Silicon-containing compound and application thereof

Abstract

The invention provides a silicon-containing compound and application thereof, and the silicon-containing compound has a structure as shown in a formula I. The silicon-containing compound has good luminescence performance, can be used for preparing an organic electroluminescent device, and especially can be used as an electron transport layer material in the organic electroluminescent device. The current efficiency of the organic light-emitting device can be effectively improved, and the service life of the organic light-emitting device is prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of organic photoelectric materials, and specifically relates to a silicon-containing compound and application thereof. Background Art

[0002] Organic Light-Emitting Diode (OLED) has the advantages of light weight, small size, wide viewing angle, fast response, wide operating temperature range, low energy consumption, high efficiency, good color purity, high clarity, and good flexibility. It can meet consumers' new demands for display technology and has good application prospects in the fields of lighting and display.

[0003] An organic electroluminescent element is a self-luminous element that utilizes the following principle: by applying an electric field, the fluorescent substance emits light by utilizing the recombination energy of holes injected from the anode and electrons injected from the cathode. It has the following structure: an anode, a cathode, and an organic material layer between the two. In order to improve the efficiency and stability of the organic electroluminescent element, the organic material layer generally 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, and an electron injection layer EIL. In such an organic light-emitting element, when a voltage is applied between the anode and the cathode, holes from the anode and electrons from the cathode are injected into the organic material layer, and the generated excitons generate light with a specific wavelength when they migrate to the ground state. The hole transport layer can change the hole transfer efficiency, light-emitting efficiency, life, etc. of holes to the light-emitting layer.

[0004] At present, the research on organic electroluminescent materials has been widely carried out in academia and industry. Designing and finding a compound as a new OLED material to overcome its shortcomings in practical applications is the focus of OLED material research and the future development trend. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide a silicon-containing compound and its application.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In one aspect, the present invention provides a silicon-containing compound having a structure as shown in the following formula I:

[0008]

[0009] Wherein, R1 and R2 are independently selected from any one or a combination of at least two of C1-C12 alkyl, C1-C12 alkoxy, C6-C30 aryl or C3-C30 heteroaryl;

[0010] L1 is selected from any one of a C6-C30 arylene group or a C3-C30 heteroarylene group;

[0011] n is an integer selected from 0-1.

[0012] In the present invention, the C1-C12 alkane group is selected from methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, tert-pentyl, n-hexyl, cyclohexyl and the like.

[0013] In the present invention, the C1-C12 alkoxy group is selected from methoxy, ethoxy, propoxy, isopropoxy, butoxy, tert-butoxy and the like.

[0014] The C6-C30 aryl group is selected from phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, indenylfluorenyl, perylenyl, phenanthrenyl, pyrenyl, fluoranthenyl or triphenylenyl.

[0015] The C6-C30 arylene group is selected from phenylene, biphenylene, terphenylene, naphthylene, anthracene, indenylene, fluorenylene, perylene, phenanthrenyl, pyrenylene, fluoranthenylene or triphenylene, etc.

[0016] The hetero atom in the C3-C30 heteroaryl group is an oxygen, sulfur and nitrogen atom.

[0017] The C3-C30 heteroaryl group is selected from benzofuran, benzothiophene, pyridine, dibenzofuran, pyrimidine, dibenzothiophene, carbazole, diarylideneamine, benzofurancarbazole, benzofuranthiophene or triazine.

[0018] The C3-C30 heteroarylene group is selected from benzofuranylene, benzothiopheneylene, pyridineylene, dibenzofuranylene, pyrimidineylene, dibenzothiopheneylene, carbazoleylene, diarylamineylene, benzofuranocarbazoleylene, benzofuranothiopheneylene or triazineylene.

[0019] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0020] As a preferred technical solution of the present invention, the silicon-containing compound includes any one of the following compounds:

[0021]

[0022]

[0023] Preferably, the compound represented by formula I is selected from any one of compounds 1 to 12:

[0024]

[0025] The present invention lists some specific structural forms of the silicon-containing compounds, but the silicon-containing compounds of the present invention are not limited to these listed chemical structures. All structures based on the structure shown in Formula I and in which R1, R2, and L1 meet the above-mentioned limiting conditions should be included.

[0026] In a second aspect, the present invention provides an organic electroluminescent device, wherein the organic electroluminescent device comprises the silicon-containing compound as described in the first aspect.

[0027] Preferably, the organic electroluminescent device comprises a first electrode, a second electrode and an organic layer disposed between the first electrode and the second electrode; the material of the organic layer comprises the silicon-containing compound as described in the first aspect.

[0028] Preferably, the organic layer includes an electron transport layer; the material of the electron transport layer includes the silicon-containing compound as described in the first aspect.

[0029] In a third aspect, the present invention provides a display device, comprising the organic electroluminescent device as described in the second aspect.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention designs the structure of the silicon-containing compound to obtain a silicon-containing compound, which can be used as an electron transport layer material in an organic electroluminescent device, and can effectively improve the current efficiency of the organic electroluminescent device and increase the life of the organic electroluminescent device. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0033] Synthesis Example 1

[0034] This embodiment provides a method for synthesizing compound 1, as described below:

[0035]

[0036] (1) Synthesis of intermediate 1-a

[0037] 2-Bromo-9-(4-chlorophenyl)-9-phenyl-9H-fluorene (100 mmol), 2-nitrobenzeneboronic acid pinacol ester (100 mmol), tetrakis(triphenylphosphine)palladium 1 mmol, potassium carbonate (120 mmol), water 50 mL, dioxane 300 mL, were added to a reaction bottle, refluxed for 4 h under nitrogen protection, cooled after the reaction was complete, toluene was added for separation, washed with water, the organic layer was spin-dried, and the obtained solid was recrystallized with a mixed solvent of toluene and ethanol to obtain intermediate 1-a.

[0038] The mass spectrum data of intermediate 1-a was tested, and the mass spectrum m / z was measured to be 473.12.

[0039] (2) Synthesis of intermediate 1-b

[0040] The intermediate 1-a (40 mmol), (triphenylsilyl)boric acid (40 mmol), dichlorodi-tert-butyl-(4-dimethylaminophenyl)phosphine palladium (II) (0.4 mmol), potassium carbonate (60 mmol) and 300 mL of toluene were added to a reaction flask and heated to reflux for 8 h. The reaction was monitored to be complete by TLC. After filtration with diatomaceous earth, purified water was added to wash until neutral. The organic phase was concentrated and the obtained solid was recrystallized with a mixed solvent of toluene and ethanol to obtain the intermediate 1-b.

[0041] The mass spectrum data of intermediate 1-b was tested, and the mass spectrum m / z was measured to be 697.24.

[0042] (3) Synthesis of intermediate 1-c

[0043] The intermediate 1-b (50 mmol), triphenylphosphine (100 mmol) and o-dichlorobenzene 150 mL were added to the reaction bottle, and the reaction was refluxed for 6 h under nitrogen protection. After the reaction was complete, o-dichlorobenzene was directly distilled out, and the residue was dissolved in toluene and purified by column chromatography. The solid obtained after the column liquid was dried was recrystallized with a mixed solvent of toluene and ethanol to obtain 1-c.

[0044] The mass spectrum data of intermediate 1-c was tested, and the mass spectrum m / z was measured to be 665.25.

[0045] (4) Synthesis of Compound 1

[0046] Intermediate 1-c (30 mmol), 2-bromo-4,6-diphenyl-1,3,5-triazine (30 mmol), cesium carbonate (60 mmol) and DMF (300 mL) were added to a reaction bottle and heated to reflux for 12 h. The reaction was completed after monitoring by TLC. The reaction solution was poured into water and the solid was filtered. The filter cake was washed with ethanol and recrystallized from toluene to obtain compound 1.

[0047] The mass spectrum data of compound 1 was tested, and the mass spectrum m / z was measured to be 896.33.

[0048] Synthesis example 2

[0049] Synthesis of compound 4:

[0050]

[0051] (1) Synthesis of intermediate 4-a

[0052] 4-Bromo-9-(3-chlorophenyl)9-phenyl-9H-fluorene (100mmol), 2-nitrobenzeneboronic acid pinacol ester (100mmol), tetrakis(triphenylphosphine)palladium 1mmol, potassium carbonate (120mmol), 50mL of water, and 300mL of dioxane were added to a reaction bottle and refluxed for 4h under nitrogen protection. After the reaction was complete, the temperature was lowered, toluene was added for separation, the mixture was washed with water, the organic layer was spin-dried, and the obtained solid was recrystallized from a mixed solvent of toluene and ethanol to obtain intermediate 4-a.

[0053] The mass spectrum data of intermediate 4-a was tested, and the mass spectrum m / z was measured to be 473.12.

[0054] (2) Synthesis of intermediate 4-b

[0055] The intermediate 4-a (40 mmol), (triphenylsilyl) boronic acid (40 mmol), dichlorodi-tert-butyl-(4-dimethylaminophenyl) phosphine palladium (II) (0.4 mmol), potassium carbonate (60 mmol), and 300 mL of toluene were added to a reaction flask and heated to reflux for 8 h. The reaction was monitored to be complete by TLC. After filtration with diatomaceous earth, purified water was added to wash until neutral. The organic phase was concentrated, and the obtained solid was recrystallized with a mixed solvent of toluene and ethanol to obtain the intermediate 4-b.

[0056] The mass spectrum data of intermediate 4-b was tested, and the mass spectrum m / z was measured to be 697.24.

[0057] (3) Synthesis of intermediate 4-c

[0058] The intermediate 4-b (50 mmol), triphenylphosphine (100 mmol) and o-dichlorobenzene 150 mL were added to the reaction bottle, and the reaction was refluxed for 6 h under nitrogen protection. After the reaction was complete, o-dichlorobenzene was directly distilled out, and the residue was dissolved in toluene and purified by column chromatography. The solid obtained after the column liquid was dried was recrystallized with a mixed solvent of toluene and ethanol to obtain 4-c.

[0059] The mass spectrum data of intermediate 4-c was tested, and the mass spectrum m / z was measured to be 665.25.

[0060] (4) Synthesis of Compound 4

[0061] Intermediate 4-c (30 mmol), 2-bromo-4,6-diphenyl-1,3,5-triazine (30 mmol), cesium carbonate (60 mmol) and DMF (300 mL) were added to a reaction bottle and heated to reflux for 12 h. The reaction was completed after monitoring by TLC. The reaction solution was poured into water and filtered. The filter cake was washed with ethanol and recrystallized from toluene to obtain compound 4.

[0062] The mass spectrum data of compound 4 was tested and the mass spectrum m / z was measured to be 896.33.

[0063] Synthesis example 3

[0064] Synthesis of compound 6:

[0065]

[0066] Referring to the synthesis method of compound 1, 2-bromo-4-(dibenzofuran-4-yl)-6-phenyl-1,3,5-triazine was used to replace the 2-bromo-4,6-diphenyl-1,3,5-triazine in Synthesis Example 1, and compound 6 was obtained while keeping other conditions unchanged.

[0067] The mass spectrum data of compound 6 was tested and the mass spectrum m / z was measured to be 986.34.

[0068] Synthesis example 4

[0069] Synthesis of compound 9:

[0070]

[0071] Referring to the synthesis method of compound 1, 2-(4-bromophenyl)-4,6-diphenyl-1,3,5-triazine was used to replace the 2-bromo-4,6-diphenyl-1,3,5-triazine in Synthesis Example 1, and compound 9 was obtained while keeping other conditions unchanged.

[0072] The mass spectrum data of compound 9 was tested, and the mass spectrum m / z was measured to be 972.36.

[0073] Synthesis example 5

[0074] Synthesis of compound 10:

[0075]

[0076] Referring to the synthesis method of compound 1, 2-(3-bromophenyl)-4,6-diphenyl-1,3,5-triazine was used to replace the 2-bromo-4,6-diphenyl-1,3,5-triazine in Synthesis Example 1, and compound 10 was obtained while keeping other conditions unchanged.

[0077] The mass spectrum data of compound 10 was tested, and the mass spectrum m / z was measured to be 972.36.

[0078] Synthesis example 6

[0079] Synthesis of compound 11:

[0080]

[0081] Referring to the synthesis method of compound 1, 2-[4-(4-bromophenyl)phenyl]-4,6-diphenyl-1,3,5-triazine is used to replace the 2-bromo-4,6-diphenyl-1,3,5-triazine in Synthesis Example 1, and compound 11 can be obtained while keeping other conditions unchanged.

[0082] The mass spectrum data of compound 11 was tested, and the mass spectrum m / z was measured to be 1048.40.

[0083] Synthesis Example 7

[0084] Synthesis of compound 12:

[0085]

[0086] Referring to the synthesis method of compound 1, 2-(6-bromonaphthalene-2-yl)-4,6-diphenyl-1,3,5-triazine is used to replace the 2-bromo-4,6-diphenyl-1,3,5-triazine in Synthesis Example 1, and compound 12 can be obtained while keeping other conditions unchanged.

[0087] The mass spectrum data of compound 12 was tested, and the mass spectrum m / z was measured to be 1022.38.

[0088] Other compounds whose specific synthesis steps are not listed can be prepared by common knowledge in the art in combination with the above embodiments.

[0089] Device Example 1

[0090] The examples use the compounds of the present application as electron transport materials in organic electroluminescent devices, and the comparative examples use E1 to E3 as electron transport materials in organic electroluminescent devices.

[0091] The structure of the organic electroluminescent device is: ITO / NPB (40nm) / EM1 (30nm) / electron transport material (30nm) / LiF (0.5nm) / Al (150nm).

[0092] The preparation process of organic electroluminescent device is as follows:

[0093] The glass substrate coated with an ITO transparent conductive layer (as an anode) is ultrasonically treated in a cleaning agent, then rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone and ethanol, baked in a clean environment until the water is completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam to improve the properties of the surface and enhance the binding ability with the hole injection layer;

[0094] The glass substrate was placed in a vacuum chamber and evacuated to 1×10 -6 ~9×10 -5 Pa, vacuum evaporate NPB on the anode as a hole transport layer, the evaporation rate is 0.1nm / s, and the evaporation film thickness is 40nm;

[0095] Vacuum evaporate EM1 on the hole transport layer as the organic light-emitting layer of the device, with an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 30 nm;

[0096] A comparative compound and a compound of the present invention are vacuum-deposited on the organic light-emitting layer as an electron transport layer of an organic electroluminescent device; the evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 30 nm;

[0097] 0.5 nm of LiF and 150 nm of Al were vacuum-deposited on the electron transport layer to serve as an electron injection layer and a cathode.

[0098] The material structure used in the device is as follows:

[0099]

[0100] The brightness, driving voltage, current efficiency and life test LT90 of the prepared organic electroluminescent device were measured.

[0101] Device Examples 2-7

[0102] Device Examples 2-7 respectively provide an organic electroluminescent device, which differs from Device Example 1 only in that the electron transport material is different (see Table 1 below for details), and other conditions are the same as those of Device Example 1.

[0103] Device Comparison Examples 1-3

[0104] Device Comparative Examples 1-3 respectively provide an organic electroluminescent device, which is different from Device Example 1 only in that the electron transport material is different (see Table 1 below for details), and other conditions are the same as those of Device Example 1.

[0105] Performance Testing

[0106] Test method: Test the driving voltage, current efficiency and life LT90 of the OLED devices provided above; LT90 refers to the time required for the brightness to drop to 90% of the original brightness while maintaining the current density at the initial brightness of 1000nit. The test items include the brightness, driving voltage and current efficiency of the organic electroluminescent device. The driving voltage, current efficiency and LT90 data are all based on a brightness of 1000cd / m 2 The relative value of the organic electroluminescent device performance test results are shown in the following Table 1.

[0107] Table 1

[0108] Electron transport materials <![CDATA[Required brightness cd / m 2 > Current efficiency cd / A LT90 / h Device Comparison Example 1 E1 1000 1 1 Device Comparison Example 2 E2 1000 0.97 0.99 Device Comparison Example 3 E3 1000 1.03 0.98 Device Example 1 1 1000 1.31 1.59 Device Example 2 4 1000 1.14 2.87 Device Example 3 6 1000 1.17 2.97 Device Example 4 9 1000 1.09 2.58 Device Example 5 10 1000 1.22 2.17 Device Example 6 11 1000 1.28 1.32 Device Example 7 12 1000 1.18 1.45

[0109] It can be seen from the content of Table 1 that the present invention obtains silicon-containing compounds through molecular design. The silicon-containing compounds provided by the present invention can be used as electron transport materials for OLED light-emitting devices, so that the OLED light-emitting devices have higher current efficiency and longer life.

[0110] The applicant declares that the present invention illustrates the silicon-containing compound and its application through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments 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 silicon-containing compound, characterized in that The silicon-containing compound has a structure as shown in the following formula I: Wherein, R1 and R2 are independently selected from any one or a combination of at least two of C1-C12 alkyl, C1-C12 alkoxy, C6-C30 aryl or C3-C30 heteroaryl; L1 is selected from any one of a C6-C30 arylene group or a C3-C30 heteroarylene group; n is an integer selected from 0-1.

2. The silicon-containing compound according to claim 1, characterized in that The C1-C12 alkane group is selected from methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, tert-pentyl, n-hexyl, and cyclohexyl; Preferably, the C1-C12 alkoxy group is selected from methoxy, ethoxy, propoxy, isopropoxy, butoxy, and tert-butoxy.

3. The silicon-containing compound according to claim 1, characterized in that The C6-C30 aryl group is selected from phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, indenylfluorenyl, perylenyl, phenanthrenyl, pyrenyl, fluoranthenyl or triphenylenyl; Preferably, the C6-C30 arylene group is selected from phenylene, biphenylene, terphenylene, naphthylene, anthracene, indenylene, fluorenylene, perylene, phenanthrenylene, pyrenylene, fluoranthenylene or triphenylene.

4. The silicon-containing compound according to any one of claims 1 to 3, characterized in that The heteroatoms in the C3-C30 heteroaryl group are oxygen, sulfur and nitrogen atoms; Preferably, the C3-C30 heteroaryl group is selected from benzofuran, benzothiophene, pyridine, dibenzofuran, pyrimidine, dibenzothiophene, carbazole, diarylideneamine, benzofuranocarbazole, benzofuranothiophene or triazine; Preferably, the C3-C30 heteroarylene group is selected from benzofuranylene, benzothiopheneylene, pyridineylene, dibenzofuranylene, pyrimidineylene, dibenzothiopheneylene, carbazoleylene, diarylamineylene, benzofuranocarbazoleylene, benzofuranothiopheneylene or triazineylene.

5. The silicon-containing compound according to any one of claims 1 to 4, characterized in that The silicon-containing compound includes any one of the following compounds:

6. The silicon-containing compound according to any one of claims 1 to 5, characterized in that The compound represented by formula I is selected from any one of compounds 1 to 12:

7. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises the silicon-containing compound according to any one of claims 1 to 6.

8. The organic electroluminescent device according to claim 7, characterized in that: The organic electroluminescent device comprises a first electrode, a second electrode and an organic layer disposed between the first electrode and the second electrode; the material of the organic layer comprises the silicon-containing compound as claimed in any one of claims 1 to 6.

9. The organic electroluminescent device according to claim 7, characterized in that: The organic layer includes an electron transport layer; the material of the electron transport layer includes the silicon-containing compound as claimed in any one of claims 1 to 6.

10. A display device, characterized in that: The display device comprises the organic electroluminescent device according to any one of claims 7 to 9.

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