Phenazine compound and application thereof

Abstract

The invention provides a phenazine compound and application thereof, and relates to the technical field of organic electroluminescent materials. As a hole transport material, the phenazine compound can effectively improve the photoelectric property and prolong the service life of an OLED (Organic Light Emitting Diode) device.

Description

Technical Field

[0001] The invention belongs to the field of organic photoelectric technology, and specifically relates to a phenazine compound and application thereof. Background Art

[0002] Organic light emitting diode (OLED) device technology can be used to manufacture new display products and new lighting products. It is expected to replace existing liquid crystal displays and fluorescent lighting, and has a wide range of applications. OLED light-emitting devices are like sandwich structures, including electrode material films and organic functional materials sandwiched between different electrode film layers. Various functional materials are superimposed on each other according to their uses to form OLED light-emitting devices. As a current device, when voltage is applied to the electrodes at both ends of the OLED light-emitting device and the electric field acts on the positive and negative charges in the organic layer functional material film layer, the positive and negative charges are further compounded in the light-emitting layer, generating OLED electroluminescence.

[0003] Currently, OLED display technology has been applied in smart phones, tablet computers and other fields, and will further expand to large-size application fields such as TVs. However, compared with the actual product application requirements, the performance of OLED devices such as luminous efficiency and service life needs to be further improved. Current research on improving the performance of OLED light-emitting devices includes: reducing the driving voltage of the device, improving the luminous efficiency of the device, and increasing the service life of the device. In order to continuously improve the performance of OLED devices, it is necessary not only to innovate the structure and manufacturing process of OLED devices, but also to continuously study and innovate OLED optoelectronic functional materials to create higher performance OLED functional materials.

[0004] OLED optoelectronic functional materials used in OLED devices can be divided into two categories based on their uses, namely charge injection transport materials and luminescent materials. Furthermore, charge injection transport materials can be divided into electron injection transport materials, electron blocking materials, hole injection transport materials and hole blocking materials, and luminescent materials can be divided into main luminescent materials and doping materials. In order to make high-performance OLED light-emitting devices, various organic functional materials are required to have good optoelectronic properties. For example, as a charge transport material, it is required to have good carrier mobility, high glass transition temperature, etc., and as the main material of the light-emitting layer, it has good bipolarity and appropriate HOMO / LUMO energy levels.

[0005] The OLED optoelectronic functional material film layer that constitutes the OLED device includes at least two layers of structure. The OLED device structure used in the industry includes multiple layers such as hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc. That is to say, the optoelectronic functional materials used in OLED devices include at least hole injection materials, hole transport materials, light-emitting materials, electron transport materials, etc. The material types and matching forms are rich and diverse. In addition, for the matching of OLED devices with different structures, the optoelectronic functional materials used have strong selectivity, and the performance of the same material in devices with different structures may be completely different.

[0006] Therefore, in view of the current industrial application requirements of OLED devices and the different functional film layers of OLED devices and the photoelectric characteristics of the devices, it is necessary to select more suitable and higher-performance OLED functional materials or material combinations to achieve the comprehensive characteristics of high efficiency, long life and low voltage of the devices. As far as the actual needs of OLEDs are concerned, the current development of OLED materials is far from enough and lags behind the requirements of panel manufacturers. It is particularly important to develop higher-performance organic functional materials. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention aims to provide a phenazine compound and its application. The phenazine compound has excellent performance and is suitable for use as a hole transport material in an organic electroluminescent device.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a phenazine compound, wherein the phenazine compound has a structure as shown in Formula I:

[0010]

[0011] Among them, the structure of A is The structure of B is

[0012] Ar1, Ar2, Ar3, Ar4, Ar5, Ar6 are each independently selected from substituted or unsubstituted C6 to C 30 Aryl, substituted or unsubstituted C3~C 30 Aromatic heterocyclic group;

[0013] Ar3 and Ar4 are connected by a single bond to form a carbazole ring or are not connected;

[0014] Ar5 and Ar6 are connected by a single bond to form a carbazole ring or are not connected;

[0015] In Ar1, Ar2, Ar3, Ar4, Ar5, and Ar6, the substituents substituted are each independently selected from fluorine atoms, cyano groups, C1-C 12 Alkyl, C6~C 30 Aryl or C3~C 30 Aromatic heterocyclic group;

[0016] The hydrogen atoms in formula I may be independently replaced by deuterium atoms, fluorine atoms, cyano groups, C1-C 12 Alkyl, C6~C 30 Aryl or C3~C 30 Aromatic heterocyclic group substitution.

[0017] Preferably, the structures of A and B are the same.

[0018] Preferably, Ar3, Ar4, Ar5, and Ar6 are each independently selected from phenyl, biphenyl, or triphenylene, at least one of Ar3 and Ar4 is triphenylene, at least one of Ar5 and Ar6 is triphenylene, and Ar3 is different from Ar4, and Ar5 is different from Ar6;

[0019] Alternatively, Ar3, Ar4, Ar5, and Ar6 are each independently selected from triphenylene or naphthyl, and Ar3 is different from Ar4, and Ar5 is different from Ar6.

[0020] Preferably, the phenazine compound has a structure as shown in Formula II:

[0021]

[0022] In Formula II, Ar1 and Ar2 are each independently selected from substituted or unsubstituted C6 to C 30 Aryl, substituted or unsubstituted C3~C 30 Aromatic heterocyclic group, wherein the substituents are independently selected from fluorine atoms, cyano groups, C1-C 12 Alkyl, C6~C 30 Aryl or C3~C 30 Aromatic heterocyclic group;

[0023] Ar7 and Ar8 have the same structure, and Ar7 and Ar8 are selected from phenyl, biphenyl or naphthyl.

[0024] Preferably, the C1 to C 12 The alkyl group is selected from methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, tert-pentyl, n-hexyl or cyclohexyl.

[0025] In the present invention, aryl refers to the general term for a monovalent group remaining after removing a hydrogen atom from the aromatic carbon of an aromatic hydrocarbon molecule, which can be a monocyclic aryl or a condensed ring aryl. 30Aryl groups illustratively include, but are not limited to, phenyl, biphenyl, terphenyl, triphenylene, naphthyl, anthracenyl, indenyl, fluorenyl, perylenyl, phenanthrenyl, pyrenyl, fluoranthenyl, or triphenylenyl.

[0026] In the present invention, an aromatic heterocyclic group refers to a group in which one or more aromatic carbon atoms in an aromatic group are replaced by heteroatoms, and may be a monocyclic heteroaryl group or a condensed-ring heteroaryl group. 30 The heteroatoms in the aromatic heterocyclic group include, but are not limited to, oxygen atoms, sulfur atoms, silicon atoms, boron atoms or nitrogen atoms. 30 The aromatic heterocyclic group illustratively includes, but is not limited to, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, a diarylideneamine group, a benzofuranocarbazolyl group, a benzofuranothiophenyl group, or a triazine group.

[0027] 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.

[0028] Preferably, the phenazine compound includes any one of the following compounds 1 to 68:

[0029]

[0030]

[0031]

[0032] The present invention lists some specific structural forms of the phenazine compounds, but the phenazine 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 Ar1, Ar2, Ar3, Ar4, Ar5, and Ar6 meet the above-mentioned limiting conditions should be included.

[0033] In a second aspect, the present invention provides a use of the phenazine compound as a hole transport material in an organic electroluminescent device.

[0034] In a third aspect, the present invention provides an organic electroluminescent device, wherein the organic electroluminescent device comprises the phenazine compound as described in the first aspect.

[0035] 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 phenazine compound as described in the first aspect.

[0036] Preferably, the organic layer includes a hole transport layer; the material of the hole transport layer includes the phenazine compound as described in the first aspect.

[0037] In a fourth aspect, the present invention provides a display device, comprising the organic electroluminescent device as described in the third aspect.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The phenazine compounds of the present invention have good thermal stability and luminescent properties, and can be used to prepare organic electroluminescent devices, especially as hole transport layer materials in organic electroluminescent devices, which can effectively reduce the driving voltage of organic electroluminescent devices and improve the current efficiency of organic electroluminescent devices. DETAILED DESCRIPTION

[0040] For the convenience of understanding the present invention, the present invention lists the following embodiments. 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.

[0041] Synthesis Example 1

[0042] This embodiment provides a method for synthesizing compound 1. The synthetic route of compound 1 is as follows:

[0043]

[0044] 49 g of dibromophenazine-1, 40.56 g of diphenylamine, 55.2 g of sodium tert-butyl alcohol, 4.5 g of tri(dibenzylideneacetone)dipalladium, 5.6 g of tri-tert-butylphosphine tetrafluoroborate and 500 mL of toluene were mixed and heated under argon protection for 12 h of reflux reaction. After the reaction was completed, 500 ml of water was added, the organic phase was separated, the separated organic phase was dried and the solvent was removed by distillation, and 48.7 g of compound 1 was separated by silica gel chromatography (the solvent used in silica gel chromatography was a mixture of toluene and n-hexane, wherein the volume ratio of toluene to n-hexane was 1:1).

[0045] The mass spectrometry test of compound 1 measured the charge-to-mass ratio m / z: 668.3.

[0046] Synthesis Example 2

[0047] This embodiment provides a method for synthesizing compound 2. The synthetic route of compound 2 is as follows:

[0048]

[0049] Referring to the synthesis method of Synthesis Example 1, carbazole was used to replace the diphenylamine in Synthesis Example 1, and other conditions remained unchanged to obtain Compound 2.

[0050] The mass spectrometry test of compound 2 showed that the charge-to-mass ratio m / z was 664.3.

[0051] Synthesis Example 3

[0052] This embodiment provides a method for synthesizing compound 3. The synthetic route of compound 3 is as follows:

[0053]

[0054] Referring to the synthesis method of Synthesis Example 1, dibromophenazine-2 was used to replace dibromophenazine-1 in Synthesis Example 1, and other conditions remained unchanged to obtain Compound 3.

[0055] The mass spectrometry test of compound 3 showed that the charge-to-mass ratio m / z was 668.3.

[0056] Synthesis Example 4

[0057] This embodiment provides a method for synthesizing compound 4. The synthetic route of compound 4 is as follows:

[0058]

[0059] Referring to the synthesis method of Synthesis Example 3, carbazole was used to replace the diphenylamine in Synthesis Example 3, and other conditions remained unchanged to obtain Compound 4.

[0060] The mass spectrometry test of compound 4 showed that the charge-to-mass ratio m / z was 664.3.

[0061] Synthesis Example 5

[0062] This example provides a method for synthesizing compound 65, and the synthetic route is as follows:

[0063]

[0064] Referring to the synthesis method of Synthesis Example 4, amine-1 was used to replace the carbazole in Synthesis Example 4, and other conditions remained unchanged to obtain Compound 65.

[0065] The mass spectrometry test of compound 65 showed that the charge-to-mass ratio m / z was 968.4.

[0066] Synthesis Example 6

[0067] This example provides a method for synthesizing compound 66, and the synthetic route is as follows:

[0068]

[0069] Referring to the synthesis method of Synthesis Example 4, amine-2 was used to replace the carbazole in Synthesis Example 4, and other conditions remained unchanged to obtain Compound 66.

[0070] The mass spectrometry test of compound 66 showed that the charge-to-mass ratio m / z was 1120.5.

[0071] Synthesis Example 7

[0072] This example provides a method for synthesizing compound 67, and the synthetic route is as follows:

[0073]

[0074] Referring to the synthesis method of Synthesis Example 4, amine-3 was used to replace the carbazole in Synthesis Example 4, and other conditions remained unchanged to obtain Compound 67.

[0075] The mass spectrometry test of compound 67 showed that the charge-to-mass ratio m / z was 1068.4.

[0076] Synthesis Example 8

[0077] This example provides a method for synthesizing compound 68, and the synthetic route is as follows:

[0078]

[0079] Referring to the synthesis method of Synthesis Example 4, amine-4 was used to replace the carbazole in Synthesis Example 4, and other conditions remained unchanged to obtain Compound 68.

[0080] Compound 68 was subjected to mass spectrometry and the charge-to-mass ratio m / z was measured to be 1068.4.

[0081] Other compounds for which specific synthesis steps are not listed can be prepared by common knowledge in the art in combination with the above synthesis examples.

[0082] The specific structures of some compounds used in the following device examples and device comparative examples are shown below:

[0083]

[0084] In the following device examples, the phenazine compounds provided by the present invention are selected as hole transport materials in organic electroluminescent devices, and in the device comparative examples, the above H-1 is selected as the hole transport material in organic electroluminescent devices.

[0085] Device Example 1

[0086] The device embodiment provides an organic electroluminescent device, using the compound 1 provided in Synthesis Example 1 of the present invention as a hole transport material.

[0087] The structure of the organic electroluminescent device is:

[0088] ITO (150 nm) / HAT-CN (10 nm) / Compound 1 (60 nm) / EB-1 (10 nm) / BH:BD 5% (35 nm) / TPBI&LiQ (35 nm) / LiF (1 nm) / Al (100 nm).

[0089] The preparation method of the organic electroluminescent device is as follows:

[0090] Transparent glass was used as the substrate layer, on which ITO with a thickness of 150 nm was coated as the anode layer, which was sequentially washed with alkali and pure water, then dried, and then washed with ultraviolet-ozone to remove organic residues on the surface of the transparent ITO.

[0091] On the washed ITO anode layer, HAT-CN with a thickness of 10 nm was evaporated using a vacuum evaporation device as a hole injection layer.

[0092] Next, compound 1 was evaporated to a thickness of 60 nm as a hole transport layer, and then EB-1 was evaporated to a thickness of 10 nm as an electron blocking layer.

[0093] Subsequently, vacuum evaporation was performed on the electron blocking layer to obtain a light-emitting layer with a thickness of 35 nm. The components of the light-emitting layer included a main material BH and a doping material BD, and the mass ratio of BH to BD was 95:5.

[0094] Then, an electron transport layer with a thickness of 35 nm was vacuum evaporated on the light-emitting layer. The components of the electron transport layer included TPBI and Liq, and the mass ratio of TPBI to Liq was 1:1.

[0095] Next, lithium fluoride (LiF) was vacuum-deposited to a thickness of 1 nm on the electron transport layer as an electron injection layer. Finally, aluminum (Al) was vacuum-deposited to a thickness of 100 nm on the electron injection layer as a cathode layer.

[0096] Device Examples 2 to 10

[0097] Device Examples 2 to 10 respectively provide an organic electroluminescent device, which differs from Device Example 1 only in that the hole transport material is different (see Table 1 below for details), and other conditions are the same as those of Device Example 1.

[0098] Device Comparative Example 1

[0099] Device Comparative Example 1 provides an organic electroluminescent device, which is different from Device Example 1 only in that the hole transport material is different (see Table 1 below for details), and other conditions are the same as those of Device Example 1.

[0100] Performance Testing

[0101] Test the driving voltage, current efficiency and life LT95 of the OLED devices provided above; LT95 refers to the time required for the brightness to drop to 95% 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 LT95 data are all based on a brightness of 1000cd / m 2 The relative value of the material H-1 is shown in Table 1 below:

[0102] Table 1

[0103]

[0104] As can be seen from the contents of Table 1, the phenazine compounds provided by the present invention can be used as hole transport materials for OLED light-emitting devices, so that the OLED light-emitting devices have lower driving voltage, higher current efficiency and longer life. In particular, it can be seen from Examples 11 to 14 that when the nitrogen atoms in the two nitrogen-containing groups connected to the phenazine core of the compound are connected to triphenylene and phenyl at the same time, the OLED light-emitting device can have an outstanding service life, such as compound 65; when the nitrogen atoms in the two nitrogen-containing groups connected to the phenazine core of the compound are connected to triphenylene and biphenyl at the same time, the OLED light-emitting device can have an outstanding service life, such as compound 66; when the nitrogen atoms in the two nitrogen-containing groups connected to the phenazine core of the compound are connected to triphenylene and naphthyl at the same time, the OLED light-emitting device can have an outstanding current efficiency and significantly reduce the driving voltage, such as compounds 67 to 68.

[0105] The applicant declares that 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 phenazine compound, characterized in that: The phenazine compound has a structure as shown in Formula I: Among them, the structure of A is The structure of B is Ar1, Ar2, Ar3, Ar4, Ar5, Ar6 are each independently selected from substituted or unsubstituted C6 to C 30 Aryl, substituted or unsubstituted C3~C 30 Aromatic heterocyclic group; Ar3 and Ar4 are connected by a single bond to form a carbazole ring or are not connected; Ar5 and Ar6 are connected by a single bond to form a carbazole ring or are not connected; In Ar1, Ar2, Ar3, Ar4, Ar5, and Ar6, the substituents substituted are each independently selected from fluorine atoms, cyano groups, C1-C 12 Alkyl, C6~C 30 Aryl or C3~C 30 Aromatic heterocyclic group; The hydrogen atoms in formula I may be independently replaced by deuterium atoms, fluorine atoms, cyano groups, C1-C 12 Alkyl, C6~C 30 Aryl or C3~C 30 Aromatic heterocyclic group substitution.

2. The phenazine compound according to claim 1, characterized in that The structures of A and B are the same.

3. The phenazine compound according to claim 1, characterized in that Ar3, Ar4, Ar5, and Ar6 are each independently selected from phenyl, biphenyl, or triphenylene, at least one of Ar3 and Ar4 is triphenylene, at least one of Ar5 and Ar6 is triphenylene, and Ar3 is different from Ar4, and Ar5 is different from Ar6; Alternatively, Ar3, Ar4, Ar5, and Ar6 are each independently selected from triphenylene or naphthyl, and Ar3 is different from Ar4, and Ar5 is different from Ar6.

4. The phenazine compound according to claim 1, characterized in that C1~C 12 The alkyl group is selected from methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, tert-pentyl, n-hexyl or cyclohexyl; C6~C 30 Aryl is selected from phenyl, biphenyl, terphenyl, triphenylene, naphthyl, anthracenyl, indenyl, fluorenyl, perylenyl, phenanthrenyl, pyrenyl, fluoranthenyl or triphenylenyl.

5. The phenazine compound according to claim 1, characterized in that C3~C 30 The hetero atom in the aromatic heterocyclic group is an oxygen atom, a sulfur atom, a silicon atom, a boron atom or a nitrogen atom.

6. The phenazine compound according to claim 1, characterized in that C3~C 30 The aromatic heterocyclic group is selected from benzofuranyl, benzothiophenyl, dibenzofuranyl, dibenzothiophenyl, carbazolyl, diarylideneamine, benzofuranocarbazolyl, benzofuranothiophenyl or triazine.

7. The phenazine compound according to claim 1, characterized in that: The phenazine compound includes any one of the following compounds 1 to 68:

8. Use of the phenazine compound according to any one of claims 1 to 7 as a hole transport material in an organic electroluminescent device.

9. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises the phenazine compound according to any one of claims 1 to 7.

10. The organic electroluminescent device according to claim 9, 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 organic layer comprises a hole transport layer; and the material of the hole transport layer comprises the phenazine compound.

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