A compound and its applications

Abstract

The present invention relates to a compound and its application, and the compound has a structure shown in Formula I. The compound provided by the present invention uses a large conjugated eight-membered aromatic ring with a specific structure as the mother nucleus, which improves the planarity of the molecule, reduces the carrier transport barrier, and cooperates with aryl or heteroaryl (Ar), which is beneficial to improving the luminous efficiency of the OLED device using the compound and reducing the driving voltage. In addition, the increase in conjugation makes the rigidity of the compound molecule stronger and the structure more stable, and the OLED device using the compound also exhibits a better lifespan.

Description

Technical Field

[0001] The present invention relates to the technical field of organic electroluminescence, and particularly to a compound and its application. Background Art

[0002] In recent years, optoelectronic devices based on organic materials have become increasingly popular. The inherent flexibility of organic materials makes them very suitable for manufacturing on flexible substrates, and beautiful and cool optoelectronic products can be designed and produced according to requirements, obtaining incomparable advantages over inorganic materials. Examples of such organic optoelectronic devices include organic light-emitting diodes (OLEDs), organic field-effect transistors, organic photovoltaic cells, organic sensors, etc. Among them, the development of OLEDs has been particularly rapid and has achieved commercial success in the field of information display. OLEDs can provide three colors of high saturation, red, green, and blue. The full-color display device made of them does not require an additional backlight source and has the advantages of gorgeous colors, lightness, and softness.

[0003] The core of an OLED device is a thin-film structure containing various organic functional materials. Common functional organic materials include: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, as well as light-emitting host materials and light-emitting guests (dyes), etc. When powered on, electrons and holes are respectively injected, transported to the light-emitting region and recombined here, thereby generating excitons and emitting light.

[0004] People have developed a variety of organic materials. Combining various peculiar device structures can improve the carrier mobility, regulate the carrier balance, break through the electroluminescence efficiency, and delay the device decay. For quantum mechanical reasons, common fluorescent emitters mainly utilize singlet excitons generated when electrons and holes combine and are still widely used in various OLED products. Some metal complexes such as iridium complexes can emit light by simultaneously utilizing triplet excitons and singlet excitons and are called phosphorescent emitters. Their energy conversion efficiency can be increased by up to four times compared with traditional fluorescent emitters. Thermally activated delayed fluorescence (TADF) technology can still effectively utilize triplet excitons to achieve high luminescence efficiency without using metal complexes by promoting the conversion of triplet excitons to singlet excitons. Thermally activated sensitized fluorescence (TASF) technology uses materials with TADF properties to sensitize emitters through energy transfer and can also achieve high luminescence efficiency.

[0005] However, existing organic electroluminescent materials are still unsatisfactory in terms of operating voltage, luminescence efficiency, service life, etc. Therefore, the industry urgently needs to develop new material systems to meet the increasing requirements for the optoelectronic performance and service life of OLED devices. Summary of the Invention

[0006] One of the objectives of the present invention is to provide a compound which has a high molecular planarity, can reduce the carrier transport barrier, not only can improve the performance of the OLED device, but also has strong chemical stability and thermal stability.

[0007] To achieve this purpose, the present invention adopts the following technical solutions:

[0008] The present invention provides a compound which has a structure shown in Formula I;

[0009]

[0010] In Formula I, L is selected from a single bond, a substituted or unsubstituted C6-C30 arylene group, or a substituted or unsubstituted C3-C30 heteroarylene group;

[0011] In Formula I, Ar is selected from a substituted or unsubstituted C6-C30 aryl group or a substituted or unsubstituted C3-C30 heteroaryl group;

[0012] In Formula I, the X 1 ~X 6 are independently selected from CR 1 or N, and the R 1 are independently selected from hydrogen, a substituted or unsubstituted C1-C10 linear alkyl group, a substituted or unsubstituted C3-C10 cycloalkyl group, a substituted or unsubstituted C1-C10 linear alkoxy group, a substituted or unsubstituted C3-C10 cycloalkoxy group, a substituted or unsubstituted C2-C10 alkenyl group, a substituted or unsubstituted C2-C10 alkynyl group, a halogen, a cyano group, a nitro group, a hydroxyl group, a silyl group, an amino group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C6-C30 arylamino group, a substituted or unsubstituted C3-C30 heteroarylamino group, or a substituted or unsubstituted C3-C30 heteroaryl group; when there are at least two R 1 s, these at least two R 1 are the same or different;

[0013] In Formula I, the ring A and the ring B are independently selected from a substituted or unsubstituted C6-C30 aromatic ring or a substituted or unsubstituted C3-C30 heteroaromatic ring; the ring A and the ring B are fused with an eight-membered ring;

[0014] When the above groups have substituents, the substituents are selected from one or a combination of at least two of halogen, cyano, C1-C10 linear alkyl, C3-C10 cycloalkyl, C1-C6 alkoxy, C1-C6 thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aryl, C10-C30 fused-ring aryl, C3-C30 monocyclic heteroaryl, and C6-C30 fused-ring heteroaryl. When the expression "substituted or unsubstituted" is involved in the present invention, the substituents all have the above selection range.

[0015] The present invention provides a novel compound, with a large conjugated octa-aryl ring of a specific structure as the mother nucleus, which improves the planarity of the molecule, reduces the carrier transport barrier, and in combination with aryl or heteroaryl (Ar), is beneficial to improving the luminous efficiency of the OLED device using the compound and reducing the driving voltage. In addition, the increase in conjugation makes the rigidity of the compound molecule stronger and the structure more stable, and better lifetime is also shown in the OLED device using the compound.

[0016] In the present invention, the number of carbon atoms in the C1-C10 linear alkyl can be C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.; the number of carbon atoms in the C3-C10 cycloalkyl can be C4, C5, C6, C7, C8, C9, C10, etc.; the number of carbon atoms in the C1-C10 linear alkoxy can be C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.; the number of carbon atoms in the C3-C10 cycloalkoxy can be C4, C5, C6, C7, C8, C9, C10, etc.; the number of carbon atoms in the C6-C30 arylamino can be C10, C12, C14, C16, C18, C20, C26, C28, etc.; the number of carbon atoms in the C3-C30 heteroarylamino can be C6, C8, C10, C12, C14, C16, C18, C20, C26, C28, etc.; the number of carbon atoms in the C6-C30 aryl can be C10, C12, C14, C16, C18, C20, C26, C28, etc.; the number of carbon atoms in the C3-C30 heteroaryl can be C6, C8, C10, C12, C14, C16, C18, C20, C26, C28, etc.; the number of carbon atoms in the C2-C10 alkenyl can be C2, C3, C4, C5, C6, C7, C8, C9, C10, etc.; the number of carbon atoms in the C2-C10 alkynyl can be C2, C3, C4, C5, C6, C7, C8, C9, C10, etc. The above carbon numbers are only examples and are not limited to the above.

[0017] Preferably, the compound has the structure shown in Formula II;

[0018]

[0019] In Formula II, the X 7 ~X14 Independently selected from CR 2 or N, and said R 2 is independently selected from one of hydrogen, halogen, cyano, C1-C10 linear alkyl, C3-C10 cycloalkyl, C1-C6 alkoxy, C1-C6 thioalkoxy, C6-C30 arylamino, C3-C30 heteroarylamino, C6-C30 monocyclic aryl, C10-C30 fused-ring aryl, C3-C30 monocyclic heteroaryl, C6-C30 fused-ring heteroaryl, and said R 2 is fused or not fused to the adjacent aromatic ring;

[0020] Said X 1 ~X 6 , Ar and L have the same meanings as described above.

[0021] Preferably, ring A and ring B are independently selected from a substituted or unsubstituted benzene ring or a substituted or unsubstituted pyridine ring.

[0022] Preferably, at most one of said X 7 ~X 14 is N, and preferably said X 7 ~X 14 are all CR 2 .

[0023] Preferably, the compound has the structure shown in Formula III-1 to Formula III-5;

[0024]

[0025] Said X 1 ~X 6 , L and Ar have the same meanings as described above.

[0026] Preferably, the compound has the structure shown in Formula III-1.

[0027] Preferably, said X 1 ~X 6 are all CR 1 .

[0028] Preferably, said R 1 is independently selected from one of hydrogen, cyano, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroaryl, substituted or unsubstituted C3-C30 heteroarylamino, and more preferably hydrogen.

[0029] Preferably, L is selected from one of a single bond, phenylene, biphenylene or naphthylene.

[0030] Preferably, the Ar is selected from substituted or unsubstituted electron-deficient heteroaryl groups having 3 to 30 carbon atoms.

[0031] An electron-deficient heteroaryl group is an electron-withdrawing heteroaryl group, which is a heteroaryl group in which the electron cloud density on the benzene ring decreases after the substituent replaces the hydrogen on the benzene ring.

[0032] In the present invention, it is preferred that Ar is an electron-deficient heteroaryl group, which can further improve the performance of the device when combined with the large conjugated eight-membered aromatic ring parent nucleus.

[0033] Preferably, the Ar has one of the structures shown in the following (3-1) to (3-4):

[0034]

[0035] In formula (3-1), the Z 1 , Z 2 , Z 3 , Z 4 and Z 5 each independently represents CR 3 or an N atom, and at least one of Z 1 , Z 2 , Z 3 , Z 4 and Z 5 is an N atom.

[0036] In formula (3-2), the Z 6 , Z 7 , Z 8 , Z 9 , Z 10 , Z 11 , Z 12 and Z 13 each independently represents CR 3 or an N atom, and at least one of Z 6 , Z 7 , Z 8 , Z 9 , Z 10 , Z 11 , Z 12 and Z 13 is an N atom.

[0037] In formula (3-3), the Z 14 , Z 15 , Z 16 , Z 17 , Z 18 , Z 19 , Z 20 , Z 21 , Z 22 and Z 23 each independently represents CR3 or an N atom, and Z 14 、Z 15 、Z 16 、Z 17 、Z 18 、Z 19 、Z 20 、Z 21 、Z 22 and Z 23 at least one of them is an N atom,

[0038] In formula (3-4), Z 24 、Z 25 、Z 26 、Z 27 、Z 28 、Z 29 、Z 30 、Z 31 、Z 32 and Z 33 each independently selected from CR 3 or an N atom, and Z 24 、Z 25 、Z 26 、Z 27 、Z 28 、Z 29 、Z 30 、Z 31 、Z 32 and Z 33 at least one of them is an N atom,

[0039] The said R 3 is selected from one of hydrogen, substituted or unsubstituted C1-C12 linear alkyl, substituted or unsubstituted C3-C12 cycloalkyl, substituted or unsubstituted C1-C12 alkoxy, halogen, cyano, nitro, hydroxyl, silyl, amino, substituted or unsubstituted C6-C30 arylamino, substituted or unsubstituted C3-C30 heteroarylamino, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C3-C30 heteroaryl;

[0040] Wherein, * represents the bonding site of the group.

[0041] Preferably, the said Ar has the structure shown in (3-1) or (3-2).

[0042] Preferably, in formula (3-1), Z 1 、Z 2 、Z 3 、Z 4 and Z 5 at least two of them are N atoms;

[0043] and / or, in formula (3-2), Z 6, Z 7 , Z 8 , Z 9 , Z 10 , Z 11 , Z 12 and Z 13 At least two of them are N atoms.

[0044] Preferably, the Ar is selected from one of the following substituted or unsubstituted groups: pyridyl, quinolinyl, quinazolinyl, triazinyl, pyrimidinyl or quinoxalinyl.

[0045] Preferably, the Ar is selected from one of the A1-A14 groups which are substituted or unsubstituted:

[0046]

[0047]

[0048] wherein, * represents the bonding site of the group.

[0049] Preferably, the Ar is selected from one of the B1-B19 groups:

[0050]

[0051] Preferably, the compound has one of the structures shown in P1-P127 as follows:

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059] The second object of the present invention is to provide an application of the compound described in the first object, and the compound is applied to an organic electroluminescent device.

[0060] Preferably, the compound is used as a light-emitting layer material of the organic electroluminescent device, preferably as a host material of the light-emitting layer.

[0061] A third object of the present invention is to provide an organic electroluminescent device, which includes a substrate, a first electrode, a second electrode, and at least one organic layer located between the first electrode and the second electrode, and the organic layer contains at least one of the compounds described in one of the objects.

[0062] Preferably, the organic layer includes a light-emitting layer, and the light-emitting layer contains at least one of the compounds described in one of the objects.

[0063] Preferably, the compound serves as a host material of the light-emitting layer.

[0064] Specifically, an organic electroluminescent device (OLED) includes a first electrode and a second electrode, and an organic material layer located between the electrodes. The organic material can be further divided into multiple regions. For example, the organic material layer can include a hole transport region, a light-emitting layer, and an electron transport region.

[0065] In a specific embodiment, a substrate can be used under the first electrode or above the second electrode. The substrate is made of glass or polymer materials with excellent mechanical strength, thermal stability, water resistance, and transparency. In addition, a thin-film transistor (TFT) can also be provided on the substrate for display purposes.

[0066] The first electrode can be formed by sputtering or depositing a material used as the first electrode on the substrate. When the first electrode serves as an anode, oxide transparent conductive materials such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO), etc., and any combination thereof can be used. When the first electrode serves as a cathode, metals or alloys such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), etc., and any combination thereof can be used.

[0067] The organic material layer can be formed on the electrode by methods such as vacuum thermal evaporation, spin coating, printing, etc. The compounds used as the organic material layer can be organic small molecules, organic macromolecules, polymers, and combinations thereof.

[0068] The hole transport region is located between the anode and the light-emitting layer. The hole transport region can be a single-layer hole transport layer (HTL), including a single-layer hole transport layer containing only one compound and a single-layer hole transport layer containing multiple compounds. The hole transport region can also be a multi-layer structure including at least one of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL).

[0069] The material of the hole transport region can be selected from, but not limited to, phthalocyanine derivatives such as CuPc, conductive polymers, or polymers containing conductive dopants such as poly(phenylene vinylene), polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives such as the compounds shown as HT-1 to HT-34 below; or any combination thereof.

[0070]

[0071]

[0072] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can adopt one or more of the compounds of HT-1 to HT-34 above, or one or more of the compounds of HI-1 to HI-3 below; it can also adopt one or more of the compounds of HT-1 to HT-34 doped with one or more of the compounds of HI-1 to HI-3.

[0073]

[0074] The light-emitting layer includes light-emitting dyes (i.e., dopants, Dopant) that can emit spectra of different wavelengths, and can also include a host material (Host) at the same time. The light-emitting layer can be a single-color light-emitting layer that emits a single color such as red, green, or blue. Multiple single-color light-emitting layers of different colors can be arranged in a planar pattern according to a pixel pattern, or stacked together to form a color light-emitting layer. When the light-emitting layers of different colors are stacked together, they can be separated from each other or connected to each other. The light-emitting layer can also be a single color light-emitting layer that can simultaneously emit different colors such as red, green, and blue.

[0075] According to different technologies, the light-emitting layer material can adopt different materials such as fluorescent electroluminescent materials, phosphorescent electroluminescent materials, thermally activated delayed fluorescence luminescent materials, etc. In an OLED device, a single light-emitting technology can be adopted, or a combination of multiple different light-emitting technologies can be adopted. These different light-emitting materials classified by technology can emit light of the same color or different colors.

[0076] In one aspect of the present invention, the light-emitting layer adopts the technology of phosphorescent electroluminescence. The phosphorescent dopant of the light-emitting layer can be selected from, but not limited to, one or more combinations of the following listed RPD-1 to RPD-28.

[0077]

[0078]

[0079] The OLED organic material layer may further include an electron transport region between the light-emitting layer and the cathode. The electron transport region may be a single-layer electron transport layer (ETL), including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing multiple compounds. The electron transport region may also be a multi-layer structure including at least one layer of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0080] In one aspect of the present invention, the electron transport layer material may be selected from, but not limited to, one or a combination of more than one of ET-1 to ET-57 listed below.

[0081]

[0082]

[0083]

[0084] The device may further include an electron injection layer between the electron transport layer and the cathode. The electron injection layer material includes, but is not limited to, one or a combination of more than one of the following listed: LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, and / or Ca.

[0085] Compared with the prior art, the present invention has the following beneficial effects:

[0086] The present invention provides a novel compound with a large conjugated octa-aryl ring with a specific structure as the mother nucleus, which improves the planarity of the molecule, reduces the carrier transport barrier, and in combination with an aryl or heteroaryl (Ar), is beneficial to improving the luminous efficiency of the OLED device using the compound and reducing the driving voltage. In addition, the increase in conjugation makes the compound molecule more rigid and the structure more stable, and the device using the compound also exhibits a better lifespan. Detailed Embodiments

[0087] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations to the present invention.

[0088] The representative synthesis route of the compound of Formula II of the present invention is as follows:

[0089]

[0090] The above X 1 ~X 14, both Ar and L have the same meanings as in Formula II.

[0091] To enable those skilled in the art to better understand the present invention, the following will take multiple synthesis examples to detail the specific preparation methods of the above compounds of the present invention. However, the preparation methods of the present invention are not limited to these multiple synthesis examples. Those skilled in the art can make any modifications, equivalent substitutions, improvements, etc. on this basis without departing from the principles of the present invention, and extend the method to the scope of the technical solutions claimed in the claims of the present invention.

[0092] Compounds of synthesis methods not mentioned in the present invention are all raw material products obtained through commercial channels. Solvents and reagents used in the present invention, such as dichloromethane, ethanol, N,N-dimethylformamide (DMF), quinazoline, triazine, quinoxaline and other chemical reagents, can all be purchased from the domestic chemical product market, such as purchased from Sinopharm Chemical Reagent Co., Ltd., TCI Co., Ltd., Shanghai Bide Pharmaceutical Co., Ltd., J&K Scientific Ltd., Zhengzhou Haikuo, etc. In addition, those skilled in the art can also synthesize them through well-known methods.

[0093] Synthesis of Intermediate M:

[0094]

[0095] 4,5-Dibromocarbazole (1 mol), phenylboronic acid (1 mol), potassium carbonate (1.2 mol), tetrakis(triphenylphosphine)palladium (0.01 mmol), 1000 mol of dioxane, and 100 mL of water were added to a reaction flask, heated to reflux for 6 h, monitored by TLC until the reaction was complete, and extracted with ethyl acetate and water. The organic phase was concentrated to obtain Intermediate M-A.

[0096] M-A (0.5 mol), 2-amino-phenylboronic acid pinacol ester (0.7 mol), potassium carbonate (1.0 mol), tetrakis(triphenylphosphine)palladium (0.005 mmol), 800 mol of dioxane, and 80 mL of water were added to a reaction flask, heated to reflux for 5 h, monitored by TLC until the reaction was complete, and extracted with ethyl acetate and water. The organic phase was concentrated and purified by column chromatography to obtain Intermediate M-B.

[0097] M-B (0.3 mol) was added to 500 mL of acetic acid, copper powder (1.2 mol) was added, and tert-butyl nitrite (1 mol) was added dropwise at 20 °C. After the addition was complete, the reaction was carried out at room temperature for 4 h, monitored by TLC until the reaction was complete, and extracted with water and dichloromethane. The separated organic phase was concentrated and purified by column chromatography to obtain Intermediate M.

[0098] By the same method, phenylboronic acid in the above reaction was replaced with an equivalent amount of 2-pyridineboronic acid to obtain Intermediate M1:

[0099]

[0100] By the same method, phenylboronic acid in the above reaction was replaced with an equivalent amount of 3-pyridineboronic acid to obtain intermediates M2 and M3 respectively:

[0101] (M2 and M3 were separated by column chromatography).

[0102] By the same method, phenylboronic acid in the above reaction was replaced with an equivalent amount of 4-pyridineboronic acid to obtain intermediate M4:

[0103]

[0104] Synthesis Example 1: Synthesis of Compound P6

[0105]

[0106] M (50 mmol), 2-chloro-4-phenylquinazoline (55 mmol), cesium carbonate (60 mmol), and N,N-dimethylformamide (DMF, 150 mL) were added to a reaction flask, and the mixture was refluxed for 4 h. After the reaction was complete, the temperature was lowered to room temperature. The reaction mixture was poured into water and filtered. The filter cake was washed once with ethanol and then recrystallized from toluene to obtain compound P6.

[0107] Synthesis Example 2: Synthesis of Compound P18

[0108]

[0109] M (50 mmol), 2-(4-fluorophenyl)-4-phenylquinazoline (55 mmol), cesium carbonate (60 mmol), and DMF (150 mL) were added to a reaction flask, and the mixture was refluxed for 4 h. After the reaction was complete, the temperature was lowered to room temperature. The reaction mixture was poured into water and filtered. The filter cake was washed once with ethanol and then recrystallized from toluene to obtain compound P18.

[0110] Synthesis Example 3: Synthesis of Compound P24

[0111] The difference in the synthesis method from Synthesis Example 1 was that 2-chloro-4-phenylquinazoline was replaced with an equivalent amount of 2-chloro-3-(1-naphthyl)quinoxaline to obtain compound P24.

[0112] Synthesis Example 4: Synthesis of Compound P40

[0113] The difference in the synthesis method from Synthesis Example 1 was that 2-chloro-4-phenylquinazoline was replaced with an equivalent amount of 2-(2-fluorophenyl)-4,6-diphenyl-1,3,5-triazine to obtain compound P40.

[0114] Synthesis Example 5: Synthesis of Compound P80

[0115] The difference between the synthesis method and that of Synthesis Example 1 is that 2-chloro-4-phenylquinazoline is replaced with an equivalent amount of 2-chloro-3-(3-biphenyl)quinoxaline, and M is replaced with an equivalent amount of M4 to obtain Compound P80.

[0116] Synthesis Example 6: Synthesis of Compound P84

[0117] The difference between the synthesis method and that of Synthesis Example 1 is that 2-chloro-4-phenylquinazoline is replaced with an equivalent amount of 2-chloro-4,6-diphenyl-1,3,5-triazine, and M is replaced with an equivalent amount of M1 to obtain Compound P80.

[0118] Synthesis Example 7: Synthesis of Compound P49

[0119] The difference between the synthesis method and that of Synthesis Example 1 is that M is replaced with an equivalent amount of M2.

[0120] Synthesis Example 8: Synthesis of Compound P64

[0121] The difference between the synthesis method and that of Synthesis Example 1 is that M is replaced with an equivalent amount of M3.

[0122] To verify the certainty of the above molecular structure, we confirmed it by elemental analysis (measurement instrument: Thermo Fisher FLASH 2000 CHNS / O organic elemental analyzer) and mass spectrometry information (measurement instrument: measured by ZAB-HS type mass spectrometer, manufactured by Micromass UK Ltd.), as shown in Table 1 specifically.

[0123] Table 1

[0124] Compound Elemental analysis (%) Mass spectrometry P6 C, 87.48; H, 4.45; N, 8.07 522.2 P18 C, 88.41; H, 4.56; N, 7.03 598.2 P24 C, 88.25; H, 4.40; N, 7.37 572.2 P40 C, 86.52; H, 4.52; N, 8.96 625.2 P80 C, 86.25; H, 4.38; N, 9.37 599.29 P84 C, 83.05; H, 4.23; N, 12.72 550.2 P49 C, 85.02; H, 4.25; N, 10.73 522.2 P64 C, 85.02; H, 4.25; N, 10.73 522.2

[0125] Example 1

[0126] This example provides an organic electroluminescent device, and the preparation process is as follows:

[0127] The glass plate coated with the ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture is completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam on the surface;

[0128] Place the above glass substrate with the anode in a vacuum chamber, evacuate to <1×10 -5Pa, a 10-nm-thick mixture of HT-4:HI-3 (97 / 3, w / w) was vacuum thermally evaporated in sequence on the above-mentioned anode layer film as a hole injection layer, a 60-nm-thick compound HT-4 as a hole transport layer, a 40-nm-thick binary mixture of compound P6:RPD-8 (100:3, w / w) as a light-emitting layer, a 25-nm-thick mixture of compound ET-46:ET-57 (50 / 50, w / w) as an electron transport layer, a 1-nm-thick LiF as an electron injection layer, and a 150-nm-thick metal aluminum as a cathode. The total evaporation rate of all organic layers and LiF was controlled at 0.1 nm / second, and the evaporation rate of the metal electrode was controlled at 1 nm / second.

[0129] Examples 2 to 13 and Comparative Examples 1 to 2 are different from Example 1 only in that the host material P6 of the light-emitting layer is replaced with other compounds. For details, see Table 2.

[0130] Among them, the structures of the host materials in the comparative examples are as follows:

[0131]

[0132] Compounds C1 and C2 are described in detail in Patent KR1020150086069A and KR1020190085878A, respectively.

[0133] Performance Test

[0134] The following performance measurements were carried out on the organic light-emitting devices of the examples and comparative examples, respectively:

[0135] At the same brightness, a digital source meter and a luminance meter were used to measure the driving voltage, current efficiency, and lifetime of the organic light-emitting devices prepared in the examples and comparative examples. Specifically, the voltage was increased at a rate of 0.1 V per second, and the voltage when the brightness of the organic light-emitting device reached 3000 cd / m 2 was measured as the driving voltage, and the current density at this time was also measured; the ratio of brightness to current density is the current efficiency. The LT95 lifetime test is as follows: Using a luminance meter at a brightness of 10000 cd / m 2 and keeping a constant current, the time when the brightness of the organic light-emitting device dropped to 9500 cd / m 2 was measured, and the unit is hours. The results are shown in Table 2. Among them, the current efficiency and lifetime of the device in Comparative Example 1 were set to 100%, and the values of other compounds are all relative values to it.

[0136] Table 2

[0137]

[0138]

[0139] As can be seen from Table 2, when the compound of Formula I provided by the present invention is used as the host material of the light-emitting layer of an organic electroluminescent device, the device simultaneously has a high current efficiency, a low driving voltage, and a long service life, wherein the driving voltage is 3.5 - 3.8V.

[0140] Although the host materials C1 and C2 in the comparative examples also contain large conjugated octacyclic rings, the parent nucleus contains two carbazole groups. Although the voltage is at the same level as that in the examples, the current efficiency and lifespan of the device are worse than those in the examples. Analyzing the reasons, it may be that the comparative compound has a structure in which two carbazoles are connected. The molecule has an imbalance in the transport of holes and electrons, and its ability to accept holes is stronger than its ability to accept electron energy levels. This imbalance in transport affects the formation of excitons in the light-emitting layer, resulting in low efficiency and a shortened lifespan. Thus, it can be seen that not all compounds with a large conjugated parent nucleus can achieve the technical effects of the present invention when used as the host material.

[0141] The present invention uses the above-mentioned examples to illustrate the detailed method of the present invention, but the present invention is not limited to the above detailed method, that is, it does not mean that the present invention must rely on the above detailed method 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 compound, characterized in that, The compound has a structure represented by any one of Formula III-1 to Formula III-4; L is selected from one of a single bond, a phenylene group, a biphenylene group or a naphthylene group; The said X 1 ~X 6 is independently selected from CR 1 , and the said R 1 is independently selected from one of hydrogen, C1-C10 linear alkyl, C1-C10 linear alkoxy, halogen, cyano, substituted or unsubstituted C6-20 aryl, substituted or unsubstituted C6-C20 arylamino, and substituted or unsubstituted C3-C20 heteroaryl; Ar is selected from one of the following substituted or unsubstituted groups: a C6-C16 aryl group, a quinazolinyl group, a triazinyl group, a pyrimidinyl group or a quinoxalinyl group; When the above groups have substituents, the substituents are selected from one of a halogen, a cyano group, a C1-C10 linear alkyl group, a C1-C6 alkoxy group, a C6-C30 monocyclic aryl group, a C10 fused-ring aryl group or a combination of at least two of them.

2. The compound according to claim 1, wherein The compound has a structure represented by Formula III-1.

3. The compound according to claim 1, wherein The R 1 is independently selected from one of hydrogen, cyano group, substituted or unsubstituted C6-C20 aryl group, substituted or unsubstituted C6-C20 arylamino group, and substituted or unsubstituted C3-C20 heteroaryl group.

4. The compound according to claim 1, wherein The said R 1 is hydrogen.

5. A compound, characterized in that, The compound has a structure represented by any one of Formula III-1 to Formula III-4; L is selected from one of a single bond, a phenylene group, a biphenylene group or a naphthylene group; The said X 1 ~X 6 is independently selected from CR 1 , and the said R 1 is independently selected from one of hydrogen, C1-C10 linear alkyl, C1-C10 linear alkoxy, halogen, cyano, substituted or unsubstituted C6-20 aryl, substituted or unsubstituted C6-C20 arylamino, and substituted or unsubstituted C3-C20 heteroaryl; when the above groups have substituents, the substituents are selected from one of halogen, cyano, C1-C10 linear alkyl, C1-C6 alkoxy, C6-C30 monocyclic aryl, and C10 fused-ring aryl, or a combination of at least two of them; Ar is selected from one of the groups A1 to A14: wherein, * represents the bonding site of the group.

6. A compound, characterized in that, The compound has a structure represented by any one of Formula III-1 to Formula III-4; L is selected from one of a single bond, a phenylene group, a biphenylene group or a naphthylene group; The said X 1 ~X 6 is independently selected from CR 1 , and the said R 1 is independently selected from one of hydrogen, C1-C10 linear alkyl, C1-C10 linear alkoxy, halogen, cyano, substituted or unsubstituted C6-20 aryl, substituted or unsubstituted C6-C20 arylamino, and substituted or unsubstituted C3-C20 heteroaryl; when there are substituents in the above groups, the substituents are selected from one of halogen, cyano, C1-C10 linear alkyl, C1-C6 alkoxy, C6-C30 monocyclic aryl, and C10 fused-ring aryl, or a combination of at least two of them; Ar is selected from one of the groups B1 to B19:

7. A compound, characterized in that, The compound has one of the following structures:

8. Use of a compound according to any one of claims 1 to 7, characterized in that, The compound is applied to an organic electroluminescent device.

9. The application according to claim 8, wherein The compound is used as a light-emitting layer material of the organic electroluminescent device.

10. The application according to claim 8, characterized in that The compound is used as a host material for the light-emitting layer.

11. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes a substrate, a first electrode, a second electrode and at least one organic layer located between the first electrode and the second electrode, and the organic layer contains at least one compound according to any one of claims 1 to 7.

12. The organic electroluminescent device according to claim 11, wherein The organic layer includes a light-emitting layer, and the light-emitting layer contains at least one compound according to any one of claims 1 to 7.

13. The organic electroluminescent device according to claim 12, wherein The compound is used as the host material for the light-emitting layer.

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