A compound containing tricarbazole structure and an organic electroluminescent device

Abstract

The present invention provides a compound containing a tricarbazole structure and an organic electroluminescent device, and relates to the technical field of organic electroluminescent. The structural formula of the compound containing a tricarbazole structure is shown in Formula 1: #imgabs0#. The introduction of deuterium in the compound improves the chemical stability and thermal stability of the material, thereby greatly improving the stability and life of the device, and the deuteration at a special position improves the performance while being economical. At the same time, the deuterated GH material and the deuterated GD material have better phase solubility, are more conducive to energy transfer, and thus improve the preparation yield, stability, efficiency and life of the device.

Description

Technical Field

[0001] The present invention relates to the technical field of organic electroluminescence, and in particular to a compound containing a tricarbazole structure and an organic electroluminescent device. Background Art

[0002] Generally speaking, an organic electronic device that uses electrical energy to make an organic material emit light usually has a structure including an anode and a cathode and an organic material layer therebetween. Here, the organic layer is usually formed of a multilayer structure composed of different materials to improve the efficiency and stability of the organic electronic device, such as a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer.

[0003] Research on improving the performance of organic electroluminescent 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 organic electroluminescent devices, it is necessary not only to continuously research and innovate organic electrophotoelectric functional materials and create higher performance organic electrophotoelectric functional materials, but also to innovate the structure and manufacturing process of organic electroluminescent devices, and continuously require the development of new materials for organic light-emitting devices as described above.

[0004] 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. For TTF characteristic OLED light-emitting devices, in order to pursue a stable and efficient TTF light-emitting effect, there are certain requirements for the physical properties of the host and guest materials. At the same time, the host and guest materials are required to have the best combination and matching form, and good carrier injection and good carrier balance of the light-emitting layer are also required. The compounds and organic electroluminescent devices in the present invention can improve the green light emitting efficiency and life, and promote the localization of OLED materials. Summary of the invention

[0005] The purpose of the present invention is to provide a compound containing a tricarbazole structure and an organic electroluminescent device based on the prior art.

[0006] The purpose of the present invention can be achieved by the following measures:

[0007] A compound containing a tricarbazole structure, the structural formula of which is shown in Formula 1 below:

[0008]

[0009] A 1-A5 is independently selected from hydrogen, deuterium, deuterated or undeuterated groups: one or more of C1-C10 alkyl, C3-C10 cycloalkyl, C6-C18 aryl or C5-C24 heteroaryl;

[0010] L is a single bond, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, and its substituent is selected from one or more of deuterium, fluorine, cyano, C6-C18 aryl, C6-C20 deuterated aryl, and C5-C20 heteroaryl;

[0011] G is carbazole, and its substituent is selected from one or more of deuterium, fluorine, cyano, C6-C18 aryl, C6-C18 deuterated aryl, and C5-C24 heteroaryl;

[0012] R1 and R2 are each independently deuterium, a substituted or unsubstituted C6-18 aromatic group, or a substituted or unsubstituted C5-24 heteroaryl group, wherein the substituent is selected from one or more of deuterium, a C6-18 aromatic group, or a C5-C24 heteroaryl group;

[0013] n is an integer from 0 to 3;

[0014] m is an integer from 0 to 7.

[0015] In a preferred embodiment, the structural formula is shown in Formula 2 below:

[0016]

[0017] A 1- A5 is independently selected from hydrogen, deuterium, deuterated or undeuterated groups: one or more of C6-C12 aryl or C5-C18 heteroaryl;

[0018] R1 and R2 are each independently deuterium, a substituted or unsubstituted C6-C12 aromatic group, or a substituted or unsubstituted C5-C18 heteroaryl group, wherein the substituent is selected from one or more of deuterium, a C6-C12 aromatic group, or a C5-C18 heteroaryl group;

[0019] G is carbazole, and its substituent is selected from one or more of deuterium, C6-C12 aryl, C6-C12 deuterated aryl, and C5-C18 heteroaryl;

[0020] n is an integer from 0 to 3;

[0021] m is an integer from 0 to 7;

[0022] p is 0 or 1.

[0023] Preferably, A 1-A5 is independently selected from hydrogen, deuterium, deuterated or undeuterated groups: one or more of phenyl, biphenyl, terphenyl, triphenylene;

[0024] R1 and R2 are each independently deuterium, a substituted or unsubstituted C6-C12 aromatic group, and the substituent is selected from deuterium, a deuterated or undeuterated phenyl group or a biphenyl group;

[0025] G is carbazole, and its substituent is selected from one or more of deuterium, fluorine, cyano, phenyl, deuterated phenyl, pyridyl, naphthyl, biphenyl, and deuterated biphenyl.

[0026] Further preferably, A 1- A5 is independently selected from hydrogen, deuterium, deuterated or undeuterated groups: one or more of phenyl and biphenyl;

[0027] R1 and R2 are each independently deuterium, substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, wherein the substituent is selected from deuterium, deuterated or undeuterated phenyl or biphenyl;

[0028] G is carbazole, and its substituent is selected from one or more of deuterium, fluorine, cyano, phenyl, and deuterated phenyl.

[0029] More preferably, A 1- A5 is independently selected from hydrogen, deuterium, deuterated or undeuterated phenyl, deuterated or undeuterated biphenyl;

[0030] R1-R2 are each independently deuterium, deuterated or undeuterated phenyl, deuterated or undeuterated biphenyl;

[0031] G is carbazole, and its substituent is selected from one or more of deuterium, phenyl, and deuterated phenyl;

[0032] n is an integer from 0 to 3;

[0033] m is an integer from 0 to 7;

[0034] p is 0 or 1.

[0035] In a preferred embodiment, the compound of the present invention is any one of the following compounds:

[0036] .

[0037] An organic electroluminescent device comprises a first electrode, a second electrode and an organic layer formed between the first electrode and the second electrode; wherein the organic layer contains the compound of the present invention.

[0038] Furthermore, the organic layer comprises a hole injection layer, a first hole transport layer, a second hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer; wherein the light-emitting layer contains the compound of the present invention.

[0039] Furthermore, the light-emitting layer contains a light-emitting host material, which is a mixture of the compound of the present invention and any one or more of compounds G1-G51. Compounds G1-G51 are as follows: .

[0040] An electronic display device containing the organic electroluminescent device of the present invention.

[0041] An OLED lighting device comprising the organic electroluminescent device of the present invention.

[0042] The room temperature described in the present invention is 25±5°C.

[0043] Beneficial effects of the present invention:

[0044] The technical solution of the present invention has the following advantages:

[0045] The introduction of deuterium improves the chemical and thermal stability of this type of material, thereby greatly improving the stability and life of the device, and deuterium substitution at special positions improves performance while being economical. At the same time, the deuterated GH material and the deuterated GD material have better phase solubility, which is more conducive to energy transfer, thereby improving the preparation yield, stability, efficiency and life of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of the structure of an organic electroluminescent device provided by the present invention;

[0047] The numbers in the figure represent: 1-anode, 2-hole injection layer, 3-first hole transport layer, 4-second hole transport layer, 5-light-emitting layer, 6-hole blocking layer, 7-electron transport layer, 8-electron injection layer, 9-cathode;

[0048] Figure 2 is the HPLC chart of compound 6 prepared in Example 1 of the present invention;

[0049] Figure 3 is the DSC spectrum of compound 6 prepared in Example 1 of the present invention, Figure 3 It can be seen that the Tg value of compound 6 is 150.56°C;

[0050] Figure 4 is the TGA spectrum of compound 6 prepared in Example 1 of the present invention, Figure 4 It can be seen that the thermal weight loss temperature Td value is 499.50℃;

[0051] Figure 5 This is the H NMR spectrum of compound 6 prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0052] The following further illustrates and describes embodiments of various aspects. It should be understood that the description herein is not intended to limit the claims to the specific aspects described. On the contrary, it is intended to cover substitutions, modifications and equivalents that may be included in the spirit and scope of the present disclosure defined by the appended claims.

[0053] As used herein, in "substituted" or "unsubstituted", the term "substituted" means that at least one hydrogen in the group is re-coordinated with deuterium, a hydrocarbon group, a hydrocarbon derivative group, a halogen, or a cyano group (-CN). The term "unsubstituted" means that at least one hydrogen in the group is not re-coordinated with deuterium, a hydrocarbon group, a hydrocarbon derivative group, a halogen, or a cyano group (-CN). Examples of hydrocarbon groups or hydrocarbon derivative groups may include C1 to C30 alkyl, C2 to C30 alkenyl, C2 to C30 alkynyl, C6 to C30 aryl, C5 to C30 heteroaryl, C1 to C30 alkylamino, C6 to C30 arylamino, C6 to C30 heteroarylamino, C6 to C30 arylheteroarylamino, etc., but are not limited thereto.

[0054] Herein, “n is an integer of 0-3” means that n can be 0, 1, 2, or 3 independently.

[0055] Herein, “m is an integer of 0-7” means that m can be 0, 1, 2, 3, 4, 5, 6, or 7 independently.

[0056] Deuterium in the present invention refers to a stable isotope of hydrogen, also known as heavy hydrogen, and its element symbol is D.

[0057] The aromatic group in the present invention refers to an all-carbon monocyclic or condensed polycyclic group of 6 to 30 carbon atoms, having a completely conjugated π electron system. Non-limiting examples of aromatic groups include phenyl, naphthyl, anthracenyl, biphenyl, o-terphenyl, m-terphenyl, p-terphenyl, triphenyl[1,12-bcd]furanyl, phenanthrenyl, and the like.

[0058] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0059] Embodiment 1:

[0060]

[0061] The synthesis method of compound 6 is as follows:

[0062]

[0063]

[0064]

[0065] .

[0066] Under nitrogen protection, 3,6-dibromodeuterated carbazole 1-a (70 g, 0.21 mol, 1 eq) and ultra-dry THF 500 ml were added to the reaction flask, the temperature was lowered to -70 ° C, and n-butyl lithium (176 ml, 0.441 mol, 3.1 eq) was added dropwise. After the addition was completed, the reaction solution was reacted at -70 ° C for 1 h. Saturated aqueous ammonium chloride solution was added to the reaction solution, stirred for 30 min, and then separated. The organic phase was concentrated to dryness to obtain about 32 g of product 1-b with a yield of 60%.

[0067] Under nitrogen protection, the intermediate 1-c (45.7 g, 0.139 mol, 1 eq) and 500 ml of ultra-dry THF were added to the reaction flask, and the temperature was lowered to -70°C. n-Butyl lithium (58.4 ml, 0.146 mol, 1.06 eq) was added dropwise. After the addition was complete, the mixture was stirred for 1 h. Triisopropyl borate (39 g, 0.2085 mol, 1.5 eq) was added dropwise. After the addition was complete, the mixture was naturally warmed to room temperature and reacted overnight. Saturated aqueous ammonium chloride solution was added to the reaction solution, the liquids were separated, the aqueous phase was extracted once with EA, the organic phases were combined, concentrated to dryness, and dried with air at 65°C to obtain about 32 g of product 1-c with a yield of 78.3%.

[0068] Under nitrogen protection, the reaction flask was added with intermediate 1-d (32 g, 0.109 mol, 1 eq), intermediate 1-b (27.58 g, 0.109 mol, 1 eq), 300 ml of toluene, 150 ml of ethanol, potassium carbonate (37.95 g, 0.275 mol, 2.5 eq), 150 ml of water, and tetrakistriphenylphosphine palladium (1.27 g, 0.0011 mol, 1% eq). After the addition was completed, the reaction solution was heated and refluxed to react overnight. The reaction was completed by sampling HPLC. The reaction solution was cooled, water was added, and suction was filtered. The filter cake was washed with water and ethanol, and dried at 85°C. About 33 g of product 1-e was obtained, and the yield was 71.9%.

[0069] Under nitrogen protection, the reaction flask was added with intermediate 1-e (33 g, 0.078 mol, 1 eq), 3-bromo-N-phenylcarbazole 1-f (25.25 g, 0.078 mol, 1 eq), 600 ml of toluene, sodium tert-butoxide (9 g, 0.0936 mol, 1.2 eq), palladium acetate (0.35 g, 0.00156 mol, 2% eq), and X-phos (1.48 g, 0.00312 mol, 4%). After the addition was completed, the reaction solution was heated and refluxed to react overnight. The reaction was completed after sampling and HPLC detection. The reaction solution was cooled, water was added, the liquid was separated, filtered through silica gel, concentrated to dryness, and column chromatography was performed to obtain about 20 g of compound 6 with a yield of 38.7%.

[0070] The following compounds were obtained in a similar manner, as shown in Table 1 and Table 2:

[0071] Table 1 Raw materials, compounds and yields of Examples 2-9

[0072]

[0073] Table 2 Raw materials, compounds and yields of Examples 10-18

[0074]

[0075] The synthetic identification results of the compounds prepared above are shown in Table 3 below:

[0076] Table 3 Synthesis and identification results of compounds in Examples 1-18

[0077]

[0078] The thermal weight loss temperature Td and the glass transition temperature Tg of compounds 4, 5, 6, 14, 18, 36, 41, 49, 50, 51, 52, 54, 55, 60, 67, 74, 88, and 95 in Examples 1 to 18 of the present invention were tested. The results are shown in Table 4:

[0079] Note: The thermal weight loss temperature Td is the temperature at which the weight loss is 5% in a nitrogen atmosphere. It is measured on a TGA N-1000 thermogravimetric analyzer with a nitrogen flow rate of 10 mL / min. The Tg (glass transition temperature) is measured by differential scanning calorimetry (DSC, Shinco DSC N-650) with a heating rate of 10°C / min.

[0080] Table 4 Thermal weight loss temperature Td and glass transition temperature Tg of the compounds in Examples 1-18

[0081]

[0082] As can be seen from Table 4 above, the compounds of the present invention have relatively high Td and Tg values, indicating that they have excellent thermal stability. Applying them to organic electroluminescent devices can effectively extend the service life of the organic electroluminescent devices and obtain better use effects.

[0083] Device performance test:

[0084] Application Example 1:

[0085] ITO was used as the reflective layer anode substrate material, and its surface was treated with water, acetone and N2 in sequence;

[0086] On top of the ITO anode substrate, 10 nm of HT-1 containing 3 wt% NDP-9 was deposited to form a hole injection layer (HIL);

[0087] 100 nm of HT-1 was evaporated on the hole injection layer (HIL) to form the first hole transport layer (HTL);

[0088] Vacuum evaporation of GP on the first hole transport layer (HTL) to form a second hole transport layer (GPL) with a thickness of 30 nm;

[0089] Compound 6 prepared in Example 1 of the present invention and G19 were co-evaporated at a mass ratio of 6:4 as the main luminescent material, and GD-1 was evaporated as a doping material (the amount of GD-1 was 8% of the total weight of compound 6 and G19) on the second hole transport layer (GPL) to form a luminescent layer with a thickness of 30 nm;

[0090] HB-1 was evaporated onto the light-emitting layer to obtain a hole blocking layer (HBL) with a thickness of 20 nm;

[0091] ET-1 and LiQ were co-evaporated onto the hole blocking layer (HBL) in a mass ratio of 5:5 to obtain an electron transport layer (ETL) with a thickness of 50 nm;

[0092] Magnesium (Mg) and silver (Ag) were mixed and evaporated on the electron transport layer (ETL) in a mass ratio of 9:1 to form an electron injection layer (EIL) with a thickness of 50 nm;

[0093] Thereafter, silver (Ag) is evaporated onto the electron injection layer to form a cathode with a thickness of 100 nm, and a DNTPD with a thickness of 50 nm is deposited on the cathode sealing layer. In addition, the cathode surface is sealed with a UV curable adhesive and a packaging film (seal cap) containing a dehumidifier to protect the organic electroluminescent device from being affected by oxygen or moisture in the atmosphere. Thus, an organic electroluminescent device is prepared.

[0094] .

[0095] Application Example 2-18:

[0096] Compounds 4, 5, 14, 18, 36, 41, 49, 50, 51, 52, 54, 55, 60, 67, 74, 88, and 95 in Examples 2-18 of the present invention are used to replace Compound 6 in Application Example 1, respectively. Other parts are consistent with Application Example 1, and organic electroluminescent devices of Application Examples 2-18 are prepared accordingly.

[0097] Comparative Examples 1-4:

[0098] The difference between Control Examples 1-4 and Application Example 1 is that Compound D1 in CN115368293A, Compound D2 in US20220399517A1, Compound D3 in CN115368293A, and Compound D4 in CN117800897A are used to replace Compound 6 in Application Example 1, and the rest is the same as Application Example 1.

[0099] The organic electroluminescent devices prepared in Application Examples 1-18 and Comparative Examples 1-4 were tested respectively, and the test results are shown in Table 5.

[0100] Table 5 Test results of organic electroluminescent devices in Application Examples 1-18 and Comparative Examples 1-4

[0101]

[0102] It can be seen from Table 5 above that applying the compound of the present invention to an organic electroluminescent device and using it as a main material of a light-emitting layer can improve the luminous efficiency of the organic electroluminescent device to a certain extent, reduce the starting voltage, and relatively reduce power consumption.

[0103] The organic electroluminescent devices prepared in the control examples 1-4 and the application examples 1-10 were subjected to luminescence lifetime tests to obtain luminescence lifetime T97% data (the time for the luminescence brightness to decrease to 97% of the initial brightness). The test equipment was a TEO luminescent device lifetime test system. The results are shown in Table 6:

[0104] Table 6 Test results of luminescence life of organic electroluminescent devices in comparative examples 1-4 and application examples 1-10

[0105]

[0106] It can be seen from Table 6 above that when the compound of the present invention is used as the main material of the light-emitting layer and applied to an organic electroluminescent device, the service life of the prepared organic electroluminescent device is greatly improved, so it has a very broad application prospect.

Claims

1. A compound containing a tricarbazole structure, characterized in that: Its structural formula is shown in Formula 2 below: ； A 1- A5 is independently selected from hydrogen, deuterium, deuterated or undeuterated phenyl, deuterated or undeuterated biphenyl; R1-R2 are each independently deuterium, deuterated or undeuterated phenyl, deuterated or undeuterated biphenyl; G is a substituted carbazolyl group, wherein the substituent is selected from one or more of deuterium, phenyl, and deuterated phenyl; n is an integer from 0 to 3; m is an integer from 0 to 7; p is 0 or 1.

2. The compound containing a tricarbazole structure according to claim 1, characterized in that The compound is any one of the following compounds: 。 3. An organic electroluminescent device, characterized in that: The invention comprises a first electrode, a second electrode and an organic layer formed between the first electrode and the second electrode; the organic layer contains the compound containing a tricarbazole structure as claimed in any one of claims 1 to 2.

4. The organic electroluminescent device according to claim 3, characterized in that: The organic layer comprises a hole injection layer, a first hole transport layer, a second hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer; The light-emitting layer contains a light-emitting host material, and the light-emitting host material is a mixture of the compound containing a tricarbazole structure according to any one of claims 1 to 2 and any one or more of compounds G1 to G51, and the compounds G1 to G51 are as follows: 。 5. An electronic display device, characterized in that: Contains the organic electroluminescent device as claimed in claim 3.

6. An OLED lighting device, characterized in that: Contains the organic electroluminescent device as claimed in claim 3.

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