Organic electroluminescent compound as well as preparation method and application thereof

Abstract

The invention belongs to the field of organic electroluminescent materials, and particularly relates to an organic electroluminescent compound as well as a preparation method and application thereof. The compound provided by the invention has a structure as shown in a formula 1, and has the advantages that the compound can be used as a blue light or dark blue light luminescent material of an organic electroluminescent device, so that the defects of the existing blue light luminescent material are overcome; as a luminescent material, the compound has very matched hole-electron transmission rate, and is beneficial to improving the luminescent efficiency of the material and the stability of a device; in addition, the driving service life of the display device is prolonged; the organic light-emitting diode material has a very high radiative transition rate constant, and is beneficial to prolonging the driving period of an organic light-emitting diode device. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the field of organic electroluminescent materials, and particularly relates to an organic electroluminescent compound, a preparation method thereof and an application thereof. Background Art

[0002] In recent years, organic light-emitting diodes having electroluminescent properties have been intensively studied and developed. In the basic structure of an organic light-emitting diode element, a thin film layer containing a light-emitting material is disposed between a first electrode and a second electrode, and by applying a voltage to the element, light emission is obtained from the light-emitting material.

[0003] Due to the above-mentioned self-luminous characteristics of the organic light-emitting diode element, it has advantages such as high pixel visibility and no need for a backlight source compared with a liquid crystal display, and thus is extremely suitable as a flat panel display element. Thinness, lightness and fast response are the advantages of the organic light-emitting diode element. In addition, since the organic light-emitting diode element can also be in the form of a thin film, it is also possible to use the organic light-emitting diode to achieve large-area planar light emission and a surface light source for a lighting lamp.

[0004] The working principle of an organic light-emitting diode is: it is driven by injecting electrons from the cathode and holes from the anode into a thin film layer containing a light-emitting material between a pair of electrodes. The electrons injected from the cathode and the holes injected from the anode recombine in the thin film layer containing the light-emitting material to form a molecular excited state, and the molecular excited state releases energy and then returns to the ground state. The excited state of an organic compound can be a singlet excited state or a triplet excited state, and light emission can be generated from any excited state.

[0005] The emission wavelength of a light-emitting element is determined by the energy difference between the ground state and the excited state, that is, the energy gap. Therefore, by appropriately selecting or modifying the molecular structure that generates light emission, light of any color can be obtained. When a light-emitting device is manufactured using light-emitting elements that can emit red, blue and green light (the three primary colors of light), the light-emitting device can display full color. Therefore, manufacturing a high-performance full-color light-emitting device requires red, blue and green light-emitting materials, and these light-emitting materials are required to have good lifetimes and emission efficiencies. In recent years, many excellent red and green light-emitting materials have been obtained in this field. However, blue light-emitting materials with good luminous lifetimes and emission efficiencies still need to be developed. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide, in view of the deficiencies of the prior art, an organic electroluminescent element material having high luminous efficiency, low driving voltage, long lifetime, small voltage rise amplitude during driving and further high-timeliness stability, which can be used as a blue light-emitting material, and can increase the efficiency of an organic light-emitting device and extend its half-life, having economic advantages for industrial applications.

[0007] To solve the above technical problems, the present invention discloses an organic electroluminescent compound, and the structure of the organic electroluminescent compound is shown in Formula 1:

[0008]

[0009] Wherein, R 1 -R 4 are each independently selected from hydrogen, deuterium, halogen, cyano, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, and a substituted or unsubstituted heteroaryl group having 5 to 60 carbon atoms;

[0010] R 5 is different from any one of R 1 -R 4 Specifically, R 5 is selected from the structure shown in Formula 1-R 5 as follows:

[0011]

[0012] L is selected from a single bond, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroarylene group having 3 to 30 carbon atoms;

[0013] Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms;

[0014] R 6 to R 8 are each independently hydrogen, deuterium, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted heterocyclic group having 3 to 30 carbon atoms;

[0015] Wherein, r 6 is an integer from 0 to 7, r 7 and r 8 are each an integer from 0 to 8; when r 6 to r 8 are each 2, R 6 and R 8 are the same as or different from each other.

[0016] Preferably, the structure of the organic electroluminescent compound is shown in Formulas 1-1 to 1-4:

[0017]

[0018] Preferably, at least one of R 1 -R 4 is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms. At this time, R1 -R 4 The other positions in 4 are hydrogen;

[0019] More preferably, at least one of R 1 -R 4 is selected from substituted or unsubstituted aryl groups having 6 to 25 carbon atoms and substituted or unsubstituted heteroaryl groups having 3 to 25 carbon atoms. At this time, the other positions in R 1 -R 4 are hydrogen;

[0020] Even more preferably, at least one of R 1 -R 4 is selected from substituted or unsubstituted aryl groups having 6 to 20 carbon atoms and substituted or unsubstituted heteroaryl groups having 3 to 20 carbon atoms. At this time, the other positions in R 1 -R 4 are hydrogen.

[0021] Preferably, L is selected from a single bond, substituted or unsubstituted arylene groups having 6 to 25 carbon atoms, and substituted or unsubstituted heteroarylene groups having 3 to 25 carbon atoms; Ar is selected from substituted or unsubstituted aryl groups having 6 to 25 carbon atoms and substituted or unsubstituted heteroaryl groups having 3 to 25 carbon atoms;

[0022] More preferably, L is selected from a single bond, substituted or unsubstituted arylene groups having 6 to 20 carbon atoms, and substituted or unsubstituted heteroarylene groups having 3 to 20 carbon atoms; Ar is selected from substituted or unsubstituted aryl groups having 6 to 20 carbon atoms and substituted or unsubstituted heteroaryl groups having 3 to 20 carbon atoms.

[0023] Among them, the substituents of the R 1 , R 2 , R 3 , R 4 , R 5 , L or Ar are each independently selected from one or a combination of two of deuterium, halogen, cyano, aryl groups having 6 to 30 carbon atoms, and heteroaryl groups having 3 to 30 carbon atoms.

[0024] Among them, the aryl groups having 6 to 30 carbon atoms in the substituents of the R 1 , R 2 , R 3 , R 4 , R 5 , L or Ar are selected from phenyl, biphenyl, terphenyl, naphthyl, phenyl-substituted naphthyl, naphthyl-substituted phenyl, anthracenyl, phenanthryl, 9,9'-dimethylfluorenyl, 9,9'-diphenylfluorenyl or spirobifluorenyl.

[0025] Further preferably, L is selected from a single bond, a substituted or unsubstituted phenylene, a substituted or unsubstituted naphthylene, a substituted or unsubstituted biphenylene;

[0026] Ar is selected from any one of the following A-1 to A-12, including but not limited to:

[0027]

[0028] Among them, the structure of the organic electroluminescent compound is selected from any one of the following structures:

[0029]

[0030]

[0031]

[0032]

[0033]

[0034] The present invention also provides a preparation method of the above compound, and the specific synthesis route is as follows:

[0035] When the starting material structure is SM-n-1

[0036]

[0037] The preparation method of compound n is as follows:

[0038]

[0039] When the starting material structure is RM-n-1

[0040]

[0041] The preparation method of compound n is as follows:

[0042]

[0043] Among them, R represents R 1 -R 4 .

[0044] The present invention also provides an organic electroluminescent material, and the material contains the above organic electroluminescent compound.

[0045] The present invention also provides an organic electroluminescent device, and the organic electroluminescent device includes a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode;

[0046] Among them, the above-mentioned organic electroluminescent compound and / or the above-mentioned organic electroluminescent material in the organic layer;

[0047] Preferably, the organic layer includes a light-emitting layer, and the material of the light-emitting layer includes one or a combination of at least two of the above-mentioned organic compounds, or the above-mentioned organic electroluminescent material.

[0048] Preferably, the material of the light-emitting layer includes a host material and a guest material; the host material includes the above-mentioned organic compound.

[0049] Preferably, the organic layer includes an electron transport layer, and the material of the electron transport layer includes one or a combination of at least two of the above-mentioned organic compounds, or the above-mentioned organic electroluminescent material.

[0050] Preferably, the organic layer further includes at least one of a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, or an electron injection layer.

[0051] The present invention also protects the application of the above-mentioned organic electroluminescent compound in the preparation of optical devices;

[0052] Preferably, the optical device includes any one of an organic electroluminescent device, an organic field effect transistor, an organic thin film transistor, an organic light-emitting transistor, an organic integrated circuit, an organic solar cell, an organic field quenching device, a light-emitting electrochemical cell, an organic laser diode, or an organic photoreceptor.

[0053] Specifically, in some embodiments of the present invention, by adding the organic electroluminescent compound provided by the present invention into an OLED light-emitting device, and by studying the driving voltage, current efficiency, and working life of different devices, it is shown that the compound provided by the present invention has the application potential in the preparation of optical devices.

[0054] The term "organic electroluminescent material" in the present disclosure means a material that can be used in an organic electroluminescent device and can include at least one compound. If necessary, the organic electroluminescent material can be included in any layer constituting the organic electroluminescent device. For example, the organic electroluminescent material can be a hole injection material, a hole transport material, a hole auxiliary material, a light-emitting auxiliary material, an electron blocking material, a light-emitting material (including a host material and a dopant material), an electron buffer material, a hole blocking material, an electron transport material, an electron injection material, etc.

[0055] The term "multiple organic electroluminescent materials" in the present disclosure means one or more organic electroluminescent materials that are a combination of at least two compounds, and such materials can be included in any layer constituting the organic electroluminescent device. It can mean both the materials before being included in the organic electroluminescent device (e.g., before vapor deposition) and the materials after being included in the organic electroluminescent device (e.g., after vapor deposition). For example, the multiple organic electroluminescent materials can be a combination of at least two compounds, and such materials can be included in at least one of the following: hole injection layer, hole transport layer, hole auxiliary layer, light emission auxiliary layer, electron blocking layer, light emitting layer, electron buffer layer, hole blocking layer, electron transport layer, and electron injection layer. The at least two compounds can be included in the same layer or different layers, and can be co-evaporated or co-evaporated by mixing, or can be evaporated individually.

[0056] The term "multiple host materials" in the present disclosure means an organic electroluminescent material that is a combination of at least two host materials. It can mean both the materials before being included in the organic electroluminescent device (e.g., before vapor deposition) and the materials after being included in the organic electroluminescent device (e.g., after vapor deposition). The multiple host materials of the present disclosure can be included in any light emitting layer constituting the organic electroluminescent device. Two or more compounds included in the multiple host materials of the present disclosure can be included in one light emitting layer, or can be respectively included in different light emitting layers. For example, when two or more host materials are included in one layer, the layer can be formed by co-evaporation by mixing, or can be formed simultaneously by separate co-evaporation.

[0057] Definition of substituent terms

[0058] As used in the present invention, the term "halogen" can include fluorine, chlorine, bromine, or iodine.

[0059] In the present invention, aryl and arylene include monocyclic, polycyclic, or fused-ring aryl, and the rings can be interrupted by short non-aromatic units and can include a spiro structure, including but not limited to phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, phenylphenanthryl, binaphthyl, phenylnaphthyl, naphthylphenyl, anthryl, indenyl, triphenylene, tetraphenyl, pyrenyl, perylenyl, fluorenyl, phenylfluorenyl, diphenylfluorenyl, benzofluorenyl, spirobifluorenyl, yl, naphthacenyl, fluoranthenyl, etc.

[0060] As used in the present invention, the term "substituted" means that a hydrogen atom in a compound is replaced by another substituent. The position is not limited to a specific position as long as the hydrogen at that position can be replaced by a substituent. And it also includes the replacement of a hydrogen atom by a group formed by the connection of two or more substituents. When there are two or more substituents, the two or more substituents can be the same or different.

[0061] As used in the present invention, unless otherwise specified, a hydrogen atom includes protium, deuterium, and tritium.

[0062] In the present invention, in the definition of a group, a range of the number of carbon atoms is defined, and the number of carbon atoms is any integer within the defined range. For example, C6-C30 aryl represents that the number of carbon atoms of the aryl can be any integer within the range included in 6-30, such as 6, 8, 10, 13, 15, 17, 20, 22, 25, or 30, etc.

[0063] Beneficial effects: By introducing a phenyl group at a specific position, the organic electroluminescent compound of the present invention reduces the molecular ring strain, stabilizes the structure, and further improves the stacking performance, creating favorable conditions for carrier transport, reducing transport resistance and scattering, forming an ordered and dense transport channel, enabling carriers to move and jump more smoothly, thereby obtaining the advantage of high carrier mobility. This advantage is closely related to the driving voltage and current efficiency in the examples. The high carrier mobility reduces the carrier transport resistance, lowers the required driving voltage under the same current requirement, and at the same time allows more carriers to reach the light-emitting layer in time to participate in light emission, reducing losses and improving the current efficiency when the same current is input. Description of the Drawings

[0064] The following further describes the present invention in detail with reference to the drawings and specific embodiments, and the above and / or other advantages of the present invention will become clearer.

[0065] Figure 1 It is a schematic structural diagram of an organic electroluminescent device in an application example of the present invention;

[0066] Among them, 1 is a substrate, 2 is an anode, 3 is a hole injection layer, 4 is a hole transport layer, 5 is a light-emitting layer, 6 is an electron transport layer, 7 is an electron injection layer, and 8 is a cathode;

[0067] Figure 2 It is a 1H NMR spectrum of Compound 23 in an example of the present invention;

[0068] Figure 3 It is a 1H NMR spectrum of Compound 40 in an example of the present invention;

[0069] Figure 4 It is an ultraviolet absorption spectrum of Compound 1 in a toluene solution state in an example of the present invention;

[0070] Figure 5 It is a fluorescence emission spectrum of Compound 1 in a toluene solution state in an example of the present invention. Detailed Description of the Embodiments

[0071] The technical solution 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 on the present invention.

[0072] In the following embodiments, the experimental methods are all conventional methods unless otherwise specified; the reagents and materials can be obtained from commercial channels unless otherwise specified.

[0073] In the following embodiments, both SM-1-1 and SM-40-1 are 1-bromo-8-chlorodibenzofuran;

[0074] In the following embodiments, both SM-1-2 and SM-40-2 are 8-chloro-dibenzofuran-1-boronic acid pinacol ester.

[0075] Example 1:

[0076] The synthesis route of the compound of Formula 1 is as follows:

[0077]

[0078] Synthesis of SM-1-2: In a 500 mL two-necked flask, successively add 1-bromo-8-chlorodibenzofuran (SM-1-1) (20 g, 0.071 mol), bis(pinacolato)diboron (19.84 g, 0.078 mol), potassium acetate (13.9 g, 0.142 mol) and [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) dichloromethane complex (0.58 g, 0.00071 mol). The solvent is 200 mL of 1,4-dioxane. Under nitrogen protection, the reaction is stirred at 110 °C. After a period of time, the reaction solution turns purple-black. The reaction time is 3 h. After the reaction system is cooled, the organic phase obtained by extraction with water and dichloromethane is concentrated under reduced pressure to obtain a solid. The crude product is purified by column chromatography with dichloromethane:petroleum ether = 1:1 to obtain 18.7 g of white solid SM-1-2 (purity 99.98% by HPLC analysis), the yield is 81%, HR-MS (ACPI-M+, m / z): 328.4518. Elemental analysis results: C, 65.79; H, 5.52; B, 3.29; Cl, 10.79; O, 14.61.

[0079] Synthesis of INT-A1-1: In a 500 mL two-necked flask, successively add compound SM-1-2 (10 g, 0.03 mol), 9-bromo-10-phenylanthracene (11.1 g, 0.033 mol), potassium carbonate (0.25 g, 0.002 mol) and [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium dichloromethane complex (0.25 g, 0.0003 mol). The solvent is 100 mL of tetrahydrofuran and 20 mL of water. Under nitrogen protection, the reaction is stirred at 70 °C. After a period of time, the reaction solution turns purple-black. The reaction time is 3 h. After the reaction system is cooled, the organic phase obtained by extraction with water and dichloromethane is concentrated under reduced pressure to obtain a solid. The crude product is purified by column chromatography with dichloromethane:petroleum ether = 1:5 to obtain 11 g of white solid INT-A1-1 (purity 99.96% by HPLC analysis), the yield is 79%, HR-MS (ACPI-M+, m / z): 454.1252. Elemental analysis results: C, 84.48; H, 4.21; Cl, 7.79; O, 3.52.

[0080] Synthesis of SM-1-4: In a 500 mL two-necked flask, successively add 1-chloro-8-bromodibenzofuran (20 g, 0.071 mol), phenylboronic acid (9.6 g, 0.0078 mol), potassium carbonate (19.7 g, 0.14 mol) and [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium dichloromethane complex (0.25 g, 0.0003 mol). The solvent is 100 mL of tetrahydrofuran and 20 mL of water. Under nitrogen protection, the reaction is stirred at 70 °C. After a period of time, the reaction solution turns purple-black. The reaction time is 4 h. After the reaction system is cooled, the organic phase obtained by extraction with water and dichloromethane is concentrated under reduced pressure to obtain a solid. The crude product is purified by column chromatography with dichloromethane:petroleum ether = 1:2 to obtain 16.85 g of white solid SM-1-4 (purity 99.97% by HPLC analysis), the yield is 85%, HR-MS (ACPI-M+, m / z): 278.6396. Elemental analysis results: C, 77.56; H, 3.98; Cl, 12.72; O, 5.74.

[0081] Synthesis of INT-B-1: In a 500 mL two-necked flask, successively add compound SM-1-4 (10 g, 0.04 mol), bis(pinacolato)diboron (18.3 g, 0.07 mol), potassium acetate (10.6 g, 0.1 mol), [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium dichloromethane complex (0.65 g, 0.0008 mol) and 2-bis(cyclohexylphosphino)-2',4',6'-triisopropylbiphenyl (0.57 g, 0.0012 mol). The solvent is 100 mL of 1,4-dioxane. Under nitrogen protection, the reaction is stirred at 110 °C. After a period of time, the reaction solution turns purple-black. The reaction time is 2 h. After the reaction system is cooled, the organic phase obtained by extraction with water and dichloromethane is concentrated under reduced pressure to obtain a solid. The crude product is purified by column chromatography with dichloromethane:petroleum ether = 1:2 to obtain 11.4 g of white solid INT-B-1 (purity 99.97% by HPLC analysis), the yield is 86%, HR-MS (ACPI-M+, m / z): 370.2690. Elemental analysis results: C, 77.86; H, 6.26; B, 2.92; O, 12.96.

[0082] Synthesis of compound 1: In a 500 mL two-necked flask, successively add compound INT-A1-1 (10 g, 0.022 mol), compound INT-B-1 (16.3 g, 0.044 mol), potassium phosphate (6 g, 0.044 mol), bis(4-dimethylaminophenyl)di-tert-butylphosphine dichloropalladium(II) (0.155 g, 0.0008 mol) and tetrabutylammonium bromide (0.57 g, 0.002 mol). The solvent is 100 mL of toluene and 20 mL of water. Under nitrogen protection, the reaction is stirred at 90 °C. After a period of time, the reaction solution turns purple-black. The reaction time is 2 h. After the reaction system is cooled, the organic phase obtained by extraction with water and dichloromethane is concentrated under reduced pressure to obtain a solid. The crude product is purified by column chromatography with dichloromethane:petroleum ether = 1:1 to obtain 11.4 g of off-white solid 1 (purity 99.97% by HPLC analysis), the yield is 82%, HR-MS (ACPI-M+, m / z): 662.8373. Elemental analysis results: C, 90.61; H, 4.56; O, 4.83.

[0083] Figure 4 is the ultraviolet absorption spectrum of compound 1 in toluene solution state. It can be seen from the figure that at 10 -5In the toluene solution state, in the range of 300 - 450 nm, the main absorption peak of the material is at 330 nm, and there is a shoulder peak at 380 nm, corresponding to the π-π* transition related to the anthracene skeleton. The presence of the anthracene moiety can promote the triplet-triplet upconversion process in the presence of the lowest triplet state. The dibenzofuran moiety has high thermal stability, light extraction efficiency, and good charge transport properties. At the same time, its high triplet energy level leads to an increase in the T2 state.

[0084] Figure 5 It is the fluorescence emission spectrum of Compound 1 in the toluene solution state. As can be seen from the figure: fine structure emission is exhibited in the toluene solution, and the emission peaks are 423 nm and 437 nm respectively. This indicates that Compound 1 has obvious local excitation properties because the spatial structure of Compound 1 is distorted, resulting in weaker charge transfer (CT) properties of the molecule. These photophysical properties indicate that the compound has potential application prospects for the preparation of blue light non-doped OLED devices.

[0085] Example 2:

[0086] The synthetic route of Compound 23 is as follows:

[0087]

[0088] Synthesis of RM-23-2: In a 500 mL two-necked flask, successively add Compound 1-bromo-8-hydroxy dibenzofuran (RM-23-1) (30 g, 0.081 mol) and 300 mL of dichloromethane. Under nitrogen protection, stir the reaction at room temperature, add pyridine (18 g, 0.45 mol) and stir for 20 minutes under a nitrogen atmosphere. Cool the reaction solution to 0 °C, and dropwise add trifluoromethanesulfonic acid (41 g, 0.21 mol) under a nitrogen atmosphere. The reaction time is 3 h. After the reaction system is cooled, extract with water and dichloromethane, and concentrate the obtained organic phase under reduced pressure to obtain a solid. Purify the crude product by column chromatography with dichloromethane: petroleum ether = 1:50 to obtain 18.7 g of white solid RM-23-2 (HPLC analysis purity 99.98%), with a yield of 61%. HR-MS (ACPI-M+, m / z): 395.1318. Elemental analysis results: C, 39.52; H, 1.53; Br, 20.22; F, 14.42; O, 16.20; S, 8.11.

[0089] Synthesis of RM-23-3: The same synthesis procedure as that of SM-1-2 in Example 1, except that compound RM-23-2 was used to replace SM-1-1, to obtain 14.6 g of RM-23-3 (purity 99.88% by HPLC analysis), with a yield of 81%, HR-MS (ACPI-M+, m / z): 328.6423. Elemental analysis results: C, 65.79; H, 5.52; B, 3.29; Cl, 10.79; O, 14.61.

[0090] Synthesis of INT-A2-23: In a 500 mL two-necked flask, compound RM-23-3 (20 g, 0.075 mol) and 9-bromo-10-(1-naphthyl)anthracene (15 g, 0.65 mol) were successively added and stirred for 20 minutes. Then potassium carbonate (0.26 g, 0.002 mol) and [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium dichloromethane complex (0.24 g, 0.0004 mol) were added. The solvent was 100 mL of tetrahydrofuran and 20 mL of water. The reaction was stirred at 70 °C under nitrogen protection. After a period of time, the reaction solution turned purple-black, and the reaction time was 3 h. After the reaction system was cooled, the organic phase obtained by extraction with water and dichloromethane was concentrated under reduced pressure to obtain a solid. The crude product was purified by column chromatography with dichloromethane:petroleum ether = 1:10 to obtain 17 g of INT-A2-23 (purity 99.89% by HPLC analysis), with a yield of 75%, HR-MS (ACPI-M+, m / z): 454.7225. Elemental analysis results: C, 84.48; H, 4.21; Cl, 7.79; O, 3.52.

[0091] Synthesis of SM-23-4: The same synthesis procedure as that of SM-1-4 in Example 1, except that 1-bromo-7-chlorodibenzofuran was used to replace 1-chloro-8-bromodibenzofuran, to obtain 23 g of SM-23-4 (purity 99.78% by HPLC analysis), with a yield of 84%, HR-MS (ACPI-M+, m / z): 278.0458. Elemental analysis results: C, 77.56; H, 3.98; Cl, 12.72; O, 5.74.

[0092] Synthesis of INT-B-23: The same synthesis procedure as that of INT-B-1 in Example 1, except that compound RM-23-4 was used to replace SM-1-4, to obtain 15 g of INT-B-23 (purity 99.89% by HPLC analysis), with a yield of 75%, HR-MS (ACPI-M+, m / z): 370.0253. Elemental analysis results: C, 77.86; H, 6.26; B, 2.92; O, 12.96.

[0093] Synthesis of Compound 23: In a 500 mL two-necked flask, successively add Compound INT-A2-23 (10 g, 0.032 mol), Compound INT-B-23 (16 g, 0.054 mol), potassium phosphate (5.6 g, 0.034 mol), bis(4-dimethylaminophenyl)di-tert-butylphosphine palladium(II) dichloride (0.145 g, 0.0006 mol), and tetrabutylammonium bromide (0.67 g, 0.002 mol). The solvent is 100 mL of toluene and 20 mL of water. Under nitrogen protection, stir the reaction at 90 °C. After a period of time, the reaction solution turns purple-black. The reaction time is 2 h. After the reaction system cools down, extract with water and dichloromethane. The obtained organic phase is concentrated under reduced pressure to obtain a solid. The crude product is purified by column chromatography with dichloromethane:petroleum ether = 1:20 to obtain 13 g of Compound 23, (purity by HPLC analysis: 99.92%), with a yield of 65%. HR-MS (ACPI-M+, m / z): 712.8520. Elemental analysis results: C, 90.99; H, 4.52; O, 4.49.

[0094] Example 3:

[0095] The synthetic route of Compound 40 is shown as follows:

[0096]

[0097] Synthesis of Intermediate SM-40-2: The same as the synthesis of Intermediate SM-1-2, to obtain 14 g of Intermediate SM-40-2, (purity by HPLC analysis: 99.89%), with a yield of 85%.

[0098] Synthesis of INT-A1-40: In a 500 mL two-necked flask, successively add Compound SM-40-2 (10 g, 0.04 mol), 99-bromo-10-(9,9-dimethyl-9H-fluoren-2-yl)anthracene (13 g, 0.043 mol), potassium carbonate (0.3 g, 0.004 mol), and [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride dichloromethane complex (0.27 g, 0.0002 mol). The solvent is 100 mL of tetrahydrofuran and 20 mL of water. Under nitrogen protection, stir the reaction at 70 °C. After a period of time, the reaction solution turns purple-black. The reaction time is 3 h. After the reaction system cools down, extract with water and dichloromethane. The obtained organic phase is concentrated under reduced pressure to obtain a solid. The crude product is purified by column chromatography with dichloromethane:petroleum ether = 1:15 to obtain 15 g of INT-A1-40, (purity by HPLC analysis: 99.92%), with a yield of 77%. HR-MS (ACPI-M+, m / z): 570.2541. Elemental analysis results: C, 86.23; H, 4.77; Cl, 6.21; O, 2.80.

[0099] Synthesis of SM-40-4: The synthesis procedure was the same as that of SM-1-4 in Example 1, except that 6-bromo-2-chlorobenzofuran was used instead of 1-chloro-8-bromodibenzofuran, and 20 g of SM-40-4 was obtained (purity 99.89% by HPLC analysis), with a yield of 86%.

[0100] Synthesis of INT-B-40: The synthesis procedure was the same as that of INT-B-1 in Example 1, except that compound SM-40-4 was used instead of SM-1-4, and 12 g of INT-B-40 was obtained, with a yield of 76%.

[0101] Synthesis of Compound 40: In a 500 mL two-necked flask, compound INT-A1-40 (10 g, 0.045 mol) and compound INT-B-40 (15 g, 0.042 mol) were added successively. Potassium phosphate (5.3 g, 0.036 mol), bis(4-dimethylaminophenyl)di-tert-butylphosphine palladium(II) dichloride (0.135 g, 0.0006 mol), and tetrabutylammonium bromide (0.7 g, 0.002 mol) were added. The solvent was 100 mL of toluene and 20 mL of water. The reaction was stirred at 90 °C under nitrogen protection. After a period of time, the reaction solution turned purple-black, and the reaction time was 2 h. After the reaction system was cooled, the organic phase obtained by extraction with water and dichloromethane was concentrated under reduced pressure to obtain a solid. The crude product was purified by column chromatography with dichloromethane:petroleum ether = 1:30 to obtain 23 g of compound 40 (purity 99.82% by HPLC analysis), with a yield of 63%. HR-MS (ACPI-M+, m / z): 778.3220. Elemental analysis results: C, 90.97; H, 4.92; O, 4.11.

[0102] Example 4:

[0103]

[0104] Synthesis of Intermediate SM-55-2: The synthesis was the same as that of Intermediate SM-1-2, and 16 g of Intermediate SM-55-2 was obtained (purity 99.89% by HPLC analysis), with a yield of 86%.

[0105] Synthesis of INT-A-55: In a 500 mL two-necked flask, successively add compound SM-55-2 (11 g, 0.035 mol), potassium carbonate (0.5 g, 0.005 mol) and [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium dichloromethane complex (0.25 g, 0.00025 mol). The solvent is 100 mL of tetrahydrofuran and 20 mL of water. Under nitrogen protection, the reaction is stirred at 70 °C. After a period of time, the reaction solution turns purple-black. The reaction time is 3 h. After the reaction system cools down, the organic phase obtained by extraction with water and dichloromethane is concentrated under reduced pressure to obtain a solid. The crude product is purified by column chromatography with dichloromethane:petroleum ether = 1:20 to obtain 15 g of INT-A1-55, (purity analyzed by HPLC is 99.92%), the yield is 70%, HR-MS (ACPI-M+, m / z): 619.3541. Elemental analysis results: C, 85.22; H, 4.23; Cl, 5.72; N, 2.26; O, 2.58.

[0106] Synthesis of SM-55-4: Follow the synthesis steps of SM-1-4 in Example 1, with the difference that 2-bromo-8-chlorobenzofuran is used instead of 1-chloro-8-bromodibenzofuran to obtain 22 g of SM-55-4, (purity analyzed by HPLC is 99.89%), and the yield is 80%.

[0107] Synthesis of INT-B-55: Follow the synthesis steps of INT-B-1 in Example 1, with the difference that compound SM-55-4 is used instead of SM-1-4 to obtain 15 g of INT-B-55, and the yield is 66%.

[0108] Synthesis of compound 55: Follow the synthesis steps of compound 1 in Example 1, with the difference that compound INT-A-55 is used instead of INT-A1-1, and compound INT-B-55 is used instead of INT-B-1 to obtain 20 g of compound 55, (purity analyzed by HPLC is 99.82%), the yield is 63%, HR-MS (ACPI-M+, m / z): 903.3320. Elemental analysis results: C, 90.34; H, 4.57; N, 1.55; O, 3.54.

[0109] Example 5:

[0110]

[0111] Synthesis of intermediate SM-67-2: Follow the synthesis of intermediate SM-1-2 to obtain 17 g of intermediate SM-67-2, (purity analyzed by HPLC is 99.89%), and the yield is 76%.

[0112] Synthesis of INT-A-67: In a 500 mL two-necked flask, successively add compound SM-67-2 (16 g, 0.075 mol), potassium carbonate (0.5 g, 0.005 mol) and [1,1'-bis(diphenylphosphino)ferrocene] palladium dichloride dichloromethane complex (0.55 g, 0.00026 mol). The solvent is 100 mL of tetrahydrofuran and 20 mL of water. Under nitrogen protection, the reaction is stirred at 70 °C. After a period of time, the reaction solution turns purple-black. The reaction time is 3 h. After the reaction system cools down, the organic phase obtained by extraction with water and dichloromethane is concentrated under reduced pressure to obtain a solid. The crude product is purified by column chromatography with dichloromethane:petroleum ether = 1:20 to obtain 15 g of INT-A-67 (purity 99.92% by HPLC analysis), with a yield of 70%. HR-MS (ACPI-M+, m / z): 680.235. Elemental analysis results: C, 88.16; H, 4.29; Cl, 5.20; O, 2.35.

[0113] Synthesis of SM-67-4: The same synthesis steps as those of SM-1-4 in Example 1, except that 2-bromo-9-chlorobenzofuran is used instead of 1-chloro-8-bromodibenzofuran, to obtain 25 g of SM-67-4 (purity 99.89% by HPLC analysis), with a yield of 81%.

[0114] Synthesis of INT-B-67: The same synthesis steps as those of INT-B-1 in Example 1, except that compound SM-67-4 is used instead of SM-1-4, to obtain 16 g of INT-B-67, with a yield of 62%.

[0115] Synthesis of compound 67: The same synthesis steps as those of compound 1 in Example 1, except that compound INT-A-67 is used instead of INT-A1-1, and compound INT-B-67 is used instead of INT-B-1, to obtain 12 g of compound 67 (purity 99.82% by HPLC analysis), with a yield of 62%. HR-MS (ACPI-M+, m / z): 950.3470. Elemental analysis results: C, 92.18; H, 4.45; O, 3.36.

[0116] Prepare the compounds of Examples 6 to 16 according to the synthesis steps of Examples 1 to 5. The specific steps are as follows:

[0117] Use raw material A instead of 9-bromo-10-phenylanthracene to prepare the corresponding INT-A-n. The synthesis of INT-A-n is shown in Table 1:

[0118] Table 1

[0119]

[0120]

[0121]

[0122]

[0123] Use raw material B to replace 1-chloro-8-bromodibenzofuran and raw material C to replace phenylboronic acid to prepare the corresponding INT-B-n. The synthesis of INT-B-n is shown in Table 2:

[0124] Table 2

[0125]

[0126]

[0127]

[0128]

[0129] Among them, the HPLC analysis purity of SM-9-4 in Example 6 is 99.87%, the yield is 75%, and HR-MS (ACPI-M+, m / z): 378.6396. Elemental analysis results: C, 82.43; H, 3.99; Cl, 9.36; O, 4.22.

[0130] The HPLC analysis purity of SM-14-4 in Example 7 is 99.87%, the yield is 85%, and HR-MS (ACPI-M+, m / z): 330.1732. Elemental analysis results: C, 79.88; H, 4.57; Cl, 10.72; O, 4.84.

[0131] Synthesis of SM-105-4 in Example 8: The same as the synthesis of SM-14-4, the yield is 85%, and HR-MS (ACPI-M+, m / z): 330.2514. Elemental analysis results: C, 79.88; H, 4.57; Cl, 10.72; O, 4.84.

[0132] Synthesis of SM-120-4 in Example 10: The same as the synthesis of SM-14-4, the yield is 75%, and HR-MS (ACPI-M+, m / z): 330.2628. Elemental analysis results: C, 79.88; H, 4.57; Cl, 10.72; O, 4.84.

[0133] The HPLC analysis purity of SM-149-4 in Example 15 is 99.87%, the yield is 77%, and HR-MS (ACPI-M+, m / z): 432.1732. Elemental analysis results: C, 83.23; H, 4.89; Cl, 8.19; O, 3.70.

[0134] Synthesis of SM-150-4 in Example 16: Following the same synthesis steps as SM-149-4, with a yield of 75%, HR-MS (ACPI-M+, m / z): 356.1376. Results of elemental analysis: C, 80.78; H, 4.80; Cl, 9.93; O, 4.48.

[0135] Using INT-A-n to replace INT-A1-1 and INT-B-n to replace INT-B-1 to prepare the corresponding compound X, the synthesis of compound X is shown in Table 3 as follows:

[0136] Table 3

[0137]

[0138]

[0139]

[0140]

[0141] The characterization data of the compound X prepared in Examples 6 to 16 are shown in Table 4 as follows:

[0142] Table 4

[0143]

[0144]

[0145] Application Example: Preparation and Performance Evaluation of Organic Electroluminescent Devices

[0146] Application Examples 1 to 17 and Comparative Application Examples 1 to 2 respectively provide different OLED light-emitting devices, and their structural schematic diagrams are as Figure 1 shown, specifically including the following structures: substrate 1 (glass substrate), anode 2 (indium tin oxide coated ITO), hole injection layer 3 (HIL), hole transport layer 4 (HTL), light-emitting layer 5 (EML), electron transport layer 6 (ETL), electron injection layer 7 (EIL), and cathode 8.

[0147] The specific preparation steps of the above organic electroluminescent device are as follows:

[0148] (1) Substrate cleaning: The glass substrate coated with transparent ITO is ultrasonically treated in an aqueous cleaning agent (the composition and concentration of the aqueous cleaning agent: ethylene glycol solvent ≤ 10 wt%, triethanolamine ≤ 1 wt%), rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone:ethanol (volume ratio 1:1), baked in a clean environment until all moisture is removed, and then cleaned with ultraviolet light and ozone;

[0149] (2) Evaporation deposition of the organic light-emitting functional layer:

[0150] Place the glass substrate with the anode layer in a vacuum chamber, evacuate to 1×10 -6 to 2×10 -4 Pa, and vacuum-evaporate a mixture of HATCN and HT on the anode layer film as the hole injection layer, with an evaporation thickness of 10 nm;

[0151] Evaporate a hole transport layer (material: HT) on the hole injection layer, with an evaporation film thickness of 80 nm;

[0152] Evaporate a light-emitting layer on the hole transport layer. The specific preparation method is: vacuum-evaporate a mixture of the light-emitting host material (the materials are shown in Table 5) and the guest material (piq)2Ir(acac) in a co-evaporation manner, with a total evaporation film thickness of 30 nm;

[0153] Evaporate an electron transport layer on the light-emitting layer. The specific preparation method is: vacuum-evaporate the corresponding materials (the materials are shown in Table 5) in a co-evaporation manner, with a total evaporation film thickness of 30 nm;

[0154] Vacuum-evaporate an electron injection layer (material: LiQ) on the electron transport layer, with a total evaporation film thickness of 1 nm;

[0155] Evaporate Al as the cathode on the electron injection layer, with a total evaporation film thickness of 90 nm.

[0156] Table 5

[0157]

[0158]

[0159]

[0160] Among them, the above materials are specifically:

[0161]

[0162] Compounds 4, 14, 23, 34, 45, 51, 75, 93, 103, and 134 used in the above Table 5 are all prepared according to the preparation methods of Examples 1 to 16.

[0163] Performance test:

[0164] Instrument: The characteristics such as current, voltage, brightness, and emission spectrum of the device are synchronously tested using a PR 650 spectral scanning luminance meter and a Keithley K 2400 digital source meter system;

[0165] Optoelectronic property test conditions: The current density is 10 mA / cm 2 .

[0166] Lifetime test: The current density is 30 mA / cm 2 , and record the time (in hours) when the device brightness drops to 95% of the original brightness.

[0167] The test results of the device performance are shown in Table 6 as follows:

[0168] Table 6

[0169]

[0170] It can be seen from the data in Table 6 that the lowest driving voltage in the application examples can be as low as 3.33 V. Compared with the comparative application examples, the driving voltage of most application examples is below 3.91 V or even below 3.54 V. This means that less electrical energy is consumed during use, which can effectively reduce energy consumption, save costs, and at the same time reduce problems such as heat generation, which is beneficial to the long-term stable operation of the device. The highest current efficiency can reach 33.52 Cd / A, and multiple application examples can reach above 18 Cd / A. This indicates that under the same current input, the device can emit brighter light, with higher luminous efficiency, and can achieve better luminous effects with less power consumption, improving the energy utilization efficiency. The longest lifetime can reach 326.3 hours, and the lifetime of most application examples is above 180 h, or even above 289 h. This shows that the device has strong durability and does not need to be replaced frequently, which not only reduces the maintenance cost, but also improves the convenience and stability of use, and has high reliability in practical applications.

[0171] The present invention provides an idea for an organic electroluminescent compound, its preparation method and application. There are many methods and ways to specifically implement this technical solution. The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention. Each component not clearly defined in this embodiment can be implemented by existing technologies.

Claims

1. An organic electroluminescent compound, characterized in that: The structure of the organic electroluminescent compound is shown in Formula 1: Among them, R 1 -R 4 Each is independently selected from hydrogen, deuterium, halogen, cyano, substituted or unsubstituted aryl having 6 to 60 carbon atoms, and substituted or unsubstituted heteroaryl having 5 to 60 carbon atoms; R 5 With R 1 -R 4 Any one of them is different, specifically, R 5 Selected from formula 1-R 5 The structure shown: L is selected from a single bond, a substituted or unsubstituted arylene group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroarylene group having 3 to 30 carbon atoms; Ar is selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms; R 6 To R 8 Each is independently hydrogen, deuterium, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted heterocyclic group having 3 to 30 carbon atoms; Among them, r 6 is an integer from 0 to 7, r 7 and r 8 Each is an integer from 0 to 8; when r 6 To r 8 When each is 2, R 6 and R 8 The same as or different from each other.

2. The organic electroluminescent compound according to claim 1, characterized in that R 1 -R 4 At least one of them is selected from substituted or unsubstituted aryl having 6 to 30 carbon atoms and substituted or unsubstituted heteroaryl having 3 to 30 carbon atoms, in which case R 1 -R 4 The other positions in the are hydrogen.

3. The organic electroluminescent compound according to claim 1, characterized in that L is selected from a single bond, a substituted or unsubstituted arylene group having 6-25 carbon atoms, or a substituted or unsubstituted heteroarylene group having 3-25 carbon atoms; Ar is selected from a substituted or unsubstituted aryl group having 6-25 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3-25 carbon atoms.

4. The organic electroluminescent compound according to any one of claims 1 to 3, characterized in that The R 1 , R 2 , R 3 , R 4 , R 5 The substituents of L or Ar are independently selected from one or a combination of two of deuterium, halogen, cyano, aryl having 6-30 carbon atoms, and heteroaryl having 3-30 carbon atoms.

5. The organic electroluminescent compound according to claim 4, characterized in that: Ar is selected from a substituted or unsubstituted aryl group having 6 to 20 carbon atoms and a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms.

6. The organic electroluminescent compound according to claim 4, characterized in that: The R 1 , R 2 , R 3 , R 4 , R 5 The aromatic group having 6-30 carbon atoms in the substituent of L or Ar is selected from phenyl, biphenyl, terphenyl, naphthyl, phenyl-substituted naphthyl, naphthyl-substituted phenyl, anthracenyl, phenanthryl, 9,9'-dimethylfluorenyl, 9,9'-diphenylfluorenyl or spirobifluorenyl.

7. The organic electroluminescent compound according to claim 1, characterized in that The structure of the organic electroluminescent compound is selected from any one of the following structures:

8. An organic electroluminescent material, characterized in that: The material contains the organic electroluminescent compound according to claim 1.

9. An organic electroluminescent device, characterized in that: The organic electroluminescent device comprises a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode; Wherein, the organic layer comprises the organic electroluminescent compound described in claim 1 and / or the organic electroluminescent material described in claim 8.

10. Use of the organic electroluminescent compound according to claim 1 in preparing optical devices.

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