selected from any one of the following chemical structures:

[0013]

[0014]

[0015] A method for preparing a bisindole compound containing a heteroaryl group comprises the following steps: a first step of preparing an intermediate M1, wherein the preparation reaction process is as follows:

[0016]

[0017] The specific preparation steps include: adding dry toluene,

[0018] 2-Chloro-10,10-methyl-9,11-diphenyl-10,11-dihydro-9H-benzo[6,7]cycloheptane[2,1-b:

[0019] 4,5-b']diindole, bipyraclostrobin, PdCl2(PPh3), KOAc, heated to reflux, after reaction, cooled to room temperature and then separated by adding water; then the organic layer was washed with water until neutral, dried with magnesium sulfate, filtered to remove magnesium sulfate, concentrated to dryness, separated by silica gel column chromatography, eluted with a solvent of petroleum ether: ethyl acetate = 50:1 by volume, to obtain intermediate M1;

[0020] The second step is to synthesize bisindole compounds containing heteroaryl groups. The synthesis reaction formula is as follows:

[0021]

[0022] The specific synthetic reaction steps include: under nitrogen protection, adding dioxane and water in a three-necked flask in sequence, then adding intermediate M1, 9-[2-(4-chloro-6-phenyl-1,3,5-triazine)-9H-carbazole, sodium carbonate and tetrakistriphenylphosphine palladium, slowly heating up to reflux reaction; cooling to room temperature, adding water and toluene for separation, washing the organic layer with water, drying with magnesium sulfate, removing the desiccant; concentrating to dryness, and crystallizing twice with toluene to obtain the final compound.

[0023] The heteroaromatic-containing bisindole compound is applied to an organic electroluminescent device, which comprises an anode, a cathode and an organic thin film layer arranged between the anode and the cathode; the light-emitting layer in the organic thin film layer comprises the heteroaromatic-containing bisindole compound.

[0024] As a further improvement of the present invention, the organic electroluminescent device is a phosphorescent organic electroluminescent device; the light-emitting layer includes a light-emitting layer main material and a doping material, wherein the doping material is a dye or a phosphorescent light-emitting material; the light-emitting layer main material is a single compound, or a mixture of two or more compounds.

[0025] As a further improvement of the present invention, the luminescent layer includes a phosphorescent luminescent layer, and the phosphorescent luminescent layer includes a green phosphorescent luminescent layer, a red phosphorescent luminescent layer, and a yellow phosphorescent luminescent layer; the volume percentage of the phosphorescent luminescent layer in the main material is 60%-99.9%.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: the technical solution designs the structure of the bisindole compound to make it suitable as the main material of the light-emitting layer of the organic electroluminescent device, and the organic electroluminescent device prepared thereby has higher current efficiency and longer service life. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention are described clearly and completely below. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Preparation Example 1:

[0029] This preparation example provides an intermediate M1 and a synthesis method thereof, and the synthesis method is as follows:

[0030]

[0031] Under nitrogen protection, 200 mL of dry toluene, 2-chloro-10,10-methyl-9,11-diphenyl-10,11-dihydro-9H-benzo[6,7]cycloheptane[2,1-b:4,5-b']diindole (5.35 g), biboronic acid pinacol ester (5.8 g), PdCl2(PPh3) (0.05 g), KOAc (0.1 g) were added to a 500 mL three-necked flask, heated to reflux, reacted for 18 hours, cooled to room temperature, and then water was added to separate, and then the organic layer was washed with water until neutral, dried with magnesium sulfate, filtered to remove magnesium sulfate, concentrated to dryness, separated by silica gel column chromatography, and eluted with a solvent of petroleum ether: ethyl acetate = 50:1 (volume ratio) to obtain 4.1 g of intermediate M1. The intermediate M1 was detected by mass spectrometry: the mass-to-charge ratio (m / z) was 626.31.

[0032] Synthesis Example 1:

[0033] This synthesis example provides a bisindole compound P1 and a synthesis method thereof, and the synthesis method is as follows:

[0034]

[0035] Under nitrogen protection, 200 ml of dioxane and 60 ml of water were added to a 500 ml three-necked flask in sequence, and then intermediate M1 (6.2 g), 9-[2-(4-chloro-6-phenyl-1,3,5-triazine)-9H-carbazole (2.3 g), sodium carbonate (2.3 g) and tetrakistriphenylphosphine palladium (0.05 g) were added thereto, and the temperature was slowly raised to reflux for reaction for 15 h, and the temperature was lowered to room temperature, and water and toluene were added for separation. The organic layer was washed with water, dried with magnesium sulfate, and after removing the desiccant, it was concentrated to dryness and crystallized from toluene twice to obtain 3.2 g of compound P1. Compound P1 was detected by mass spectrometry: the mass-to-charge ratio (m / z) was measured to be 820.33.

[0036] Synthesis Example 2-11:

[0037] Synthesis Examples 2-11 respectively provide a bisindole compound and a synthesis method thereof. The synthesis method refers to the synthesis method provided in Synthesis Example 1, with the only difference being that 2-chloro-4,6-diphenyl-1,3,5-triazine is replaced by different types of triazine compounds in equal amounts (see Table 2 for details), and the final bisindole compounds are subjected to mass spectrometry detection, and the mass-to-charge ratios (m / z) are measured as shown in Table 1.

[0038] Table 1: Mass spectrometry detection table

[0039]

[0040]

[0041]

[0042] The synthesis methods of the compounds not listed can refer to the above embodiments and the common methods in the art.

[0043] Application Example 1:

[0044] This application example provides a red organic electroluminescent device, and the light-emitting layer structure of the red organic electroluminescent device is ITO / HT-1:PD-1[3%](20nm) / HT-1(40nm) / EB-1(20nm) / main material: RD-1[8%](35nm) / ET-1[50%]:ET2[50%](300nm) / LiF(0.5nm) / Al(150nm).

[0045] The preparation method of the red organic electroluminescent device is as follows: placing the material in a vacuum chamber, evacuating the vacuum to 1×10-5-1×10-6Pa, and vacuum evaporating the material onto a cleaned ITO conductive glass substrate in sequence to prepare an OLED device.

[0046] Among them: HT-1 is a hole transport material. RD-1 [8%] refers to the doping ratio of the dye, that is, the volume ratio of the main material to the dye RD-1 is 92:8. HT-1: PD-1 [3%] refers to the ratio of the P-type dopant, that is, the volume ratio of the hole material HT-1 and the P-type dopant PD-1 is 97:3. HT-1: PD-1 [3%] is used as a hole injection layer. The full name of EB dye is ethidium bromide, which is a highly sensitive fluorescent dye. ET dye is a type of solvatochromic dye. LiF is a lithium fluoride (LiF) material. Al is aluminum metal, and its complex can produce chemiluminescence. The complex formed by the ligand and the metal atom or ion through coordination bonds is called a metal complex. Nm is the unit nanometer. The main material of the light-emitting layer in this application example is the bisindole compound P1.

[0047] Application examples 2 to 11:

[0048] Application Examples 2 to 11 respectively provide a red organic electroluminescent device, which differs from Application Example 1 only in that the main material of the light-emitting layer, the bisindole compound P1, is replaced by other bisindole compounds (see Table 2 for details), and the other preparation steps and conditions are the same as those of Application Example 1.

[0049] Comparative Example 1:

[0050] Comparative Example 1 provides an organic electroluminescent device, which is different from Application Examples 1 to 11 only in that the main material of the light-emitting layer is replaced with other compounds (non-bisindole compounds), and the other preparation steps and conditions are the same as those of Application Example 1.

[0051] Performance test analysis: The current efficiency and service life of the existing conventional main material application H-1 and the above application examples were tested. The life test of the organic light-emitting material uses a constant current to apply to the OLED device, and then distinguishes its life according to the target value of brightness reduction. The LT95 test is the time from the initial brightness of 100% to 95%. The test results are shown in Table 2:

[0052] Table 2: Performance test parameter comparison table

[0053] Application Examples Main material <![CDATA[Luminance / (cd / m 2 )]]> Current efficiency / (cd / A) LT95 / (h) Comparative Example 1 H-1 1000 18.0 69 Application Example 1 P1 1000 31.4 83 Application Example 2 P2 1000 33.5 89 Application Example 3 P3 1000 32.8 111 Application Example 4 P4 1000 29.3 72 Application Example 5 P5 1000 31.7 91 Application Example 6 P6 1000 32.7 107 Application Example 7 P7 1000 32.7 78 Application Example 8 P8 1000 29.4 131 Application Example 9 P9 1000 26.6 143 Application Example 10 P10 1000 23.7 124 Application Example 11 P11 1000 25.8 99

[0054] From the comparison of the contents in Table 2, it can be seen that in the present invention, by using the bisindole compound with a designed structure as the main material of the light-emitting layer of the red organic electroluminescent device, the current efficiency and service life of the organic electroluminescent device can be effectively improved.

[0055] The present invention illustrates the detailed process flow of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process flow to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A bisindole compound containing a heteroaryl group, characterized in that: The compound has the structure shown in the following formula I: Formula I wherein at least one of Ar1 and Ar2 is selected from an oxygen-containing, nitrogen-containing or sulfur-containing heterocycle; the hydrogen atoms in the compound represented by Formula I are substituted by at least one of -D, -F, -CN, C6-C20 aryl, C6-C20 heteroaryl, C1-C20 alkyl, and C1-C20 alkoxy.

2. A bisindole compound containing a heteroaryl group according to claim 1, characterized in that: Ar1 and Ar2 are each independently selected from C6-C40 aromatic groups; the C6-C40 aromatic groups are selected from any one of phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, fluorenyl, benzofluorenyl, dibenzofluorenyl, naphthfluoroenyl, pyrene, perylenyl, spirofluorenyl, triphenylene, fluoranthenyl, hydrogenated benzanthryl, indenofluorenyl, benzoindenofluorenyl, dibenzoindenofluorenyl, naphthfluoroenyl or benzonaphthofluorenyl.

3. A bisindole compound containing a heteroaryl group according to claim 1, characterized in that: Ar1 and Ar2 are each independently selected from C6-C30 heteroaryl; the C6-C30 heteroaryl is selected from any one of dibenzofuranyl, dibenzothiophenyl, benzodibenzofuranyl, benzodibenzothiophenyl, dibenzocarbazolyl, pyridyl and quinolyl.

4. A bisindole compound containing a heteroaryl group according to claim 1, characterized in that: Ar1 and Ar2 are each independently selected from any one of phenyl, biphenyl, 9,9-dimethylfluorenyl, naphthyl, triphenylene, fluoranthene, phenanthryl, dibenzofuranyl, dibenzothiophenyl, naphthodibenzofuranyl, naphthodibenzothiophenyl, dibenzocarbazolyl, pyridyl, and quinolyl.

5. A bisindole compound containing a heteroaryl group according to claim 1, characterized in that: The hydrogen atoms in the heteroaryl-containing bisindole compound can be substituted by at least one of -D, -F, -CN, phenyl, naphthyl, biphenyl, fluorenyl, dibenzofuran, dibenzothiophene, methyl, ethyl, propyl, butyl, cyclohexyl, adamantyl, methoxy, ethoxy, propoxy, and butoxy.

6. A bisindole compound containing a heteroaryl group according to claim 1, characterized in that: The heteroaryl-containing bisindole compound is selected from any one of the following chemical structures:

7. A method for preparing a bisindole compound containing a heteroaryl group as claimed in any one of claims 1 to 6, characterized in that: The first step is to prepare intermediate M1. The preparation reaction process is as follows: The specific preparation steps include: under nitrogen protection, adding dry toluene, 2-chloro-10,10-methyl-9,11-diphenyl-10,11-dihydro-9H-benzo[6,7]cycloheptane[2,1-b: 4,5-b']diindole, bipyraclostrobin, PdCl2(PPh3), KOAc, heated to reflux, After the reaction, the temperature was lowered to room temperature and water was added to separate the mixture; the organic layer was then washed with water until neutral, dried with magnesium sulfate, filtered to remove the magnesium sulfate, concentrated to dryness, separated by silica gel column chromatography, and eluted with a solvent of petroleum ether: ethyl acetate = 50:1 by volume to obtain intermediate M1; The second step is to synthesize bisindole compounds containing heteroaryl groups. The synthesis reaction formula is as follows: The specific synthetic reaction steps include: under nitrogen protection, adding dioxane and water in a three-necked flask in sequence, then adding intermediate M1, 9-[2-(4-chloro-6-phenyl-1,3,5-triazine)-9H-carbazole, sodium carbonate and tetrakistriphenylphosphine palladium, slowly heating up to reflux reaction; cooling to room temperature, adding water and toluene for separation, washing the organic layer with water, drying with magnesium sulfate, removing the desiccant; concentrating to dryness, and crystallizing twice with toluene to obtain the final compound.

8. Use of a bisindole compound containing a heteroaryl group as claimed in any one of claims 1 to 6, characterized in that: The heteroaromatic bisindole compound according to claims 1-6 is applied to an organic electroluminescent device, wherein the organic electroluminescent device comprises an anode, a cathode and an organic thin film layer arranged between the anode and the cathode; the light-emitting layer in the organic thin film layer comprises the heteroaromatic bisindole compound according to any one of claims 1-6.

9. The use of a heteroaryl-containing bisindole compound according to claim 8, characterized in that: The organic electroluminescent device is a phosphorescent organic electroluminescent device; the luminescent layer includes a luminescent layer main material and a doping material, wherein the doping material is a dye or a phosphorescent luminescent material; the luminescent layer main material is a single compound or a mixture of two or more compounds.

10. The use of a heteroaryl-containing bisindole compound according to claim 9, characterized in that: The luminescent layer comprises a phosphorescent luminescent layer, and the phosphorescent luminescent layer comprises a green phosphorescent luminescent layer, a red phosphorescent luminescent layer, and a yellow phosphorescent luminescent layer; the volume percentage of the phosphorescent luminescent layer in the main material is 60%-99.9%.

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