Double-host material and application thereof

Abstract

The invention provides a double-host material and application thereof. The double-host material comprises a first host compound with a structure shown in a formula I and a second host compound with a structure shown in a formula II. According to the invention, the dual-host material is compounded by compounds with specific structures, is used for preparing the organic electroluminescent device, and can obviously reduce the driving voltage of the device, improve the luminous efficiency of the device and prolong the service life of the device.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic optoelectronic materials, and particularly relates to a dual host material and its application. Background Art

[0002] Organic light-emitting devices (OLEDs) are self-luminous devices. Due to their characteristics such as low driving voltage, high resolution, high brightness, fast response time, and flexibility, they have received extensive attention in the panel display device industry.

[0003] Currently, OLED display technology has been applied in fields such as smart phones and tablet computers, and will further expand to large-size application fields such as televisions. However, compared with the actual product application requirements, the performance of OLEDs such as luminous efficiency and service life still needs to be further improved.

[0004] In OLED devices, the luminous efficiency can be greatly improved by the host-guest doping of the light-emitting layer. This is because the radiative transition of triplet excitons of most organic molecules is forbidden and contributes little to electroluminescence. By doping organic metal complexes such as platinum, iridium, and osmium, the triplet excitons of organic molecules are transferred to the triplet state of the metal complex, greatly improving the efficiency of organic light-emitting devices. However, triplet-triplet annihilation occurs during the transfer process of triplet excitons, resulting in energy loss and causing efficiency roll-off of organic light-emitting devices.

[0005] In addition, the host material is also required to have a high glass transition temperature and pyrolysis temperature to achieve thermal stability, high electrochemical stability, so as to achieve long life, easy formability of amorphous thin films, good adhesion with adjacent layers, and immobility between layers.

[0006] Therefore, developing a host material with high luminous efficiency and long service life is an urgent technical problem in this field. Summary of the Invention

[0007] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a dual host material and its application. The organic light-emitting device including the dual host material has high luminous efficiency, long service life, and low driving voltage.

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

[0009] In the first aspect, the present invention provides a dual host material, which includes a first host compound with a structure shown in Formula I and a second host compound with a structure shown in Formula II.

[0010]

[0011] Wherein, R 1 、R2 Each independently selected from substituted or unsubstituted C6-C30 (such as C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C21, C22, C24, C26, C28, C30, etc.) aryl, substituted or unsubstituted 6-30-membered heteroaryl (such as 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 26, 28, 30, etc.), substituted or unsubstituted C10-C30 fused ring group (such as C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C21, C22, C24, C26, C28, C30, etc.), C3-C30 cycloalkyl (such as C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, C19, C20, C21, C22, C24, C26, C28, C30, etc.); T 1 , T 2 , T 3 , T 4 , T 5 , T 6 , T 7 , T 8 , T 9 , T 10 , T 11 , T 12 , T 13 , T 14 , T 15 , T 16 Each independently selected from hydrogen or deuterium; L 1 , L 2 Each independently selected from a single bond, substituted or unsubstituted C6-C30 arylene, substituted or unsubstituted C6-C30 heteroarylene; Ar 1 and Ar 2 Each independently selected from substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 6-30-membered heteroaryl, substituted or unsubstituted C10-C30 fused ring group; and at least one CH 2 or CH in the C10-C30 fused ring group can each independently be replaced by N or O;

[0012] R 3 Selected from any of the following groups:

[0013]

[0014] *Represents the connection position.

[0015] The substituents of the substitution include deuterium, cyano group or a straight-chain or branched-chain alkyl group of C1-C6 (for example, it can be C1, C2, C3, C4, C5, C6).

[0016] In the present invention, the first host compound with a specific structure has a faster hole mobility; the second host compound with a specific structure has a fast electron mobility. By compounding the first host compound and the second host compound with specific structures, the hole and electron mobilities can be balanced, so that the double host material can increase excitons in the light-emitting layer, thereby improving the luminous efficiency and service life of the device, and reducing the driving voltage.

[0017] Preferably, the second host compound of the structure shown in Formula II is selected from any one of 2-a to 2-o, or any one of 2-a to 2-o substituted by substituents.

[0018]

[0019] The substituents of the substitution include cyano group, deuterium or a straight-chain or branched-chain alkyl group of C1-C6.

[0020] Preferably, the L 1 、L 2 Each independently is selected from any one of a single bond, a phenylene group, a naphthylene group, a thiophene group, and a furan group.

[0021] Preferably, the Ar 1 、Ar 2 Each independently is selected from at least one of a phenyl group, a deuterated phenyl group, a naphthyl group, a deuterated naphthyl group, an anthracene group, a biphenyl group, a thiophene group, a chromium group, a furan group, a benzofuran group, a furan group and a deuterated phenyl group, a phenanthrene group, a tert-butyl and phenyl group, a benzoxazine group, a benzothiophene group, a fluorene group, a diphenylfluorene group, a phenylnaphthoxazole group or a fluoranthene group.

[0022] Preferably, the second host compound of the structure shown in Formula II is selected from any one of H2-1 to H2-300.

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038] Preferably, the R 1 and R 2 are each independently selected from any one of phenyl, deuterated phenyl, naphthyl, deuterated naphthyl, biphenyl, furyl, thienyl, cyclohexylphenyl, furylbiphenyl, furyl-deuterated phenyl, benzonaphthofuryl, tert-butylphenyl, tert-butylbiphenyl, biphenyl, fluorenyl, triphenyl, benzofluorenyl, phenanthryl, phenylnaphthalene, fluorenyl or dibenzofurylbiphenylcarbonitrile.

[0039] Preferably, the first host compound of the structure shown in Formula I is selected from any one of H1-1 to H1-300.

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055] In the present invention, the "substitution" means that a hydrogen atom bonded to a carbon atom of a compound is changed to another substituent, and there is no limitation on the substitution position as long as it is the position where the hydrogen atom is substituted, that is, the position where the substituent can substitute, and when two or more substituents are substituted, the two or more substituents can be the same or different from each other.

[0056] The heteroaryl group is a monocyclic aromatic group containing at least one heteroatom and / or a polycyclic aromatic ring group containing at least one heteroatom, and the heteroatoms include, but are not limited to, O, S, N, P or B.

[0057] In the present invention, the fused ring group includes fused aromatic rings sharing at least two carbon atoms, and also includes fused aromatic rings connected by a single bond.

[0058] Preferably, the mass ratio of the first host compound to the second host compound is (10-90):(90-10), wherein the specific values in (10-90) can be, for example, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, etc.; the specific values in (90-10) can be, for example, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, etc., preferably the ratio of the two is 30-70:70-30, and more preferably 60-40:40-60. The most preferred mass ratios are 40:60, 45:55, 50:50, 55:45, 60:40.

[0059] In the present invention, the reaction route of the first host compound having the structure shown in Formula I is as follows:

[0060]

[0061] wherein, R 1 、R 2 、T 1 、T 2 、T 3 、T 4 、T 5 、T6 , T 7 , T 8 , T 9 , T 10 , T 11 , T 12 , T 13 , T 14 , T 15 , T 16 Each independently is selected from the same range as formula I; X is selected from halogen; the halogen includes fluorine, chlorine, bromine or iodine, preferably chlorine, and bromine is the second preference.

[0062] In the present invention, the specific preparation method of the first host compound having the structure shown in formula I includes:

[0063] In the presence of a protective atmosphere (including but not limited to nitrogen), a compound having the structure shown in formula I-1, a compound having the structure shown in formula I-2, sodium tert-butoxide, toluene, Pd 2 (dba) 3 and P(t-Bu) 3 are mixed and then refluxed at 110 - 120 °C for 18 - 24 h. After the reaction is completed, it is cooled to room temperature, mixed with pure water of the same volume as the reaction solution, stirred, allowed to stand for liquid separation, and subjected to column chromatography to obtain the first host compound having the structure shown in formula I.

[0064] In the present invention, the reaction route of the second host compound having the structure shown in formula II is as follows:

[0065]

[0066] The specific preparation method includes:

[0067] (1) Under the condition of a protective gas, a compound having the structure shown in formula II-1, bis(pinacolato)diboron, potassium acetate, 1,4-dioxane, Pd 2 (dba) 3 and X-Phos are mixed and then refluxed at 100 °C to obtain an intermediate;

[0068] (2) Under the condition of a protective gas, the intermediate prepared in step (1), a compound having the structure shown in formula II-2, K 2 CO 3 , THF and H 2 O, Pd(pph 3 ) 4 are mixed and then refluxed at 80 °C to obtain the second host compound having the structure shown in formula II.

[0069] Second aspect, the present invention provides an organic electroluminescent material, and the organic electroluminescent material includes the dual host material according to the first aspect.

[0070] Preferably, a doping material is further included in the organic electroluminescent material.

[0071] Preferably, the mass ratio of the dual host material to the doping material in the organic electroluminescent material is (5 - 199):1, where specific values in (5 - 199) can be, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 30, 40, 50, 60, 70, 80, 90, 100, 120, 140, 160, 180, 190, etc.; more preferably (5 - 100):1, and even more preferably (5 - 15):1.

[0072] Third aspect, the present invention provides an organic electroluminescent device, and the organic electroluminescent device includes the dual host material according to the first aspect or the organic electroluminescent material according to the second aspect.

[0073] In the present invention, the organic electroluminescent device includes a first electrode, a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a second electrode arranged in sequence; the material of the light emitting layer includes the dual host material according to the first aspect or the organic electroluminescent material according to the second aspect.

[0074] In the present invention, the preparation method of the light emitting layer includes, but is not limited to, forming the light emitting layer from the organic electroluminescent material by solution coating method and vacuum deposition method; here, the solution coating method means spin coating, dip coating, inkjet printing, screen printing, spraying method, etc., but is not limited thereto.

[0075] In the present invention, the first electrode is an anode.

[0076] As the anode material, generally, in order to enable holes to be smoothly injected into the organic layer, a material with a large work function is preferred. Anode materials that can be used in the present invention include: metals, such as vanadium, chromium, copper, zinc, etc. metals or their alloys; metal oxides, such as zinc oxide, indium oxide, indium tin oxide (ITO) or indium zinc oxide (IZO); a combination of metal and oxide, such as ZnO / Al or SnO 2 / Sb; conductive polymers, such as poly(3 - methylthiophene), polypyrrole or polyaniline; but is not limited thereto. In some embodiments of the present invention, the anode is an ITO anode.

[0077] In the present invention, the material of the hole injection layer is a hole material that receives holes from the anode under low voltage, and the highest occupied molecular orbital (HOMO) of the material of the hole injection layer is preferably between the work function of the anode material and the HOMO of the surrounding organic material layer. Commonly used hole injection materials include, but are not limited to, metal porphyrins, oligothiophenes, arylamine-based organic materials, benzonitrile-based organic materials, quinacridone-based organic materials, polyaniline-based or polythiophene-based conductive polymers, etc.

[0078] In the present invention, the hole transport layer material is a material that can receive holes from the anode or the hole injection layer and transport the holes to the light-emitting layer, and has a high hole mobility. In certain embodiments of the present invention, the hole transport layer material includes, but is not limited to, arylamine-based organic materials, conductive polymers, block copolymers having both a conjugated part and a non-conjugated part, etc.

[0079] In the present invention, the electron transport layer plays a role in promoting electron transport. The electron transport layer material is a material that is used to receive electrons from the cathode and transport the electrons to the light-emitting layer, and has a high electron mobility. It includes: Al complexes of 8-hydroxyquinoline; organic radical compounds, etc., but is not limited thereto. The thickness of the electron transport layer is set to be 1 nm to 50 nm. For example, it can be 1 nm, 2 nm, 4 nm, 6 nm, 8 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, etc.; it can prevent the decline of electron transport characteristics and prevent the increase of driving voltage due to the too thick electron transport layer.

[0080] In the present invention, the electron injection layer can play a role in promoting electron injection, and the electron injection material preferably has the ability to transport electrons, has an electron injection effect from the cathode, has an excellent electron injection effect on the light-emitting layer or the light-emitting material, prevents the excitons generated in the light-emitting layer from migrating to the hole injection layer, and in addition, has an excellent thin film forming ability. Specific examples thereof include fluorenone, anthraquinone dimethane, biphenylquinone, thiopyran dioxide, imidazole, perylene tetracarboxylic acid, fluoreneylidene methane, anthrone, etc. and their derivatives, metal complexes, nitrogen-containing five-membered ring derivatives, etc., but are not limited thereto.

[0081] In the present invention, the second electrode is the cathode.

[0082] As the cathode material, generally, in order to facilitate the injection of electrons into the organic layer, a material with a small work function is preferred. Specific examples of the cathode material include: metals, such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, lead, etc. metals or their alloys; multi-layer structure materials, such as LiF / Al or LiO 2 / Al; but is not limited thereto. In certain embodiments of the present invention, the cathode material is Al.

[0083] In the present invention, the organic electroluminescent device may be a top-emitting type, a bottom-emitting type, or a double-sided emitting type.

[0084] The numerical ranges described in the present invention include not only the above-listed point values, but also any point values between the above numerical ranges not listed. Due to space limitations and for the sake of brevity, the specific point values included in the ranges of the present invention are not exhaustively listed herein.

[0085] The system refers to an equipment system, a device system, or a production device.

[0086] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0087] The dual host material provided by the present invention is prepared by compounding a first host compound with a specific structure and a second host compound with a specific structure, and is used as the luminescent layer material of the organic electroluminescent device, which is beneficial to improving the luminescence efficiency of the device, extending the service life, and reducing the driving voltage. Specific Embodiments

[0088] 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 on the present invention.

[0089] Preparation Example 1

[0090] Preparation of the first host compound H1-1

[0091] (1) Under nitrogen protection, (9-phenyl-9H-carbazol-4-yl)boronic acid (156 mmol), 2-bromo-4-chlorobenzaldehyde (156 mmol), potassium carbonate (312 mmol), tetrahydrofuran (THF), and water were added to a round-bottom flask, and tetrakis(triphenylphosphine)palladium (3.1 mmol) was added under nitrogen protection, and the mixture was refluxed for 12 hours. After the reaction was completed, liquid separation was performed. After concentrating the organic layer, column chromatography was used for separation to obtain intermediate 1-a (41.9 g, yield 70%, HPLC > 99%, mass spectrometry test: theoretical value 381.86, test value 381.95), and the reaction route is shown as follows.

[0092]

[0093] (2) Intermediate 1-a (82.7 mmol), (methoxymethyl)triphenylphosphonium chloride (107.51 mmol), and THF (414 mL) were added to a reaction vessel and stirred for 10 minutes. A solution of 120 mL of potassium tert-butoxide in THF (1 M / L) was slowly added dropwise at 0 °C. Then, the temperature was slowly raised, and after stirring at room temperature for 3 hours, distilled water was added thereto. After the reaction was completed, the organic layer was extracted with ethyl acetate in sequence, the organic phase was dried over sodium sulfate, and the solvent was removed by a rotary evaporator. Then, it was purified by column chromatography to obtain Intermediate 1-b (32.2 g, yield 95%, HPLC > 99%, mass spectrometry test: theoretical value 409.91, measured value 409.96), and the reaction route is shown below.

[0094]

[0095] (3) Compound Intermediate 1-b (72.6 mmol), boron trifluoride etherate (18.3 mL), and dichloromethane (730 mL) were added to a 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, and the solvent was removed by a rotary evaporator. Thereafter, it was purified by column chromatography to obtain Intermediate Compound 1-1 (16.4 g, yield 60%, HPLC > 99%, mass spectrometry test: theoretical value 377.87, measured value 377.73).

[0096]

[0097] (4) Under a nitrogen protection system, Intermediate 1-1 (59.81 mmol), N-(biphenyl-3-yl)dibenzo[b,d]furan-3-amine (59.81 mmol), and sodium tert-butoxide (119.63 mmol) were added to a reaction flask, 200 mL of toluene was added thereto, and the catalyst Pd 2 (dba) 3 (1.79 mmol) and P(t-Bu) 3 (2.39 mmol) were added under nitrogen protection. The mixture was refluxed at 120 °C for 24 h, cooled to 25 °C, 200 mL of pure water was added thereto, stirred for 30 min, allowed to stand for liquid separation, and then purified by column chromatography to obtain the first main compound H1-1 (24.3 g, yield 60%, HPLC > 99%, mass spectrometry test: theoretical value 676.82, measured value 676.93), and the reaction route is shown below.

[0098]

[0099] Preparation of the first main compound H1-4

[0100] Under a nitrogen protection system, weigh intermediate 1-1 (59.81 mmol), N-(phenyl-d5) dibenzo[b,d]furan-3-amine (59.81 mmol), and sodium tert-butoxide (119.63 mmol) into a reaction flask, add 200 mL of toluene, and add catalyst Pd under nitrogen protection 2 (dba) 3 (1.79 mmol) and P(t-Bu) 3 (2.39 mmol). Under nitrogen protection, reflux at 120 °C for 24 h, then cool to 25 °C, add 200 mL of pure water thereto, stir for 30 min, then let it stand for liquid separation, separate the liquid, and perform column chromatography to obtain the first main compound H1-4 (23.5 g, yield 65%, HPLC > 99%, mass spectrometry test: theoretical value is 605.75, test value is 605.87). The reaction route is as follows

[0101]

[0102] Preparation of the first main compound H1-19

[0103] Under a nitrogen protection system, weigh intermediate 1-1 (59.81 mmol), N-(dibenzo[B,D]furan-3-yl)dibenzo[B,D]furan-2-amine (59.81 mmol), and sodium tert-butoxide (119.63 mmol) into a reaction flask, add 200 mL of toluene, and add catalyst Pd under nitrogen protection 2 (dba) 3 (1.79 mmol) and P(t-Bu) 3 (2.39 mmol). Under nitrogen protection, reflux at 120 °C for 24 h, then cool to 25 °C, add 200 mL of pure water, stir for 30 min, then let it stand for liquid separation, separate the liquid, and perform column chromatography to obtain the first main compound H1-19 (29.3 g, yield 71%, HPLC > 99%, mass spectrometry test: theoretical value is 690.80, test value is 690.92). The reaction route is as follows

[0104]

[0105] Preparation of the first main compound H1-29

[0106] Under a nitrogen protection system, weigh intermediate 1-1 (59.81 mmol), N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzo[B,D]furan-2-amine (59.81 mmol), and sodium tert-butoxide (119.63 mmol) into a reaction flask, add 200 mL of toluene, and add catalyst Pd under nitrogen protection 2 (dba) 3(1.79 mmol) and P(t-Bu)3 (2.39 mmol) were refluxed at 120 °C for 24 h under nitrogen protection, then cooled to 25 °C, 200 mL of pure water was added, stirred for 30 min, allowed to stand for liquid separation, and separated by column chromatography to obtain the first host compound H1-29 (27.01 g, yield 63%, HPLC > 99%, mass spectrometry test: theoretical value 716.88, measured value 716.98), and the reaction route is shown below.

[0107]

[0108] Preparation of the first host compound H1-62

[0109] Under a nitrogen protection system, intermediate 1-1 (59.81 mmol), 1,2'-dinaphthylamine (59.81 mmol), and sodium tert-butoxide (119.63 mmol) were weighed into a reaction flask, 200 mL of toluene was added, and the catalyst Pd 2 (dba) 3 (1.79 mmol) and P(t-Bu) 3 (2.39 mmol) were refluxed at 120 °C for 24 h under nitrogen protection, then cooled to 25 °C, 250 mL of pure water was added, stirred for 30 min, allowed to stand for liquid separation, and separated by column chromatography to obtain the first host compound H1-62 (23.74 g, yield 65%, HPLC > 99%, mass spectrometry test: theoretical value 610.76, measured value 610.92), and the reaction route is shown below.

[0110]

[0111] Preparation of the first host compound H1-108

[0112] Under a nitrogen protection system, intermediate 1-1 (59.81 mmol), reactant 1,2'-dinaphthylamine (59.81 mmol), and sodium tert-butoxide (119.63 mmol) were weighed into a reaction flask, 200 mL of toluene was added, and the catalyst Pd 2 (dba) 3 (1.79 mmol) and P(t-Bu) 3 (2.39 mmol) were refluxed at 120 °C for 24 h under nitrogen protection, then cooled to 25 °C, 250 mL of pure water was added, stirred for 30 min, allowed to stand for liquid separation, and separated by column chromatography to obtain the first host compound H1-108 (26.56 g, yield 72%, HPLC > 99%, mass spectrometry test: theoretical value 616.78, measured value 616.89), and the reaction route is shown below.

[0113]

[0114] Preparation Example 2

[0115] Preparation of the second host compound H2-1

[0116] 3-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)benzo[b]naphtho[1,2-d]furan (12.7 mmol), 2-(6-chloro-1-naphthyl)-4,6-diphenyl-1,3,5-triazine (11.5 mmol), K 2 CO 3 (23 mmol) and Pd(PPh 3 ) 4 (0.03 mmol) were added to a flask, and toluene (30 mL), ethanol (10 mL) and water (10 mL) were added thereto, and the mixture was refluxed at 90 °C for 6 hours. After the reaction was completed, the organic layer was extracted with ethyl acetate, and the remaining water was removed with sodium sulfate, and then the organic layer was dried. Thereafter, purification by column chromatography gave the second host compound H2-1 (4.96 g, yield 75%, HPLC > 99%, mass spectrometry: theoretical value 575.67, measured value 575.74), and the reaction route is shown below.

[0117]

[0118] Preparation of the second host compound H2-2

[0119] 3-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)benzo[b]naphtho[1,2-d]furan (12.7 mmol), 2-(6-chloronaphthalen-1-yl)-4,6-di(naphthalen-2-yl)-1,3,5-triazine (11.5 mmol), K 2 CO 3 (23 mmol) and Pd(PPh 3 ) 4 (0.03 mmol) were added to a flask, dissolved in toluene (30 mL), ethanol (10 mL) and water (10 mL), and then refluxed at 90 °C for 6 hours. After the reaction was completed, the organic layer was extracted with ethyl acetate, and the remaining water was removed with sodium sulfate, and then the organic layer was dried. Thereafter, purification by column chromatography gave the second host compound H2-2 (5.59 g, yield 72%, HPLC > 99%, mass spectrometry: theoretical value 675.79, measured value 675.90), and the reaction route is shown below.

[0120]

[0121] Preparation of the second host compound H2-18

[0122] (1) Under a nitrogen protection system, 5-chloro-2-formylphenylboronic acid (156 mmol), 4-bromodibenzofuran (156 mmol), potassium carbonate (312 mmol), THF and H 2 O were added to a round-bottom flask, and tetrakis(triphenylphosphine)palladium (3.1 mmol) was added under nitrogen protection, and the mixture was refluxed for 12 hours. After the reaction was completed, liquid separation was carried out. After concentrating the organic layer, it was separated by column chromatography to obtain intermediate 2-a-1 (33.6 g, yield 73%, HPLC>99%, mass spectrometry test: theoretical value 306.75, test value 306.86).

[0123] (2) Intermediate 2-a-1 (90 mmol), (methoxymethyl)triphenylphosphonium chloride (117 mmol) and THF (450 mL) were added to a reaction vessel and stirred for 10 minutes. Then, a potassium tert-butoxide solution (potassium tert-butoxide dissolved in THF to form a solution with a concentration of 1 M / L, and the dropping volume was 130.5 mL) was slowly added dropwise at 0 °C, and the temperature was slowly raised to room temperature and stirred at room temperature for 3 hours; then distilled water was added thereto. After the reaction was completed, the organic layer was extracted with ethyl acetate in sequence. After drying the extracted organic layer with magnesium sulfate, the solvent was removed by a rotary evaporator. Thereafter, it was purified by column chromatography to obtain intermediate 2-b-1 (28.02 g, yield 93%, HPLC>99%, mass spectrometry test: theoretical value 334.80, test value 334.95).

[0124] (3) Compound intermediate 2-b-1 (80 mmol), boron trifluoride etherate (20 mL) and dichloromethane (800 mL) were added to a reaction vessel and stirred for 3 hours. After the reaction was completed, the organic layer was extracted with dichloromethane and water together. After drying the extracted organic layer with magnesium sulfate, the solvent was removed by a rotary evaporator. Thereafter, it was purified by column chromatography to obtain intermediate 2-c-1 (15.26 g, yield 63%, HPLC>99%, mass spectrometry test: theoretical value 302.76, test value 302.88).

[0125] (4) Under a nitrogen protection system, intermediate 2-c-1 (50 mmol), bis(pinacolato)diboron (100 mmol), and potassium acetate (100 mmol) were weighed into a reaction flask, 1,4-Dioxane was added, and the catalyst Pd 2 (dba) 3(1 mmol), X-Phos (8 mmol), reflux at 110 °C for 18 h, then cool to 25 °C, add pure water, stir for 30 min, then let it stand for liquid separation, separate the liquid, and perform column chromatography to obtain intermediate compound 2-A-1 (16.90 g, yield 86%, HPLC > 99%, mass spectrometry test: theoretical value 394.28, measured value 394.39).

[0126] The reaction routes of steps (1)-(4) are as follows:

[0127]

[0128] (5) Add intermediate compound 2-A-1 (12.7 mmol), 2-chloro-4-(dibenzo[b,d]furan-1-yl)-6-(phenyl-d5)-1,3,5-triazine (11.5 mmol), K 2 CO 3 (23 mmol) and Pd(PPh 3 ) 4 (0.03 mmol) to a flask, dissolve with toluene (30 mL), ethanol (10 mL) and water (10 mL), then reflux at 90 °C for 6 h. After the reaction is completed, extract the organic layer with ethyl acetate, remove the remaining water with sodium sulfate, and then dry the organic layer. Thereafter, obtain the second main compound H2-18 (4.31 g, yield 63%, HPLC > 99%, mass spectrometry test: theoretical value 594.68, measured value 594.81), and the reaction route is as follows.

[0129]

[0130] Preparation of the second main compound H2-29

[0131] Add intermediate compound 2-A-1 (12.7 mmol), 2-chloro-4-(dibenzo[B,D]thiophen-3-yl)-6-phenyl-1,3,5-triazine (11.5 mmol), K 2 CO 3 (23 mmol) and Pd(PPh 3 ) 4(0.03 mmol) was added to a flask and dissolved in toluene (30 mL), ethanol (10 mL) and water (10 mL), and then refluxed at 90 °C for 6 hours. After the reaction was completed, the organic layer was extracted with ethyl acetate, and the remaining water was removed with sodium sulfate, and then the organic layer was dried. Thereafter, the second host compound H2-29 (4.87 g, yield 70%, HPLC > 99%, mass spectrometry test: theoretical value 605.72, measured value 605.84) was obtained by column chromatography, and the reaction route is shown below.

[0132]

[0133] Preparation of the second host compound H2-37

[0134] The intermediate compound 2-A-1 (12.7 mmol), 2-chloro-4-(2-naphthyl)-6-phenyl-1,3,5-triazine (11.5 mmol), K 2 CO 3 (23 mmol) and Pd(PPh 3 ) 4 (0.03 mmol) was added to a flask and dissolved in toluene (30 mL), ethanol (10 mL) and water (10 mL), and then refluxed at 90 °C for 6 hours. After the reaction was completed, the organic layer was extracted with ethyl acetate, and the remaining water was removed with sodium sulfate, and then the organic layer was dried. Thereafter, the second host compound H2-37 (4.74 g, yield 75%, HPLC > 99%, mass spectrometry test: theoretical value 549.63, measured value 549.75) was obtained by column chromatography, and the reaction route is shown below.

[0135]

[0136] Preparation of the second host compound H2-127

[0137] The intermediate compound 2-A-2 (12.7 mmol), 2-chloro-4-(dibenzo[b,d]furan-1-yl)-6-phenyl-1,3,5-triazine (11.5 mmol), K 2 CO 3 (23 mmol) and Pd(PPh 3 ) 4(0.03 mmol) was added to a flask and dissolved in toluene (30 mL), ethanol (10 mL) and water (10 mL). Then it was refluxed at 90 °C for 6 hours. After the reaction was completed, the organic layer was extracted with ethyl acetate, and the remaining water was removed with magnesium sulfate, and then the organic layer was dried. Thereafter, the second host compound H2-127 (5.66 g, yield 74%, HPLC > 99%, mass spectrometry test: theoretical value 665.75, test value 665.88) was obtained by column chromatography. The reaction route is as follows.

[0138]

[0139] Among them, the preparation method of intermediate 2-A-2 is the same as that of intermediate 2-A-1, except that 4-bromodibenzofuran is replaced with 2-bromo-8-phenyldibenz[b,d]furan. The reaction route of intermediate 2-A-2 is as follows.

[0140]

[0141] Preparation of the second host compound H2-139

[0142] The intermediate compound 2-A-2 (12.7 mmol), 2-chloro-4-(dibenzo[B,D]thiophen-3-yl)-6-phenyl-1,3,5-triazine (11.5 mmol), K 2 CO 3 (23 mmol) and Pd(PPh 3 ) 4 (0.03 mmol) were added to a flask and dissolved in toluene (30 mL), ethanol (10 mL) and water (10 mL). Then it was refluxed at 90 °C for 6 hours. After the reaction was completed, the organic layer was extracted with ethyl acetate, and the remaining water was removed with magnesium sulfate, and then the organic layer was dried. Thereafter, the second host compound H2-139 (5.72 g, yield 73%, HPLC > 99%, mass spectrometry test: theoretical value 681.81, test value 681.92) was obtained by column chromatography. The reaction route is as follows.

[0143]

[0144] Preparation of the second host compound H2-146

[0145] The intermediate compound 2-A-2 (12.7 mmol), 2-chloro-4-(2-naphthyl)-6-phenyl-1,3,5-triazine (11.5 mmol), K 2 CO 3 (23 mmol) and Pd(PPh 3 ) 4(0.03 mmol) was added to a flask and dissolved in toluene (30 mL), ethanol (10 mL) and water (10 mL). Then, it was refluxed at 90 °C for 6 hours. After the reaction was completed, the organic layer was extracted with ethyl acetate, and the remaining water was removed with sodium sulfate. Then, the organic layer was dried. Thereafter, the second host compound H2-146 (5.54 g, yield 77%, HPLC > 99%, mass spectrometry test: theoretical value 625.73, measured value 625.88) was obtained by column chromatography. The reaction route is shown below.

[0146]

[0147] In addition, it should be noted that other compounds of the present invention can be obtained by referring to the synthesis methods of the above-listed examples, so they will not be listed one by one here.

[0148] Examples 1-39, Comparative Examples 1-3

[0149] Examples 1-39 and Comparative Examples 1-3 respectively provide a host material. The formulation of the host material is shown in Table 1. Among them, for the scheme of the dual-host material including the first host compound and the second host compound, the mass ratio of the first host compound to the second host compound is 60:40. In Table 1, "-" indicates that the host material does not contain this compound. The structures of D-1 and D-2 are shown below.

[0150]

[0151] Table 1

[0152]

[0153]

[0154] An organic electroluminescent device, and the preparation method of the organic electroluminescent device includes:

[0155] (1) An ITO (indium tin oxide) glass substrate with a thickness of was washed twice in distilled water, ultrasonically washed for 30 min, then repeatedly washed twice with distilled water, ultrasonically washed for 10 min. After the washing was completed, it was ultrasonically washed with methanol, acetone, and isopropanol in sequence (each washing for 5 min), dried, and then transferred to a plasma cleaner for washing for 5 min to obtain an ITO anode.

[0156] (2) In an evaporation coater, a hole injection layer with a thickness of was vacuum-evaporated on the surface of the ITO anode obtained in step (1). The HIL structure is as follows:

[0157]

[0158] (3) Vacuum evaporate HTL on the surface of the hole injection layer obtained in step (2), with a thickness of to obtain a hole transport layer. The structure of HTL is as follows:

[0159]

[0160] (4) Evaporate the light-emitting layer material on the surface of the hole transport layer, and perform linear gradient co-evaporation using the multi-source co-evaporation method, with a thickness of to obtain a light-emitting layer; the material of the light-emitting layer includes a double-host material and a doping material. The mass ratio of the first host compound to the second host compound is 60:40, and the mass ratio of the double-host material to the doping material is 10:1. The double-host materials are the host materials provided in Examples 1 to 23 and Comparative Examples 1 to 19 respectively; the structure of the doping material is as follows:

[0161]

[0162] (5) Evaporate BAlq on the surface of the light-emitting layer obtained in step (4), with a thickness of to form a hole blocking layer, and the structure is as follows:

[0163]

[0164] (6) Vacuum evaporate ETL on the surface of the hole blocking layer obtained in step (5), with a thickness of to obtain an electron transport layer. The structure of ETL is as follows:

[0165]

[0166] (7) Vacuum evaporate Liq on the surface of the electron transport layer obtained in step (6), with a thickness of to obtain an electron injection layer.

[0167]

[0168] (8) Evaporate Al on the surface of the electron injection layer obtained in step (7) to form a cathode, and then the organic electroluminescent device can be obtained.

[0169] Test the driving voltage, luminous efficiency of the organic electroluminescent device at a brightness of 1000 nits, and the time (lifetime; T95) required for the brightness to decrease from 100% to 95% at a brightness of 5000 nits. The test results are shown in Table 2.

[0170] Table 2

[0171]

[0172]

[0173] As can be seen from Table 2, the dual-host material provided by the present invention, using the first host compound and the second host compound with specific structures, can reduce the driving voltage of the device, improve the light-emitting efficiency of the device, and extend the service life of the device.

[0174] By comparing Examples 1 to 23 with Comparative Examples 4 to 19, it can be seen that when the host material of the light-emitting layer is a mixture of the first host compound and the second host compound, the light-emitting efficiency and service life can be greatly improved. If only any one of them is selected, the light-emitting efficiency of the device will be greatly reduced, the service life will be significantly shortened, and the voltage will increase.

[0175] By comparing Examples 1 to 23 with Comparative Example 3, it can be seen that the light-emitting efficiency of Comparative Example 3 is 32.7 cd / A, the driving voltage is 3.56 V, and the service life is 359 h. While the light-emitting efficiency of Examples 1 to 23 of the present invention is 37.3 - 43.3 cd / A, which is significantly higher than that of Comparative Example 3; the driving voltage is 2.52 - 2.97 V, which is significantly lower than that of Comparative Example 3; the service life is 462 - 500 h, which is much higher than that of Comparative Example 3. Therefore, it can be seen that using the first host compound with a specific structure and the second host compound with a specific structure of the present invention as the host material of the light-emitting layer can greatly improve the light-emitting efficiency and service life.

[0176] From the test results of Comparative Examples 1 to 2 and Comparative Examples 4 to 19 where the device only has a single host material, it can be seen that when the light-emitting layer material includes the first host compound or the second host compound with the specific structure provided by the present invention, the device performance is slightly higher than that of the single-host compound in the prior art, and the host material provided by the present invention has better performance.

[0177] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A dual-host material, characterized in that, the dual-host material comprises a first host compound having a structure shown in Formula I and a second host compound having a structure shown in Formula II; Among them, R 1 , R 2 are each independently selected from any one of substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 6-30-membered heteroaryl, substituted or unsubstituted C10-C30 fused ring group, and C3-C30 cycloalkyl; T 1 、T 2 、T 3 、T 4 、T 5 、T 6 、T 7 、T 8 、T 9 、T 10 、T 11 、T 12 、T 13 、T 14 、T 15 、T 16 Each independently selected from hydrogen or deuterium; L 1 and L 2 each independently selected from any one of a single bond, a substituted or unsubstituted C6-C30 arylene group, and a substituted or unsubstituted C6-C30 heteroarylene group; Ar 1 and Ar 2 each independently selected from any one of substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted 6-30-membered heteroaryl, and substituted or unsubstituted C10-C30 fused ring group; and at least one CH 2 or CH in the C10-C30 fused ring group may each independently be replaced by N or O; R 3 Selected from any one of the groups shown below: * represents the connection position; the substituents of the substitution include deuterium, cyano group or a straight-chain or branched-chain alkyl group having 1 to 6 carbon atoms.

2. The dual-host material according to claim 1, characterized in that, the second host compound having the structure shown in Formula II is selected from any one of 2-a to 2-o, or any one of 2-a to 2-o substituted by substituents; the substituents of the substitution include cyano group, deuterium or a straight-chain or branched-chain alkyl group having 1 to 6 carbon atoms.

3. The dual-host material according to claim 1 or 2, characterized in that, The L 1 , L 2 are each independently selected from any one of a single bond, a phenylene group, a naphthylene group, a thiophene group, and a furan group; Preferably, the Ar 1 and Ar 2 are each independently selected from at least one of phenyl, deuterated phenyl, naphthyl, deuterated naphthyl, anthryl, biphenyl, thienyl, chromyl, furyl, benzofuryl, furyl-deuterated phenyl, phenanthryl, tert-butyl-phenyl, benzoxazine, benzothienyl, fluorenyl, diphenylfluorenyl, phenylnaphthoxazole or fluoranthenyl.

4. The dual-host material according to any one of claims 1 to 3, characterized in that, the second host compound having the structure shown in Formula II is selected from any one of H2-1 to H2-300; 5. The dual-host material according to any one of claims 1 to 4, characterized in that, The R 1 , R 2 are each independently selected from any one of phenyl, deuterated phenyl, naphthyl, deuterated naphthyl, biphenyl, furyl, thienyl, cyclohexylphenyl, furylbiphenyl, furyl deuterated phenyl, benzonaphthofuryl, tert-butylphenyl, tert-butylbiphenyl, biphenyl, fluorenyl, triphenyl, benzofluorenyl, phenanthryl, phenylnaphthalene, fluorenyl or dibenzofurylbiphenylbenzonitrile group.

6. The dual-host material according to any one of claims 1 to 5, characterized in that, the first host compound having the structure shown in Formula I is selected from any one of H1-1 to H1-300; 7. The dual-host material according to any one of claims 1 to 6, characterized in that, the mass ratio of the first host compound to the second host compound is (10 to 90):(90 to 10), further preferably (30 to 70):(70 to 30), and more preferably (60 to 40):(40 to 60).

8. An organic electroluminescent material, characterized in that, the organic electroluminescent material comprises the dual-host material according to any one of claims 1 to 7.

9. The organic electroluminescent material according to claim 8, characterized in that, the organic electroluminescent material further comprises a doping material; preferably, in the organic electroluminescent material, the mass ratio of the dual-host material to the doping material is (5 to 199):1, further preferably (5 to 100):1, and more preferably (5 to 15):

1.

10. An organic electroluminescent device, characterized in that, the organic electroluminescent device comprises the dual-host material according to any one of claims 1 to 7 or the organic electroluminescent material according to claim 8 or 9.

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