Nitrogen and oxygen-containing heterocyclic compound, organic electroluminescent device and display device

Abstract

The invention provides a heterocyclic compound containing nitrogen and oxygen, an organic electroluminescent device and a display device, and relates to the technical field of organic photoelectricity. The nitrogen and oxygen-containing heterocyclic compound can increase the electron transmission capability of a device, reduce the electron injection transmission barrier and reduce the driving voltage so as to improve the luminous efficiency of the device, has good luminous performance, can be used for preparing the organic electroluminescent device, especially can be used as an electron transmission layer material in the organic electroluminescent device, and has wide application prospects. The driving voltage of the organic light-emitting device can be effectively reduced, and the current efficiency of the organic light-emitting device is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic optoelectronics, and particularly relates to a nitrogen- and oxygen-containing heterocyclic compound, an organic electroluminescent device, and a display device. Background Art

[0002] An organic light emitting diode (OLED) is a display component that utilizes the phenomenon of self-luminescence. It has a large viewing angle. Compared with liquid crystal display components, OLED components are thinner, lighter, have a faster response speed, and can achieve flexible display. Therefore, its application as a full-color display component or a lighting device is highly anticipated.

[0003] As OLED products gradually enter the market, people have higher and higher requirements for the performance of such products. The selection of materials for the hole layer, light emitting layer, and other organic functional layers has a great influence on the current efficiency, driving voltage, and lifespan of the device. Currently, the exploration of functional layer materials with higher performance is still ongoing. Therefore, in order to meet people's higher requirements for OLED devices, there is an urgent need in this field to develop more types of OLED materials with higher performance. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a nitrogen- and oxygen-containing heterocyclic compound, an organic electroluminescent device, and a display device. The nitrogen- and oxygen-containing heterocyclic compound can be used as an electron transport material for OLED devices, and the obtained organic electroluminescent device has a lower driving voltage, a higher current efficiency, and a longer lifespan.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] In the first aspect, the present invention provides a nitrogen- and oxygen-containing heterocyclic compound having a structure shown in Formula I:

[0007]

[0008] In Formula I, R 1 and R 2 are each independently selected from a substituted or unsubstituted C 6 - C 30 aryl group or a substituted or unsubstituted C 3 - C 30 heteroaryl group;

[0009] Ar 1 is selected from a single bond, a substituted or unsubstituted C 6 - C 30 arylene group or a substituted or unsubstituted C 3 - C 30 heteroarylene group;

[0010] A 1 、A 2 、A 3 are each independently selected from CH or N, and at least one of A 1 、A 2 、A 3 is N;

[0011] The substituents of the substitution are selected from C 6 ~C 30 aryl or C 3 ~C 30 heteroaryl.

[0012] Preferably, A 1 、A 2 、A 3 are all N, or any two of A 1 、A 2 、A 3 are N, or any one of A 1 、A 2 、A 3 is N.

[0013] More preferably, A 1 、A 2 、A 3 are all N; or A 1 、A 3 is N, and A 2 is CH.

[0014] Preferably, the C 6 ~C 30 aryl is selected from phenyl, biphenyl, terphenyl, naphthyl, anthryl, indenyl, fluorenyl, perylenyl, phenanthryl, pyrenyl, fluoranthenyl, spirobifluorenyl or benzo[ghi]perylenyl.

[0015] Preferably, the C 3 ~C 30 heteroaryl is selected from benzofuranyl, benzothiophenyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl, diarylamino, benzofurocarbazolyl, benzofurothiophenyl or triazinyl.

[0016] Preferably, the C 6 ~C 30 arylene is selected from phenylene, biphenylene, terphenylenylene, naphthylene, anthrylene, indenylene, fluorenylene, perylenylene, phenanthrylene, pyrenylene, fluoranthenylene, spirobifluorenylene or benzo[ghi]perylenylene.

[0017] Preferably, the C 3 ~C 30The heteroaryl group is selected from benzofuranyl, benzothienyl, dibenzofuranyl, dibenzothienyl, carbazolyl, diarylamino, benzofurocarbazolyl, benzofurothienyl or triazinyl.

[0018] Preferably, the nitrogen- and oxygen-containing heterocyclic compound is selected from any one of the following compounds:

[0019]

[0020]

[0021]

[0022]

[0023]

[0024] Preferably, the nitrogen- and oxygen-containing heterocyclic compound is selected from any one of the following Compounds 1-16:

[0025]

[0026] In a second aspect, the present invention provides an organic electroluminescent device, and the organic electroluminescent device includes the nitrogen- and oxygen-containing heterocyclic compound described above.

[0027] Preferably, the organic electroluminescent device includes 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 includes the nitrogen- and oxygen-containing heterocyclic compound described above.

[0028] Preferably, the organic layer includes an electron transport layer; the material of the electron transport layer includes the nitrogen- and oxygen-containing heterocyclic compound described above.

[0029] In a third aspect, the present invention provides a display device, and the display device includes the organic electroluminescent device described above.

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

[0031] The nitrogen- and oxygen-containing heterocyclic compound provided by the present invention can increase the electron transport ability of the device, reduce the electron injection and transport barrier, reduce the driving voltage, and further improve the light emission efficiency of the device through a specific structural design. It has good light emission performance and can be used to prepare an organic electroluminescent device. Especially as the material of the electron transport layer in the organic electroluminescent device, it can effectively reduce the driving voltage of the organic electroluminescent device and improve the current efficiency of the organic electroluminescent device. Specific Embodiments

[0032] To facilitate the understanding of the present invention, the following examples are enumerated. Those skilled in the art should understand that the said examples are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0033] Synthesis Example 1

[0034] This example provides a method for synthesizing Compound 1, and the synthesis route of the said Compound 1 is as follows:

[0035]

[0036] Synthesis of Intermediate I

[0037] Under nitrogen protection, 20.0 mmol of 2-bromo-1-iododibenz[b,d]furan, 24.0 mmol of 6-chloro-1-methoxy-9H-carbazole, 30.0 mmol of potassium carbonate, 4.0 mmol of copper(I) iodide, 3.0 mmol of 1,10-phenanthroline, 3.0 mmol of 18-crown-6, and 200 mL of dimethyl sulfoxide were added to a reaction flask. The temperature was raised to 150 °C, and the mixture was stirred for reaction for 24 h. Then it was cooled to room temperature, 400 mL of water was added, and a large amount of solid precipitated. Stir for 30 min, filter by suction. The filter cake was washed twice with water and recrystallized with a mixed solvent of toluene and ethanol to obtain Intermediate I.

[0038] Intermediate I was detected by mass spectrometry, and the m / z was 475.00.

[0039] Synthesis of Intermediate II

[0040] Under nitrogen protection, 20.0 mmol of Intermediate I was dissolved in 80 mL of dry dichloromethane, and the temperature was cooled to 0 °C. 44.0 mmol of boron tribromide was added dropwise, and the mixture was stirred for reaction for 2 h. Then 50 mL of 1 M dilute hydrochloric acid aqueous solution was added, and liquid separation was carried out. The organic phase was collected. After the aqueous phase was extracted with dichloromethane, the organic phases were combined and dried, filtered. The filtrate was concentrated under reduced pressure until no liquid remained, and was separated and purified by silica gel column to obtain Intermediate II.

[0041] Intermediate II was detected by mass spectrometry, and the m / z was 460.98.

[0042] Synthesis of Intermediate III

[0043] Under nitrogen protection, 20.0 mmol of Intermediate III was dissolved in 60 mL of DMF, and then 50.0 mmol of anhydrous potassium carbonate was added. The temperature was raised to 120 °C and stirred for reaction for 15 h. After the reaction ended, it was cooled to room temperature. The reaction solution was poured into 150 mL of water, stirred for 30 min, filtered. The filter cake was washed with water and then with ethanol in sequence, and was separated and purified by silica gel column to obtain Intermediate III.

[0044] Intermediate III was detected by mass spectrometry, and the m / z was 381.06.

[0045] Synthesis of Intermediate Ⅳ

[0046] Under nitrogen protection, add 20.0 mmol of Intermediate Ⅳ, 30 mmol of bis(pinacolato)diboron, 0.4 mmol of bis(triphenylphosphine)palladium dichloride, 60 mmol of potassium acetate, and 200 ml of toluene into the reaction flask. Heat the mixture to reflux and stir for 6 h. After the reaction is completed, cool it to room temperature. Add 400 ml of water to the reaction solution, stir for 30 min, separate the layers, and wash the organic layer twice with 300 ml of water. Concentrate the organic phase to 100 ml, add 200 ml of ethanol, stir for 30 min, filter by suction. Recrystallize the filter cake with a mixed solvent of toluene and ethanol to obtain Intermediate Ⅳ.

[0047] Perform mass spectrometry detection on Intermediate Ⅳ, and the m / z is 473.18.

[0048] Synthesis of Compound 1

[0049] Under nitrogen protection, add 20.0 mmol of 2-chloro-4,6-diphenyl-1,3,5-triazine, 22.0 mmol of Intermediate IV, 0.4 mmol of tetrakis(triphenylphosphine)palladium, 30 mmol of potassium carbonate, 300 ml of toluene, 100 ml of ethanol, and 100 ml of water into the reaction flask. Heat the mixture to reflux and stir for 12 h. After the reaction is completed, cool it to room temperature. Add 400 ml of ethanol to the reaction solution, stir for 30 min, filter by suction. Wash the filter cake twice with 300 ml of water, filter by suction again. Recrystallize the filter cake with a mixed solvent of toluene and ethanol to obtain Compound 1.

[0050] Perform mass spectrometry detection on Compound 1, and the m / z is 578.17.

[0051] Refer to the above synthesis method to prepare the compounds shown in Table 1 below. Different from Compound 1, only replace 2-chloro-4,6-diphenyl-1,3,5-triazine with other raw materials (see Table 1), and keep other conditions unchanged:

[0052] Table 1

[0053]

[0054]

[0055]

[0056]

[0057]

[0058] For other compounds whose specific synthesis steps are not listed, they can be prepared by combining the above examples with the common general knowledge in the art.

[0059] The specific structures of some of the compounds used in the following device examples and device comparative examples are shown below:

[0060]

[0061] In the following device examples, the nitrogen- and oxygen-containing heterocyclic compound provided by the present invention is selected as the electron transport material in the organic electroluminescent device, and in the device comparative example, the above D-1 is selected as the electron transport material in the organic electroluminescent device.

[0062] Device Example 1

[0063] Device Example 1 provides an organic electroluminescent device, using Compound 1 provided by Synthesis Example 1 of the present invention as the electron transport material; and in this example, the light-emitting layer is prepared by a solution method.

[0064] The structure of the organic electroluminescent device is:

[0065] ITO / NPB(40nm) / GH-1:Ir(piq)3 33% / Compound 1(30nm) / LiF(0.5nm) / Al(150nm).

[0066] The preparation method of the above organic electroluminescent device is as follows:

[0067] The glass substrate coated with the ITO transparent conductive layer (as the anode) is ultrasonically treated in a cleaning agent, then rinsed in deionized water, then ultrasonically degreased in a mixed solvent of acetone and ethanol, and then baked in a clean environment until completely dehydrated, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam on the surface to improve the surface properties and enhance the bonding ability with the hole injection layer; the above glass substrate is placed in a vacuum chamber, evacuated to 1×10 -6 ~1×10 -5 Pa, and NPB is vacuum-evaporated on the anode as the hole transport layer, with an evaporation rate of 0.1 nm / s and an evaporated film thickness of 40 nm;

[0068] The glass substrate on which the hole transport layer has been evaporated is transferred to a glove box filled with nitrogen, and the light-emitting layer solution is spin-coated on the hole transport layer. The light-emitting layer solution is composed of a light-emitting layer material and a solvent. The light-emitting layer material is composed of GH-1 and Ir(piq)3 equivalent to 3% of the mass of GH-1, and the solvent is composed of anisole, chlorobenzene, and diphenyl ether mixed in a volume ratio of 3:1:10; the spin-coating speed is 1000 revolutions / min, the time is 60 seconds, and then the above glass substrate is heated at 90°C for 16 hours, and the solvent is removed under vacuum. By adjusting the concentrations of GH-1 and Ir(piq)3 in the solvent, the thickness of the obtained light-emitting layer is 34 - 36 nm, and the specific thicknesses are listed in Table 2 (the unit of the light-emitting layer film thickness is nm).

[0069] Transfer the glass substrate spin-coated with the light-emitting layer in the previous step to a vacuum chamber, and vacuum deposit Compound 1 on top of the light-emitting layer as the electron transport layer of the device at a deposition rate of 0.1 nm / s and a deposition thickness of 30 nm; vacuum deposit 0.5 nm of LiF and 150 nm of Al on the electron transport layer as the electron injection layer and the cathode. Measure the brightness, driving voltage, and current efficiency of the fabricated organic light-emitting device.

[0070] Device Examples 2 - 16

[0071] Device Examples 2 - 16 respectively provide an organic light-emitting device, which is different from Device Example 1 only in that the electron transport material is different (see Table 2 below), and other conditions are the same as those in Device Example 1.

[0072] Device Comparative Example 1

[0073] Device Comparative Example 1 provides an organic light-emitting device, which is different from Device Example 1 only in that the electron transport material is different (see Table 2 below), and other conditions are the same as those in Device Example 1.

[0074] Test the driving voltage, current efficiency, and lifetime LT90 of the OLED devices provided above; among them, LT90 refers to the time required for the current density to remain unchanged while maintaining the initial brightness of 1000 nit and the brightness to drop to 90% of the original brightness. The test items include the brightness, driving voltage, and current efficiency of the organic light-emitting device. The driving voltage, current efficiency, and LT90 data are all relative values at a brightness of 1000 cd / m 2 (based on the test data of Device Comparative Example 1). The performance test results of the organic light-emitting device are shown in Table 2 below:

[0075] Table 2

[0076]

[0077]

[0078] It can be seen from the content of Table 2 that through the design of the structure of the nitrogen- and oxygen-containing heterocyclic compound, the present invention increases the electron transport ability of the device, reduces the electron injection and transport barrier, reduces the driving voltage, and thus improves the light-emitting efficiency of the device. As the electron transport material of the OLED light-emitting device, the OLED light-emitting device has a lower driving voltage, a higher current efficiency, and a longer lifetime.

[0079] The present invention illustrates the detailed process flow of the present invention through the above embodiments. However, the present invention is not limited to the above detailed process flow, that is, it does not mean that the present invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent substitution of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc. all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A nitrogen-oxygen-containing heterocyclic compound, characterized in that: The nitrogen-oxygen-containing heterocyclic compound has a structure as shown in Formula I: In Formula I, R1 and R2 are each independently selected from substituted or unsubstituted C6 to C 30 Aryl or substituted or unsubstituted C3~C 30 heteroaryl; Ar1 is selected from a single bond, a substituted or unsubstituted C6~C 30 Arylene or substituted or unsubstituted C3~C 30 heteroarylene; A1, A2, A3 are each independently selected from CH or N, and at least one of A1, A2, A3 is N; the substituted substituent is selected from C6 to C 30 Aryl or C3~C 30 Heteroaryl.

2. The nitrogen-oxygen-containing heterocyclic compound according to claim 1, characterized in that C6~C 30 Aryl is selected from phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, indenyl, fluorenyl, perylenyl, phenanthrenyl, pyrenyl, fluoranthenyl, spirobifluorenyl or triphenylenyl.

3. The nitrogen-oxygen-containing heterocyclic compound according to claim 1, characterized in that C3~C 30 The heteroaryl group is selected from benzofuranyl, benzothiophenyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl, diarylideneamine, benzofuranocarbazolyl, benzofuranothiophenyl or triazine.

4. The nitrogen-oxygen-containing heterocyclic compound according to claim 1, characterized in that C6~C 30 The arylene group is selected from phenylene, biphenylene, terphenylene, naphthylene, anthracene, indenylene, fluorenylene, perylene, phenanthrenylene, pyrenylene, fluoranthenylene, spirobifluorenylene or triphenylene.

5. The nitrogen-oxygen-containing heterocyclic compound according to claim 1, characterized in that C3~C 30 The heteroarylene group is selected from benzofuranylene, benzothiophenylene, dibenzofuranylene, dibenzothiophenylene, carbazolylene, diaryleneamino group, benzofuranocarbazolylene, benzofuranothiophenylene or triazinylene.

6. The nitrogen-oxygen-containing heterocyclic compound according to claim 1, characterized in that The nitrogen-oxygen-containing heterocyclic compound is selected from any one of the following compounds:

7. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises the nitrogen-oxygen-containing heterocyclic 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 arranged between the first electrode and the second electrode; the material of the organic layer comprises the heterocyclic compound containing nitrogen and oxygen.

9. The organic electroluminescent device according to claim 8, characterized in that: The organic layer includes an electron transport layer; the material of the electron transport layer includes the nitrogen-oxygen-containing heterocyclic compound.

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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