A host material, a preparation method thereof, a dual-host organic electroluminescent material containing the same, and an organic electroluminescent device

Abstract

The present invention belongs to the field of organic electroluminescent materials, and discloses a host material, a preparation method, an organic electroluminescent material containing the same, and an organic electroluminescent device. The structure of the host material is shown in Chemical Formula I:. After being used in an organic electroluminescent device, the host material provided by the present invention can not only prolong the life of the device, but also reduce the driving voltage and improve the luminous efficiency of the device.

Description

Technical Field

[0001] The present invention belongs to the field of organic electroluminescent materials, and particularly relates to a host material, a preparation method, a dual-host organic electroluminescent material containing the same, and an organic electroluminescent device. Background Art

[0002] Organic electroluminescent displays (OLEDs) are active light-emitting display devices. Currently, small and medium-sized OLED displays have been widely used in high-end smartphones produced by companies such as Huawei, Xiaomi, and Samsung. Obtaining the best luminous efficiency of the device under low operating voltage conditions is a common requirement in the OLED field.

[0003] OLED luminescence is divided into two ways: fluorescence luminescence and phosphorescence luminescence. The luminescent materials of OLEDs have gradually become the key materials affecting the display effect and service life of OLEDs due to their fast attenuation rate. Deuterium is non-toxic, non-radioactive, and safe for the human body. More importantly, the C-D bond is more stable (6-9 times) than the C-H bond. When deuterium atoms are introduced into the material, the spin-orbit coupling effect of the luminescent molecules will be enhanced, which is conducive to the generation of phosphorescence. After introducing deuterium atoms, due to the shorter bond length and larger bond energy of the carbon-deuterium bond, the energy of the luminescent material will decrease. The influence on the luminous efficiency and driving voltage of the light-emitting device depends on the action of various factors, and the result obtained is unpredictable.

[0004] Currently, it is known that deuteration of OLED materials can improve the service life of OLED devices. However, how to improve the driving voltage and luminous efficiency of the device through deuteration is a technical problem that urgently needs to be solved at present. Summary of the Invention

[0005] In view of this, aiming at the deficiencies of the prior art, the present invention discloses and provides a host material, a preparation method, a dual-host organic electroluminescent material containing the same, and an organic electroluminescent device.

[0006] It should be noted that the host material disclosed in the present invention has D substituted at the 5, 6, 11, and 12 positions on chrysene. The deuteration position makes the compound structure more symmetrical, adjusts the molecular spacing and bond energy of the obtained compound, and helps to improve the luminous efficiency and reduce the driving voltage.

[0007] In order to achieve the above object, the first object of the present invention is to provide a host material. The following technical scheme is adopted:

[0008] A host material, the structure of the host material is shown in Chemical Formula I:

[0009] ;

[0010] Wherein,

[0011] Ar1 is selected from the following groups which may or may not be deuterium-substituted:

[0012] phenyl, naphthyl, biphenyl, terphenyl, phenylnaphthyl, methylphenyl, dimethylfluorenyl.

[0013] Furthermore, the structure of the host material is specifically as follows:

[0014] .

[0015] In the above technical solution, the host material is selected from any one of the following compounds:

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024] .

[0025] The second object of the present invention is to provide a preparation method of the host material as described above.

[0026] The compounds of the present invention can be prepared by synthetic methods known to those skilled in the art, or preferably prepared by the following reaction process.

[0027] ;

[0028] In the above formula, Ar1 is defined as in Chemical Formula I above, and Hal is selected from Cl, Br.

[0029] Specifically, the preparation method is as follows:

[0030] (1)Reactant I-a (1.0 eq), silver carbonate (0.1 - 0.3 eq), cyclohexyldiphenylphosphine (0.5 - 1.0 eq), potassium carbonate (1.0 - 1.4 eq), deuterium water (T2O) (20 - 30 eq) and toluene were stirred at 100 - 120 °C for 7 - 10 hours, then cooled to room temperature. A saturated ammonium chloride aqueous solution was added to terminate the reaction. Water and dichloromethane were added, and the layers were separated. The organic layer was dried over Na2SO4, filtered, and the filtrate was concentrated. Isopropanol was added, and the resulting solid was subjected to column chromatography to obtain intermediate I-b;

[0031] (2)I-b (1.0 eq), reactant I-c (1.0 - 1.5 eq), and potassium acetate (2.0 - 2.5 eq) were added to a reactor and purged with nitrogen three times. 1,4-dioxane was added as a solvent and purged with nitrogen three times. Then Pd2(dba)3 (0.01 - 0.05 eq) and X-phos (0.05 - 1.2 eq) were added and purged with nitrogen three times. The mixture was heated to reflux under nitrogen protection for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediate I-d;

[0032] (3)Intermediate I-d (1.0 eq), reactant I-e (1 - 1.3 eq), and K2CO3 (2 - 4 eq) were added to a reactor and purged with nitrogen three times. A mixture of H2O and THF was added as a solvent and purged with nitrogen three times. Then Pd(Ph3)4 (0.01 - 0.05 eq) was added and purged with nitrogen three times. The mixture was heated to reflux under nitrogen protection for 12 hours. After the reaction was completed, the mixture was cooled to room temperature. Subsequently, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediate I-f;

[0033] (4)Intermediate I-f (1.0 eq), (methoxymethyl)triphenylphosphonium chloride (1.0 - 1.5 eq) and THF were added to a reaction vessel and stirred for 10 minutes. A potassium tert-butoxide solution was slowly added dropwise at 0 °C, and then the temperature was slowly raised. After stirring at room temperature for 3 - 5 hours, distilled water was added. The organic layer was extracted with ethyl acetate and the organic phase was dried over sodium sulfate without further purification. Boron trifluoride anisole and dichloromethane were added to the reaction vessel and stirred for 3 hours. After the reaction was completed, the organic layer was extracted with dichloromethane and water, and then the extracted organic layer was dried over sodium sulfate. The solvent was removed using a rotary evaporator. Thereafter, it was purified by column chromatography to obtain intermediate I-g;

[0034] (5)Under N2 protection, intermediate I-g (1.0 eq), reactant I-h (1 - 1.3 eq), PdCl2(dppf) (0.1 - 0.2 eq) and potassium acetate (2.0 - 3.0 eq) were dissolved in DMF, heated to 80 - 90 °C, and reacted for 10 - 12 h. The solvent was removed using a rotary evaporator. The residue was added to dichloromethane, stirred, filtered, and the remaining material was purified by column chromatography to obtain intermediate I-i;

[0035] (6)Under N2 protection, intermediate I-i (1.0 eq), reactant I-j (1 - 1.2 eq), palladium acetate (Pd(OAc)2) (0.05 - 0.15 eq), and 2-cyclohexyl-2,4,6-triisopropylbiphenyl (X-Phos) (0.01 - 0.3 eq), cesium carbonate (Cs2CO3) (2.0 - 2.5 eq) were separately added to a mixed solvent of toluene, ethanol, and water (4:1:1). The temperature was raised to 80 - 95 °C, and the reaction was carried out for 10 - 12 h. The solvent was removed using a rotary evaporator, and the remaining material was purified by column chromatography. The filtrate was concentrated using a rotary evaporator to obtain compound I.

[0036] It should be noted that for a series of palladium-catalyzed coupling reactions in the present invention, on the one hand, the difference in activity I > Br > Cl is utilized, and on the other hand, the reaction sites are controlled by controlling the reaction conditions. The reaction is purified by column chromatography or through a silica gel funnel to remove by-products and obtain the target compound.

[0037] Refer to the common general knowledge as follows:

[0038] "Organotransition Metal Chemistry" (Original Sixth Edition), Robert H. Crabtree, Publisher: East China University of Science and Technology Press, Shanghai, Publication Date: 2017 - 09 - 00, ISBN: 978 - 7 - 5628 - 5111 - 0, page 388.

[0039] "Experimental Course of Organic Chemistry and Optoelectronic Materials", Chen Runfeng, Publisher: Southeast University Press, Publication Date: 2019 - 11 - 00, ISBN: 9787564184230, page 174.

[0040] For raw materials that are not disclosed, those skilled in the art can synthesize them using classical Suzuki coupling reactions, Buchwald–Hartwig coupling reactions, and butyllithium reactions and apply them to the present invention.

[0041] In addition, the substitution positions of chrysene in the present invention are defined as follows:

[0042] .

[0043] The third object of the present invention is to provide a dual-host organic electroluminescent material, which includes a first host material and a second host material. The first host material is the host material as described above and has the structure shown in Formula I; the second host material has the structure shown in Formula II:

[0044] ;

[0045] wherein, f and n are independently selected from 0 or 1, and f + n = 1;

[0046] Ar1 and Ar2 are independently selected from the following groups:

[0047] ;

[0048] Ar3 - Ar6 are independently selected from hydrogen, and the following substituted or unsubstituted groups:

[0049] phenyl, naphthalene, anthracene, phenanthrene, biphenyl, terphenyl, quaterphenyl, dimethylfluorene, diphenylfluorene, pyridine, dibenzofuran, dibenzothiophene, 9-phenyl-carbazole, quinoline, benzonaphthofuran, benzonaphthothiophene, quinoxaline, quinazoline, and the following group:

[0050] ;

[0051] When substituted, the substituent is selected from D, F or phenyl;

[0052] When substituted with phenyl, the phenyl can be fused with adjacent groups to form a ring.

[0053] In the technical solution of the present invention, the second host material can be specifically exemplified by the following compounds, but not limited thereto:

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066] 。

[0067] The fourth object of the present invention is to provide an organic electroluminescent device, which comprises the host material or the dual-host organic electroluminescent material described above.

[0068] Specifically, the organic electroluminescent device includes a first electrode, a second electrode, and at least one organic electroluminescent material layer disposed between the first electrode and the second electrode; the organic electroluminescent material layer contains the dual-host organic electroluminescent material as described above.

[0069] Moreover, the dual-host organic electroluminescent material serves as the host material of the light-emitting layer of the organic electroluminescent device.

[0070] Furthermore, the first host material has the structure shown in Formula I, the second host material has the structure shown in Formula II, the mass ratio of the first host material to the second host material is (1~10):(10~1), and the mass ratio of the dual-host organic electroluminescent material to the doping material is (1~99):(99~1).

[0071] In the present invention, the organic electroluminescent device includes an anode, a hole transport region, a light-emitting layer, an electron transport region, and a cathode.

[0072] The anode material preferably has a material with a large work function to enable holes to be smoothly injected into the organic material layer. The anode materials include: metals such as vanadium, chromium, copper, zinc, and gold, or their alloys; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); combinations of metals and oxides such as ZnO:Al or SnO2:Sb; conductive polymers such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDOT), polypyrrole, and polyaniline, but not limited thereto.

[0073] The cathode material preferably has a material with a small work function to enable electrons to be smoothly injected into the organic material layer. The cathode materials include: metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or their alloys; multi-layer structure materials such as LiF / Al or LiO2 / Al; but not limited thereto.

[0074] The hole transport region includes a hole injection layer, a hole transport layer, an electron blocking layer, and a hole blocking layer, and the light-emitting layer is located between the electron blocking layer and the hole blocking layer.

[0075] Among them, the hole injection layer material is a hole material that receives holes from the anode at a low voltage. The highest occupied molecular orbital (HOMO) of the hole injection material is preferably between the work function of the anode material and the HOMO of the surrounding organic material layer. The hole injection materials include metal porphyrins, oligothiophenes, arylamine-based organic materials, hexanitrile hexazatriphenylene-based organic materials, quinacridone-based organic materials, perylene-based organic materials, anthraquinone, and conductive polymers based on polyaniline and polythiophene.

[0076] The hole transport layer material is a material that can receive holes from the anode or the hole injection layer, transport the holes to the light-emitting layer, and has a high hole mobility. The hole transport layer materials include arylamine-based organic materials, conductive polymers, block copolymers having both a conjugated part and a non-conjugated part, but are not limited thereto.

[0077] The electron blocking layer is disposed between the hole transport layer and the light-emitting layer, and the electron blocking layer material includes arylamine-based organic materials.

[0078] The hole blocking layer is disposed between the hole transport layer and the light-emitting layer, and the hole blocking layer material includes triazine-based compounds.

[0079] The electron transport region includes an electron transport layer and an electron injection layer.

[0080] The electron transport layer has the function of promoting electron transport. The electron transport material is a material that receives electrons from the cathode and transports the electrons to the light-emitting layer, and has a high electron mobility. The electron transport materials include Al complexes of 8-hydroxyquinoline, complexes of Alq3, organic radical compounds, hydroxyflavone-metal complexes, but are not limited thereto. The thickness of the electron transport layer is 1 nm to 50 nm, which can prevent the decline of electron transport characteristics and prevent the increase of driving voltage.

[0081] The electron injection layer has the function of promoting electron injection. The electron injection material is a material having the ability to transport electrons, having an excellent electron injection effect on the light-emitting layer or the light-emitting material, preventing the excitons generated in the light-emitting layer from migrating to the hole injection layer, and having an excellent thin film forming ability. The electron injection layer materials include fluorenone, anthraquinone dimethane, biphenylquinone, thiopyran dioxide, oxazole, dioxazole, triazole, imidazole, perylene tetracarboxylic acid, subfluorene methane, anthrone, etc. and their derivatives, metal complexes, nitrogen-containing five-membered ring derivatives, but are not limited thereto.

[0082] In the present invention, the organic electroluminescent device can be a top-emitting type, a bottom-emitting type, or a double-sided emitting type.

[0083] The device described in the present invention can be used in organic light-emitting devices, including but not limited to flat panel displays, computer monitors, a medical monitor, a television, billboards, a lamp for internal or external lighting and / or signaling, a head-up display, a fully transparent or partially transparent display, a flexible display, a laser printer, a telephone, a mobile phone, a tablet, an album, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a video camera, a viewfinder, a microdisplay, a three-dimensional display, a virtual reality or augmented reality display, a vehicle, a video wall including a plurality of displays tiled together, a theater or venue screen, a light therapy device, and a sign.

[0084] Compared with the prior art, the present invention provides a host material, a preparation method, and a dual-host organic electroluminescent material and an organic electroluminescent device containing the same, which have the following excellent effects:

[0085] 1) The present invention provides a host material. By introducing deuterium (D) atom groups at specific positions on the chrysene ring, a compound of Formula I is obtained as the host material. Specifically, D is substituted at the 5, 6, 11, and 12 positions of chrysene. The deuteration positions make the compound structure more symmetric, adjust the molecular spacing and bond energy of the obtained compound, and contribute to improving the luminous efficiency and reducing the driving voltage.

[0086] 2) The present invention provides a dual-host organic electroluminescent material, which is composed of a first host material and a second host material. Among them, the first host material is selected from the compound shown in the structural formula of Formula I, and the second host material is selected from the compound shown in the structural formula of Formula II. After being used in an organic electroluminescent device, it can not only extend the life of the device, but also reduce the driving voltage and improve the luminous efficiency of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0088] Figure 1 1H NMR spectrum of Compound I-1 provided in Example 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0089] Next, in combination with the embodiments of the present invention and the related drawings, the technical solutions of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0090] The present invention specifically discloses a host material, a preparation method, and a dual-host organic electroluminescent material and an organic electroluminescent device containing the same.

[0091] It should be noted that the values given in the following embodiments are as accurate as possible. However, those skilled in the art understand that due to inevitable measurement errors and experimental operation problems, each number should be understood as an approximate number rather than an absolutely accurate value.

[0092] Next, the features and properties of the present invention will be further described in detail in combination with specific embodiments.

[0093] Example 1: Synthesis of Compound I-1

[0094] ;

[0095] CAS: Reactant 1-a: 321939-67-7; CAS: Reactant 1-e: 59151-16-5; CAS: Reactant 1-j: 1883265-32-4

[0096] (1) Reactant 1-a (1.0 eq), silver carbonate (0.24 eq), cyclohexyldiphenylphosphine (0.61 eq), potassium carbonate (1.2 eq), deuterium water (T2O) (24 eq), and toluene were stirred at 120 °C for 7 hours and then cooled to room temperature. The reaction was terminated by adding saturated ammonium chloride aqueous solution, water and dichloromethane were added, and the layers were separated. The organic layer was dried over Na2SO4, filtered, the filtrate was concentrated, isopropanol was added, and the resulting solid was subjected to column chromatography to obtain intermediate 1-b (yield: 48.3%).

[0097] (2) 1-b (1.0 eq), reactant 1-c (1.5 eq), and potassium acetate (2.0 eq) were added to the reactor and purged with nitrogen three times. 1,4-dioxane was added as a solvent and purged with nitrogen three times. Then Pd2(dba)3 (0.01 eq) and X-phos (0.08 eq) were added and purged with nitrogen three times, and the mixture was heated under reflux for 12 hours under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediate 1-d (yield: 83.1%).

[0098] (3) Intermediate 1-d (1.0 eq), reactant 1-e (1.0 eq), and K2CO3 (2 eq) were added to the reactor, and the reactor was purged with nitrogen three times. A mixture of H2O and THF was added as the solvent, and the mixture was purged with nitrogen three times. Then, Pd(Ph3)4 (0.01 eq) was added and the mixture was purged with nitrogen three times. The mixture was heated under reflux for 12 hours under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature. Subsequently, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain intermediate 1-f (yield: 87.7%).

[0099] (4) Intermediate 1-f (1.0 eq), (methoxymethyl)triphenylphosphonium chloride (1.3 eq), and THF were added to the reaction vessel and stirred for 10 minutes. A solution of potassium tert-butoxide was slowly added dropwise at 0 °C, and then the temperature was slowly raised. After stirring at room temperature for 3 hours, distilled water was added thereto. The organic layer was extracted with ethyl acetate successively, and the organic phase was dried over sodium sulfate without further purification. Boron trifluoride anisole and dichloromethane were added to the reaction vessel and stirred for 3 hours. After the reaction was completed, the organic layer was extracted with dichloromethane and water, and then the extracted organic layer was dried over sodium sulfate. The solvent was removed using a rotary evaporator. Thereafter, it was purified by column chromatography to obtain intermediate 1-g (yield: 36.2%).

[0100] (5) Under N2 protection, intermediate 1-g (1.0 eq), reactant 1-h (1.3 eq), PdCl2(dppf) (0.1 eq), and potassium acetate (2.5 eq) were dissolved in DMF, and the temperature was raised to 90 °C and reacted for 12 h. The solvent was removed using a rotary evaporator. Dichloromethane was added to the residue, stirred, and filtered. The remaining material was purified by column chromatography to obtain intermediate 1-i (yield: 76.5%).

[0101] (6) Under N2 protection, intermediate 1-i (1.0 eq), reactant 1-j (1.2 eq), palladium acetate (Pd(OAc)2) (0.15 eq), 2-cyclohexyl-2,4,6-triisopropylbiphenyl (X-Phos) (0.03 eq), and cesium carbonate (Cs2CO3) (2.3 eq) were respectively added to a mixed solvent of toluene, ethanol, and water (4:1:1). The temperature was raised to 90 °C and reacted for 12 h. The solvent was removed using a rotary evaporator. The remaining material was purified by column chromatography, and the filtrate was concentrated using a rotary evaporator to obtain compound I-1 (yield: 72.8%).

[0102] Figure 1 : 1H NMR of compound I-1

[0103] MS measured value MS(ESI, m / z): [M + H]+ = 553.61

[0104] HPLC purity: >99%.

[0105] Example 2: Synthesis of Compound I-95

[0106] ;

[0107] CAS: Reactant 95-a: 870822-84-7; CAS: Reactant 95-j: 2391956-00-4

[0108] (1) Reactant 95-a (1.0 eq), silver carbonate (0.24 eq), cyclohexyldiphenylphosphine (0.61 eq), potassium carbonate (1.2 eq), deuterated water (T2O) (24 eq) and toluene were stirred at 120 °C for 7 hours, then cooled to room temperature. The reaction was terminated by adding saturated ammonium chloride aqueous solution. Water and dichloromethane were added, and the layers were separated. The organic layer was dried over Na2SO4, filtered, and the filtrate was concentrated. Isopropanol was added, and the resulting solid was purified by column chromatography to obtain Intermediate 95-b (yield: 41.6%).

[0109] (2) 95-b (1.0 eq), Reactant 95-c (1.5 eq), and potassium acetate (2.0 eq) were added to the reactor and purged with nitrogen three times. 1,4-dioxane was added as a solvent and purged with nitrogen three times. Then Pd2(dba)3 (0.01 eq) and X-phos (0.08 eq) were added and purged with nitrogen three times. The mixture was heated under reflux for 12 hours under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain Intermediate 95-d (yield: 75.4%).

[0110] (3) Intermediate 95-d (1.0 eq), Reactant 95-e (1.0 eq), and K2CO3 (2 eq) were added to the reactor and purged with nitrogen three times. A mixture of H2O and THF was added as a solvent and purged with nitrogen three times. Then Pd(Ph3)4 (0.01 eq) was added and purged with nitrogen three times. The mixture was heated under reflux for 12 hours under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature. Subsequently, the solvent was removed under reduced pressure, and the crude product was purified by column chromatography to obtain Intermediate 95-f (yield: 83.6%).

[0111] (4) Intermediate 95-f (1.0 eq), (methoxymethyl)triphenylphosphonium chloride (1.3 eq) and THF were added to a reaction vessel and stirred for 10 minutes. A solution of potassium tert-butoxide was slowly added dropwise at 0 °C, and then the temperature was slowly raised. After stirring at room temperature for 3 hours, distilled water was added thereto. The organic layer was extracted with ethyl acetate successively, and the organic phase was dried over sodium sulfate. Without further purification, boron trifluoride etherate and dichloromethane were added to the reaction vessel and stirred for 3 hours. After the reaction was completed, the organic layer was extracted with dichloromethane and water, and then the extracted organic layer was dried over sodium sulfate. The solvent was removed using a rotary evaporator. Thereafter, it was purified by column chromatography to obtain intermediate 95-g (yield: 29.5%).

[0112] (5) Under N2 protection, intermediate 95-g (1.0 eq), reactant 95-h (1.3 eq), PdCl2(dppf) (0.1 eq) and potassium acetate (2.5 eq) were dissolved in DMF. The temperature was raised to 90 °C and the reaction was carried out for 12 h. The solvent was removed using a rotary evaporator. The residue was added to dichloromethane, stirred and filtered. The remaining material was purified by column chromatography to obtain intermediate 95-i (yield: 71.8%).

[0113] (6) Under N2 protection, intermediate 95-i (1.0 eq), reactant 95-j (1.2 eq), palladium acetate (Pd(OAc)2) (0.15 eq) and 2-cyclohexyl-2,4,6-triisopropylbiphenyl (X-Phos) (0.01 - 0.053 eq), cesium carbonate (Cs2CO3) (2.2 eq) were respectively added to a mixed solvent of toluene, ethanol and water (4:1:1). The temperature was raised to 90 °C and the reaction was carried out for 12 h. The solvent was removed using a rotary evaporator. The remaining material was purified by column chromatography. The filtrate was concentrated using a rotary evaporator to obtain compound I-95 (yield: 76.3%).

[0114] Mass spectrometry test value MS(ESI, m / z): [M+H]+ = 558.68

[0115] HPLC purity: >99%.

[0116] The synthesis of the following compounds was completed by referring to the method of the examples of this application. Their molecular formulas and mass spectra are shown in Table 1 below. The mass spectrometer model used for mass spectrometry testing in this application is Waters XEVO TQD, with low precision and ESI source testing.

[0117] Table 1 Molecular formulas and mass spectra

[0118]

[0119] In addition, it should be noted that other compounds of the present application can be obtained by referring to the methods of the above-listed embodiments, so they will not be enumerated one by one here.

[0120] Device Embodiment 1

[0121] 1) Substrate treatment:

[0122] Select the anode ITO / Ag / ITO glass with a surface as the substrate. First, use a stripping solution to remove the protective film on the substrate surface, then perform ultrasonic and spraying processes on the substrate after film removal with deionized water respectively, and finally perform a baking process on the substrate.

[0123] 2) Evaporation process:

[0124] ① Select the cleaned glass substrate and evaporate the hole injection material HI-01 on the substrate with an anode by vacuum evaporation to form a hole injection layer with a thickness of 100 Å. Among them, this layer is co-evaporated with HT-01 and HI-01, and the doping ratio of HI-01 is 3%.

[0125] ② Evaporate the hole transport material HT-01 on the hole injection layer by vacuum evaporation to form a hole transport layer with a thickness of 900 Å.

[0126] ③ Evaporate and deposit the first light-emitting host material compound I-1 and the second light-emitting host material compound LA-009 (Formula I: Formula II = 1:1) and the doping material RD-01 on the hole transport layer by vacuum evaporation in a mass ratio of 97:3 to form a light-emitting layer with a thickness of 400 Å.

[0127] ④ Evaporate the hole blocking layer material HB-01 on the light-emitting layer by vacuum evaporation to form a hole blocking layer with a thickness of 50 Å.

[0128] ⑤ Evaporate and deposit the electron transport material ET-01 and Liq on the hole blocking layer by vacuum evaporation in a mass ratio of 50:50 to form an electron transport layer with a thickness of 300 Å.

[0129] ⑥ Evaporate the electron injection material YB on the electron transport layer by vacuum evaporation to form an electron injection layer with a thickness of 10 Å.

[0130] ⑦ Evaporate the cathode material Mg:Ag(1:9) on the electron injection layer by vacuum evaporation to form a cathode with a thickness of 130 Å.

[0131] ⑧ Evaporate the CP-01 material on the cathode by vacuum evaporation to form a light extraction layer with a thickness of 650 Å, and then a light-emitting device can be obtained.

[0132] The materials involved are as follows:

[0133] 。

[0134] Device Example 2-39

[0135] An organic electroluminescent device was prepared by referring to the same method as in Device Example 1. The only difference is that the host materials of the compounds in Formula I and Formula II are different, as specifically shown in Table 2:

[0136] Comparative Example 1 - Comparative Example 23

[0137] An organic electroluminescent device was prepared by referring to the same method as in Device Example 1. The only difference is that the host materials of the compounds in Formula I and Formula II are different, as specifically shown in Table 2:

[0138]

[0139] 。

[0140] The driving voltage, luminous efficiency, and lifespan of the organic electroluminescent devices obtained from Device Examples 1-39 and Device Comparative Examples 1-23 were characterized at a brightness of 6000 (nits). The test results are shown in Table 2 below.

[0141] Table 2 Test Results of Luminescence Characteristics (Brightness Value is 6000 nits)

[0142]

[0143] As can be seen from Table 2, for Comparative Examples 1 - 10 and Device Examples 1 - 39, they are dual-host material devices, and Comparative Examples 11 - 23 contain only a single host material. Overall, the device performance of the single host material is lower than that of the dual-host material.

[0144] Among the devices containing dual-host materials, the first host material layer is selected from Comparative Compounds 1 - 10. For the devices using the compound of Formula II of the present invention as the second host material, the device performance shows a driving voltage of 3.55 - 3.7 V and an efficiency of 47.5 - 51.9 cd / A; when the first host material is selected from Formula I and the second host material is selected from Formula II, the device performance has been greatly improved, with a driving voltage of 3.19 - 3.45 V, an efficiency of 56.2 - 63.5 cd / A, and a lifespan of 1582 - 1682 h; thus achieving the technical effects of low driving voltage, high efficiency, and long lifespan.

[0145] Compared with Comparative Compounds 4 and 6, the main differences of Formula I lie in the different deuteration positions and the absence of dibenzofuran in the side chain. In Formula I of the present invention, D is substituted at the 5, 6, 11, and 12 positions of chrysene. The deuteration position makes the compound structure more symmetrical, adjusts the intermolecular distance and bond energy of the obtained compound. In the test results, the lifetimes of Comparative Compounds 4 and 6 are further improved compared with other comparative compounds. However, since the deuteration positions of the comparative compounds are at the 5-10 positions of chrysene, there is no improvement in efficiency and driving voltage performance.

[0146] In Formula I, Compound I-1 of the present invention and Comparative Compound 9, Compound I-7 of the present invention and Comparative Compound 2, Compound I-73 of the present invention and Comparative Compound 8, Compound I-146 of the present invention and Comparative Compound 7 are parallel comparative compounds, and the differences lie in the substitution of deuterium on chrysene and the different deuteration positions. The device performance obtained by the test has been significantly improved compared with the comparative example.

[0147] The first host material of the present invention is selected from the compounds represented by the above Formula I structural formula, and the second host material is selected from the following Formula II. After being used in the organic electroluminescent device, it not only prolongs the lifetime of the device, but also reduces the driving voltage and improves the light emission efficiency of the device.

[0148] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A main body material, characterized in that, The structure of the host material is as follows:

2. A dual-host organic electroluminescent material, characterized in that, The dual-host organic electroluminescent material includes a first host material and a second host material. The first host material is the host material described in claim 1; the structure of the second host material is as follows:

3. An organic electroluminescent device, characterized in that, The organic electroluminescent device comprises the host material described in claim 1 or the dual-host organic electroluminescent material described in claim 2.

4. The organic electroluminescent device according to claim 3, characterized in that, The organic electroluminescent device includes a first electrode, a second electrode, and at least one organic electroluminescent material layer disposed between the first electrode and the second electrode; the organic electroluminescent material layer contains the dual-host organic electroluminescent material.

5. The organic electroluminescent device according to claim 3, characterized in that, The dual-host organic electroluminescent material serves as the host material of the light-emitting layer of the organic electroluminescent device.

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