Light-emitting auxiliary material and preparation method and application thereof

Abstract

The application provides a light-emitting auxiliary material and a preparation method and application thereof, and belongs to the field of organic electroluminescence. The light-emitting auxiliary material of the application is connected with triarylamine on a para-folded biphenyl bridged adamantane, one side chain of the triarylamine is an aryl-bridged dibenzofuran, and the other side chain is selected from specific groups. The adamantane has high spatial symmetry and a rigid structure, and can improve the service life of a device to a certain extent. The dibenzofuran is extended through the buffer of an arylene group, the molecular fluidity is enhanced, and thus the light-emitting efficiency of the device is improved. In addition, the dibenzofuran itself has excellent electrochemical stability, is beneficial to improving the mobility of the compound, improving the light-emitting efficiency, and also improving the service life. The organic electroluminescent device using the light-emitting auxiliary material of the application has low driving voltage, high light-emitting efficiency and long service life.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of organic electroluminescence, and relates to a light-emitting auxiliary material and a preparation method and application thereof. BACKGROUND

[0002] Organic electroluminescence (OLED) refers to the phenomenon of converting electric energy into light energy by using organic substances, and an organic light-emitting device using the organic electroluminescence phenomenon generally includes an anode, a cathode, and an organic layer formed between or outside the two electrodes.

[0003] In order to solve the problems of service life and efficiency, a light-emitting auxiliary layer (multi-layer hole transport layer) is usually added between the hole transport layer and the light-emitting layer. The light-emitting auxiliary layer mainly plays the role of assisting the hole transport layer, and is therefore also called the second hole transport layer. The light-emitting auxiliary layer can smoothly move the holes transferred from the anode to the light-emitting layer, and can block the electrons transferred from the cathode to limit the electrons in the light-emitting layer, reduce the potential barrier between the hole transport layer and the light-emitting layer, reduce the driving voltage of the organic electroluminescent device, further increase the utilization rate of holes, and thus improve the light-emitting efficiency and service life of the device. Therefore, the role of the light-emitting auxiliary material is so important.

[0004] The research on organic electroluminescent materials has been widely carried out in academia and industry, but so far the stable and efficient organic layer materials for organic light-emitting devices have not been fully developed, and the industrialization process of the technology still faces many key problems. Therefore, how to develop a new light-emitting auxiliary material has always been a problem to be solved by those skilled in the art. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a light-emitting auxiliary material and a preparation method and application thereof.

[0006] To achieve the purpose of the present application, the following technical solutions are adopted:

[0007] On the one hand, the present application provides a light-emitting auxiliary material, and the structure general formula of the light-emitting auxiliary material is chemical formula I:

[0008]

[0009] In chemical formula I:

[0010] L is independently selected from phenyl, naphthyl or biphenyl;

[0011] R1 and R2 are the same or different from each other, and each is independently selected from hydrogen or phenyl;

[0012] Ar is independently selected from one of the following structures:

[0013]

[0014] * represents the linking site of the group.

[0015] The light-emitting auxiliary material of the present application connects triarylamine on the ortho-folded biphenyl bridged adamantane, one side chain of the triarylamine is aryl (phenylene, biphenylene, naphthylene) bridged dibenzofuran, and the other side chain is selected from specific groups. The adamantane has high spatial symmetry and rigid structure, which can improve the service life of the device to a certain extent, the dibenzofuran extends the system through the buffer of arylene, and the molecular fluidity is enhanced, thereby improving the light-emitting efficiency of the device, and the dibenzofuran itself has excellent electrochemical stability, which is beneficial to improve the mobility of the compound, improve the light-emitting efficiency, and also improve the service life; the organic electroluminescent device using the light-emitting auxiliary material of the present application has low driving voltage, high light-emitting efficiency and long service life.

[0016] Further preferably, the light-emitting auxiliary material has any one of the following structures:

[0017]

[0018] In the present application, further preferably, the light-emitting auxiliary material is any one of the following compounds, but is not limited thereto:

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

[0027]

[0028] The light-emitting auxiliary material of the present application can be prepared by a synthetic method known to those skilled in the art. Alternatively, the following reaction scheme is preferably used for preparation.

[0029]

[0030] In the above formula, Ar, R1, R2, L are defined as in the above chemical formula I, and Hal1, Hal2 are each independently selected from chlorine or bromine.

[0031] The present application utilizes simple raw materials, employs classic Suzuki coupling reaction (Suzuki reaction) and / or Buchwald-Hartwig coupling reaction (Buchwald-Hartwig reaction) to synthesize the light-emitting auxiliary material.

[0032] Specific preparation method:

[0033] Step 1 specifically includes the following steps:

[0034] Synthesis of intermediate 1: dissolve raw material A (1.0 eq), raw material B (1.0-1.2 eq) and basic substance (2.0-3.0 eq) in toluene, under nitrogen protection, then add palladium catalyst tris(dibenzylideneacetone)dipalladium (0.01-0.02 eq) and phosphine ligand tri-tert-butyl phosphine (0.02-0.15 eq), stir uniformly, heat to 100-110℃, reflux for 1-5 hours; detect the reaction by thin layer chromatography, after the reaction is completed, slightly reduce the temperature, filter using diatomite to remove salt and catalyst, after the filtrate is cooled to room temperature, wash with water for three times, retain the organic phase, then extract the water phase with dichloromethane; after the organic phases are combined, remove the solvent using a rotary evaporator; purify by column chromatography using a mixed solution of dichloromethane and petroleum ether (volume ratio 1:5) to obtain intermediate 1.

[0035] Step 2 specifically includes the following steps:

[0036] Synthesis of chemical formula I: dissolve intermediate 1 (1.0 eq), raw material C (1.0-1.2 eq) and basic substance (2.0-3.0 eq) in toluene, under nitrogen protection, then add palladium catalyst tris(dibenzylideneacetone)dipalladium (0.01-0.02 eq) and phosphine ligand tri-tert-butyl phosphine (0.02-0.15 eq), stir uniformly, heat to 110-120℃, reflux for 6-14 hours; detect the reaction by thin layer chromatography, after the reaction is completed, slightly reduce the temperature, filter using diatomite to remove salt and catalyst, after the filtrate is cooled to room temperature, wash with water for three times, retain the organic phase, then extract the water phase with dichloromethane; after the organic phases are combined, remove the solvent using a rotary evaporator; purify by column chromatography using a mixed solution of dichloromethane and petroleum ether (volume ratio 1:6) to obtain chemical formula I.

[0037] The basic substance is selected from sodium tert-butoxide or potassium tert-butoxide.

[0038] On the other hand, the present application provides an organic electroluminescent device including a first electrode, a second electrode, and at least one organic material layer disposed between the first electrode and the second electrode, the organic material layer including a light-emitting auxiliary layer, the light-emitting auxiliary layer including a light-emitting auxiliary material as described above.

[0039] The organic material layer of the organic electroluminescent device of the present application can be formed as a single layer structure, but can also be formed as a multi-layer structure having two or more organic material layers. For example, the organic electroluminescent device of the present application can have a structure including a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting auxiliary layer, a light-emitting layer, an electron transport layer, an electron injection layer, a hole blocking layer, and the like as the organic material layer. However, the structure of the organic electroluminescent device is not limited thereto, and can include a smaller number of organic material layers or a larger number of organic material layers.

[0040] As the anode material, a material having a large work function is generally preferred so that holes are smoothly injected into the organic material layer. Specific examples of the anode material that can be used in the present application include metals such as vanadium, chromium, copper, zinc, and gold, or alloys thereof; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); combinations of a metal and an oxide such as ZnO:Al or SnO2:Sb; conductive polymers such as poly(3-methylthiophene), poly[3,4-(ethylen-1,2-dioxy)thiophene] (PEDOT), polypyrrole, and polyaniline, but are not limited thereto.

[0041] The hole injection material is a material that advantageously receives holes from the anode at a low voltage, and 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. Specific examples of the hole injection material include metal porphyrin, oligothiophene, arylamine-based organic material, hexacyno hexaazatriphenylene-based organic material, quinacridone-based organic material, perylene-based organic material, anthraquinone, and polyaniline-based and polythiophene-based conductive polymers, and the like, but are not limited thereto, and can also contain another compound capable of p-doping.

[0042] The hole transport 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 a material having a high hole mobility is suitable. Specific examples thereof include arylamine-based organic material, conductive polymer, block copolymer having both a conjugated portion and a non-conjugated portion, and the like, but are not limited thereto.

[0043] The light-emitting layer can emit red, green, or blue light, and can be formed of a phosphorescent material or a fluorescent material. The light-emitting material is a material capable of emitting light in the visible region by receiving holes and electrons from the hole transport layer and the electron transport layer, respectively, and combining the holes and the electrons, and is preferably a material having a favorable quantum efficiency for fluorescence or phosphorescence. Specific examples thereof include: 8-hydroxyquinoline aluminum complex (Alq3); carbazole-based compounds; dimeric styryl compounds; bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy) aluminum (BAlq); 10-hydroxybenzoquinoline-metal compounds; benzocarbazole-based, benzothiazole-based, and benzimidazole-based compounds; poly(p-phenylenevinylene) (PPV)-based polymers; spiro compounds; polyfluorene; rubrene; and the like, but are not limited thereto.

[0044] The host material of the light-emitting layer includes fused aromatic ring derivatives, heterocycle-containing compounds, and the like. Specifically, the fused aromatic ring derivatives include anthracene derivatives, pyrene derivatives, naphthalene derivatives, pentacene derivatives, phenanthrene compounds, fluoranthene compounds, and the like, the heterocycle-containing compounds include carbazole derivatives, diphenylfuran derivatives, ladder-type furan compounds, pyrimidine derivatives, and the like, but the materials are not limited thereto.

[0045] The electron transport layer can function to facilitate electron transport, and the electron transport material is a material favorably receiving electrons from the cathode and transporting the electrons to the light-emitting layer, and a material having a high electron mobility is suitable. Specific examples thereof include: Al complexes of 8-hydroxyquinoline; complexes including Alq3; organic radical compounds; hydroxyflavone-metal complexes; and the like, but are not limited thereto. The thickness of the electron transport layer can be 1 nm to 50 nm. The electron transport layer having a thickness of 1 nm or more has an advantage of preventing a decrease in electron transport characteristics, and the thickness of 50 nm or less has an advantage of preventing an increase in driving voltage for enhancing electron mobility caused by the electron transport layer being too thick.

[0046] The electron injection layer can function to facilitate electron injection. The electron injection material is preferably a compound having an ability to transport electrons, having an effect of injecting electrons from the cathode, having an excellent electron injection effect on the light-emitting layer or the light-emitting material, preventing excitons generated in the light-emitting layer from migrating to the hole injection layer, and in addition thereto, having an excellent thin film formation ability. Specific examples thereof include fluorenone, anthraquinone dimethane, biphenylquinone, thiopyran dioxide, oxazole, diazole, triazole, imidazole, perylene tetracarboxylic acid, fluorenylidenemethane, anthrone, and the like, and derivatives thereof, metal complexes, nitrogen-containing 5-membered ring derivatives, and the like, but are not limited thereto.

[0047] As the cathode material, a material having a small work function is generally preferred to allow easy injection of electrons into the organic material layer. Specific examples of the cathode material include: a metal such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or an alloy thereof; a multi-layered structure material such as LiF / Al or LiO2 / Al; and the like, but are not limited thereto.

[0048] The material for other layers in the organic light-emitting device is not particularly limited except that the light-emitting auxiliary layer disclosed herein contains the compound of Formula I.

[0049] In another aspect, the present application provides a display panel including the organic electroluminescent device as described above.

[0050] The display panel according to the present application includes, but is not limited to, a flat panel display, a computer monitor, a medical monitor, a television, a billboard, a lamp for interior or exterior illumination and / or signaling, a head-up display, a fully or partially transparent display, a flexible display, a laser printer, a telephone, a cell phone, a photo album, a personal digital assistant (PDA), a wearable device, a notebook computer, a digital camera, a camcorder, a viewfinder, a micro display, 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, etc.

[0051] The present application has the following advantageous effects over the prior art:

[0052] The compound of the present application is connected by triarylamine with two main structures of adamantane group bridged by biphenyl and arylene bridged dibenzofuran as two main structures.(1) The adamantane group is a rigid structure, which can increase the glass transition temperature, so that the material has better film-forming stability in the process of evaporation, thereby improving the service life of the device, in addition, the adamantane group is connected with the N atom of triarylamine on one end of the benzene ring of biphenyl (para connection), and is ortho connected with another benzene ring, the overall structure is irregular and not easy to crystallize, the compound is more stable and not easy to crack, so that the stability of the device is further improved.(2) The dibenzofuran group is bridged with the N atom of triarylamine through aryl (phenylene, biphenylene, naphthylene), and the system is extended through the buffer of arylene, so that the molecular flowability is enhanced, thereby improving the luminous efficiency of the device, on the other hand, the electrochemical stability of the dibenzofuran group is relatively stable, which is more conducive to improving the migration rate of the compound, which is used in the device, can reduce the hole transport barrier, improve the luminous efficiency, and also improve the service life.(3) The triarylamine itself has a nitrogen atom containing a lone pair of electrons, and the electrons on the nitrogen atom jump under the action of an external electric field, so that the molecule produces a hole, thereby realizing the reverse transmission of the hole; on the other hand, the triarylamine itself has good hole transport capacity, and the dibenzofuran group and other aryl or heteroaryl groups connected on the triarylamine structure are bridged by aryl, which increases the geometric structure on the basis of the non-planar molecular structure, and forms a compound with a large spatial configuration, the unique structure is conducive to the transmission of holes, thereby obtaining high hole transport efficiency, which can improve the luminous efficiency and service life of the device and reduce the driving voltage. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 The nuclear magnetic resonance hydrogen spectrum of compound 2 provided for example 1 of the present application is shown in the following figure. DETAILED DESCRIPTION

[0054] The technical solutions of the present application will be further described through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application, and should not be regarded as specific limitation to the present application.

[0055] In addition, it should be noted that the numerical values given in the following examples are as accurate as possible, but those skilled in the art understand that due to unavoidable measurement errors and experimental operation problems, each number should be understood as an approximate number, rather than an absolutely accurate number.

[0056] The raw materials A-2, A-64, A-96 and A-99 in the following examples 1-4 are the same substance, and are prior art, and the CAS number is 2429888-80-0.

[0057] Example 1

[0058]

[0059] Step 1 specifically includes the following steps:

[0060] Synthesis of intermediate 1: raw material A-2 (1.0 eq, CAS No.: 2429888-80-0), raw material B-2 (1.1 eq, CAS No.: 1795019-74-7) and sodium tert-butoxide (2.0 eq) were dissolved in toluene under nitrogen protection, and then tris(dibenzylideneacetone)dipalladium (0.01 eq) and tri-tert-butylphosphine (0.05 eq) were added, stirred uniformly, and then heated to 100°C and refluxed for 1.5 hours. After the reaction was detected by thin layer chromatography, the temperature was slightly lowered, diatomite was used for filtration to remove the salt and catalyst, and then the filtrate was cooled to room temperature, washed with water three times, and the organic phase was reserved, followed by extraction of the aqueous phase with dichloromethane. After the organic phases were combined, the solvent was removed by a rotary evaporator. The mixture solution of dichloromethane and petroleum ether (1:5 in volume) was used for column chromatography to purify to obtain intermediate 1 (yield: 81.7%).

[0061] Step 2 specifically includes the following steps:

[0062] Synthesis of compound 2: intermediate 1 (1.0 eq), raw material C-2 (1.0 eq, CAS No.: 955959-84-9) and sodium tert-butoxide (2.0 eq) were dissolved in toluene under nitrogen protection, and then tris(dibenzylideneacetone)dipalladium (0.01 eq) and tri-tert-butylphosphine (0.05 eq) were added, stirred uniformly, and then heated to 110°C and refluxed for 10 hours. After the reaction was detected by thin layer chromatography, the temperature was slightly lowered, diatomite was used for filtration to remove the salt and catalyst, and then the filtrate was cooled to room temperature, washed with water three times, and the organic phase was reserved, followed by extraction of the aqueous phase with dichloromethane. After the organic phases were combined, the solvent was removed by a rotary evaporator. The mixture solution of dichloromethane and petroleum ether (1:6 in volume) was used for column chromatography to purify to obtain compound 2 (yield: 82.9%).

[0063] The obtained compound 2 was detected and analyzed, and the results were as follows:

[0064] HPLC purity: >99.8%.

[0065] Mass spectrometry test: Waters XEVO TQD mass spectrometer with ESI source.

[0066] Test value MS (ESI, m / Z): [M+H] + = 698.06.

[0067] Elemental analysis:

[0068] Calculated: C, 89.49; H, 6.21; N, 2.01; O, 2.29;

[0069] Test: C, 89.14; H, 6.38; N, 2.19; O, 2.47.

[0070] NMR spectrum of hydrogen: as shown in Figure 1 (Compound 2).

[0071] Example 2

[0072]

[0073] Step 1 specifically includes the following steps:

[0074] Synthesis of intermediate 1: raw material A-64 (1.0 eq, CAS No.: 2429888-80-0), raw material B-64 (1.1 eq, CAS No.: 1609130-52-0) and sodium tert-butoxide (2.0 eq) were dissolved in toluene, under the protection of nitrogen, and then tris(dibenzylideneacetone)dipalladium (0.01 eq) and tri-tert-butylphosphine (0.05 eq) were added, stirred uniformly, heated to 100°C, and refluxed for 2 hours; the reaction was detected by thin layer chromatography, after the reaction was completed, the temperature was slightly lowered, diatomite was used for filtration to remove salt and catalyst, the filtrate was cooled to room temperature, washed with water for three times, the organic phase was reserved, and then the aqueous phase was extracted with dichloromethane; after the organic phases were combined, the solvent was removed by rotary evaporator; a mixed solution of dichloromethane and petroleum ether (volume ratio 1:5) was used for column chromatography to purify to obtain intermediate 1 (yield: 80.1%).

[0075] Step 2 specifically includes the following steps:

[0076] Synthesis of compound 64: intermediate 1 (1.0 eq), raw material C-64 (1.0 eq, CAS No.: 2923580-92-9) and sodium tert-butoxide (2.0 eq) were dissolved in toluene, under the protection of nitrogen, and then tris(dibenzylideneacetone)dipalladium (0.02 eq) and tri-tert-butylphosphine (0.05 eq) were added, stirred uniformly, heated to 120°C, and refluxed for 12 hours; the reaction was detected by thin layer chromatography, after the reaction was completed, the temperature was slightly lowered, diatomite was used for filtration to remove salt and catalyst, the filtrate was cooled to room temperature, washed with water for three times, the organic phase was reserved, and then the aqueous phase was extracted with dichloromethane; after the organic phases were combined, the solvent was removed by rotary evaporator; a mixed solution of dichloromethane and petroleum ether (volume ratio 1:6) was used for column chromatography to purify to obtain compound 64 (yield: 79.8%).

[0077] The obtained compound 64 was detected and analyzed, and the results were as follows:

[0078] HPLC purity: >99.7%.

[0079] Mass spectrometry test: Mass spectrometer of Waters XEVO TQD type, using ESI source.

[0080] Test value MS (ESI, m / Z): [M+H] + = 824.24.

[0081] Elemental analysis:

[0082] Calculated value: C, 90.37; H, 5.99; N, 1.70; O, 1.94;

[0083] Test value: C, 90.01; H, 6.16; N, 1.90; O, 2.12.

[0084] Example 3

[0085]

[0086] Step 1 specifically includes the following steps:

[0087] Synthesis of intermediate 1: raw material A-96 (1.0 eq, CAS No.: 2429888-80-0), raw material B-96 (1.1 eq, CAS No.: 2447133-71-1) and sodium tert-butoxide (2.0 eq) were dissolved in toluene, under nitrogen protection, then tris(dibenzylideneacetone)dipalladium (0.01 eq) and tri-tert-butylphosphine (0.05 eq) were added, stirred uniformly, heated to 100°C, refluxed for 2 hours; the reaction was detected by thin layer chromatography, after the reaction was completed, the temperature was slightly lowered, filtered using diatomite to remove salt and catalyst, after the filtrate was cooled to room temperature, washed with water for three times, the organic phase was reserved, then the aqueous phase was extracted with dichloromethane; after the organic phases were combined, the solvent was removed using a rotary evaporator; intermediate 1 (yield: 76.6%) was obtained by column chromatography using a mixed solution of dichloromethane and petroleum ether (volume ratio of 1:5) as the developing agent.

[0088] Step 2 specifically includes the following steps:

[0089] Synthesis of compound 96: Intermediate 1 (1.0 eq), raw material C-96 (1.0 eq, CAS No.: 1694655-13-4) and sodium tert-butoxide (2.0 eq) were dissolved in toluene, under the protection of nitrogen, tris(dibenzylideneacetone)dipalladium (0.01 eq) and tri-tert-butylphosphine (0.05 eq) were added, stirred uniformly, heated to 110°C, and refluxed for 10 hours. After the reaction was detected by thin layer chromatography, the temperature was slightly lowered, and the filtrate was filtered using diatomite to remove the salt and catalyst. After the filtrate was cooled to room temperature, it was washed with water three times, and the organic phase was retained. Then, the aqueous phase was extracted with dichloromethane. After the organic phases were combined, the solvent was removed using a rotary evaporator. Compound 96 was obtained by column chromatography using a mixture of dichloromethane and petroleum ether (volume ratio 1:6) as the eluent (yield: 69.4%).

[0090] The obtained compound 96 was detected and analyzed, and the results were as follows:

[0091] HPLC purity: >99.6%.

[0092] Mass spectrometry: Waters XEVO TQD mass spectrometer, ESI source.

[0093] Test value MS (ESI, m / Z): [M+H] + = 863.30.

[0094] Elemental analysis:

[0095] Calculated value: C, 89.06; H, 5.84; N, 3.25; O, 1.85;

[0096] Test value: C, 88.72; H, 6.02; N, 3.42; O, 2.03.

[0097] Example 4

[0098]

[0099] Step 1 specifically includes the following steps:

[0100] Synthesis of intermediate 1: raw material A-99 (1.0 eq, CAS No.: 2429888-80-0), raw material B-99 (1.1 eq, CAS No.: 1023659-21-3) and sodium tert-butoxide (2.0 eq) were dissolved in toluene, under nitrogen protection, then tris(dibenzylideneacetone)dipalladium (0.01 eq) and tri-tert-butylphosphine (0.05 eq) were added, stirred uniformly, heated to 100 °C, refluxed for 2.5 hours; TLC was used to detect the reaction, after the reaction was completed, the temperature was slightly lowered, diatomite was used for filtration to remove the salt and catalyst, after the filtrate was cooled to room temperature, it was washed with water for three times, the organic phase was reserved, then the aqueous phase was extracted with dichloromethane; after the organic phases were combined, the solvent was removed by using a rotary evaporator; intermediate 1 (yield: 75.3%) was obtained by column chromatography using a mixed solution of dichloromethane and petroleum ether (volume ratio 1:5).

[0101] Step 2 specifically includes the following steps:

[0102] Synthesis of compound 99: intermediate 1 (1.0 eq), raw material C-99 (1.0 eq, CAS No.: 1084334-69-9) and sodium tert-butoxide (2.0 eq) were dissolved in toluene, under nitrogen protection, then tris(dibenzylideneacetone)dipalladium (0.01 eq) and tri-tert-butylphosphine (0.05 eq) were added, stirred uniformly, heated to 110 °C, refluxed for 10 hours; TLC was used to detect the reaction, after the reaction was completed, the temperature was slightly lowered, diatomite was used for filtration to remove the salt and catalyst, after the filtrate was cooled to room temperature, it was washed with water for three times, the organic phase was reserved, then the aqueous phase was extracted with dichloromethane; after the organic phases were combined, the solvent was removed by using a rotary evaporator; compound 99 (yield: 71.6%) was obtained by column chromatography using a mixed solution of dichloromethane and petroleum ether (volume ratio 1:6).

[0103] The obtained compound 99 was detected and analyzed, and the results were as follows:

[0104] HPLC purity: >99.7%.

[0105] Mass spectrometry test: Waters XEVO TQD mass spectrometer, ESI source.

[0106] Test value MS (ESI, m / Z): [M+H] + = 864.41.

[0107] Elemental analysis:

[0108] Calculated value: C, 90.35; H, 6.18; N, 1.62; O, 1.85;

[0109] The test values ​​were: C, 90.02; H, 6.34; N, 1.79; O, 2.02.

[0110] Examples 5-98

[0111] The following compounds were synthesized according to the synthesis methods described in Examples 1 to 4. The mass spectrometer was a Waters XEVOTQD, which has low precision, so an ESI source was used for testing. The mass spectrometry values ​​are shown in Table 1 below.

[0112] Table 1 Mass spectrometry values ​​of Examples 5-98

[0113]

[0114]

[0115]

[0116]

[0117] In addition, it should be noted that other compounds of the present invention can be obtained by referring to the synthesis methods of the embodiments listed above, so they will not be listed one by one here.

[0118] Device Example 1: Fabrication of Red Organic Light Emitting Device (OLED)

[0119] The structure of the fabricated OLED device is: ITO anode / HIL / HTL / Prime / EML / HBL / ETL / EIL / cathode / CPL.

[0120] a. ITO anode: The coating thickness is... The ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate was cleaned twice with distilled water, ultrasonically washed for 30 minutes, then repeatedly cleaned twice with distilled water, ultrasonically washed for 10 minutes. After washing, it was ultrasonically washed sequentially with methanol, acetone, and isopropanol (5 minutes each time), dried, and then transferred to a plasma cleaner for 5 minutes. Finally, it was sent to an evaporation machine, where other functional layers were sequentially deposited on the substrate as the anode.

[0121] b. HIL (Hole Injection Layer): The evaporation rate was determined by vacuum evaporation of hole injection layer materials HT-1 and P-dopant. The evaporation rate ratio of HT-1 to P-dopant was 97:3, and the thickness was 10 nm.

[0122] c. HTL (Hole Transport Layer): At a certain evaporation rate, HT-1 of 130 nm was vacuum-deposited on the hole injection layer as a hole transport layer.

[0123] d、Prime (light-emitting auxiliary layer): Compound 1 provided in the above embodiment was vacuum evaporated on the hole transport layer as a light-emitting auxiliary layer at an evaporation rate of 0.1 A / s to a thickness of 10 nm.

[0124] e、EML (light-emitting layer): Then, Host-1 and Dopant were vacuum evaporated as a light-emitting layer on the light-emitting auxiliary layer at an evaporation rate of 0.1 A / s to a thickness of 20 nm. The evaporation rate ratio of Host-1 and Dopant was 97:3.

[0125] f、HBL (hole blocking layer): HB-1 was vacuum evaporated as a hole blocking layer at an evaporation rate of 0.1 A / s to a thickness of 5 nm.

[0126] g、ETL (electron transport layer): ET-1 and Liq were vacuum evaporated as an electron transport layer at an evaporation rate of 0.1 A / s to a thickness of 30 nm. The evaporation rate ratio of ET-1 and Liq was 50:50.

[0127] h、EIL (electron injection layer): Yb was evaporated as an electron injection layer at an evaporation rate of 0.1 A / s to a thickness of 1 nm.

[0128] i、Cathode: Magnesium and silver were evaporated as a cathode at an evaporation rate ratio of 1:9 to a thickness of 13 nm to obtain an OLED device.

[0129] j、CPL (light extraction layer): CPL-1 was vacuum evaporated as a light extraction layer on the cathode at an evaporation rate of 0.1 A / s to a thickness of 65 nm.

[0130] K、Subsequently, the substrate on which evaporation was completed was encapsulated. First, a coating device was used to perform a coating process on the cover plate after cleaning with UV glue, then the coated cover plate was moved to the pressing section, the substrate on which evaporation was completed was placed on the end of the cover plate, and finally the substrate and the cover plate were bonded under the action of the bonding device, and the UV glue was simultaneously cured by light.

[0131] Structure of the compounds used in the device:

[0132]

[0133] Referring to the method provided in Device Embodiment 1, the corresponding compounds in Table 2 were respectively selected to replace Compound 1 to perform evaporation of the light-emitting auxiliary layer, and the corresponding organic electroluminescent devices were prepared and were respectively recorded as Device Embodiments 2 to 57.​​​​​​​

[0134] Device Comparative Example 1-Device Comparative Example 14:

[0135] This comparative example provides an organic electroluminescence device, the preparation method of which is only different from that of device example 1 in that the organic electroluminescence device is prepared by replacing the light-emitting auxiliary material (compound 1) in the above device example 1 with the existing comparative compounds a-n for evaporation. The chemical structural formula of the comparative compounds a-n is as follows:

[0136]

[0137] The driving voltage, luminous efficiency and lifetime of the organic electroluminescence devices obtained from the above device examples 1-57 and device comparative examples 1-14 were characterized at a brightness of 6000 (nits), and the test results are as shown in Table 2 below:

[0138] Table 2

[0139]

[0140]

[0141]

[0142] Device Example 58: Preparation of a green organic electroluminescence device

[0143] The structure of the prepared OLED device is: ITO anode / HIL / HTL / light-emitting auxiliary layer / EML / ETL / EIL / cathode / light extraction layer.

[0144] a, ITO anode: the ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 1.1 / 0.02 / 1.1 μm was cleaned in distilled water for 2 times, ultrasonic washing for 30 min, and then repeatedly cleaned with distilled water for 2 times, ultrasonic washing for 10 min. After washing, methanol, acetone and isopropanol were sequentially ultrasonic washed (5 min each time), dried, then transferred to a plasma cleaning machine for washing for 5 min, and then sent to an evaporation machine. The substrate was used as an anode, and other functional layers were sequentially evaporated thereon. b, HIL (hole injection layer): the hole injection layer materials HT-1 and P-dopant were vacuum evaporated at an evaporation rate of 0.1 A / s. The evaporation rate ratio of the HT-2 and P-dopant was 97:3, and the thickness was 10 nm.

[0145] c, HTL (hole transport layer): the hole transport layer materials HT-1 and P-dopant were vacuum evaporated at an evaporation rate of 0.1 A / s. The evaporation rate ratio of the HT-2 and P-dopant was 97:3, and the thickness was 10 nm.

[0146] c, HTL (hole transport layer): the hole transport layer materials HT-1 and P-dopant were vacuum evaporated at an evaporation rate of 0.1 A / s. The evaporation rate ratio of the HT-2 and P-dopant was 97:3, and the thickness was 10 nm. ​HT-2 was vacuum deposited on the hole injection layer as a hole transport layer at a deposition rate of 130 nm.

[0147] d. Light-emitting auxiliary layer: Compound 1 provided in the above examples was vacuum deposited on the hole transport layer as a light-emitting auxiliary layer at a deposition rate of 10 nm.

[0148] e. EML (light-emitting layer): Then, on the above light-emitting auxiliary layer, a double host material (Host-2 and Host-3) and a dopant material (Dopant-2) were vacuum deposited as a light-emitting layer at a thickness of 200 nm at a deposition rate of 200 nm, with a Host-2 to Host-3 ratio of 50:50. The deposition rate ratio of the double Host and the Dopant was 90:10.

[0149] f. HBL (hole blocking layer): HB-2 was vacuum deposited as a hole blocking layer at a thickness of 5 nm at a deposition rate of 5 nm.

[0150] g. ETL (electron transport layer): ET-2 and Liq were vacuum deposited as an electron transport layer at a thickness of 30 nm at a deposition rate of 30 nm, with a ET-2 to Liq ratio of 50:50.

[0151] h. EIL (electron injection layer): Yb was deposited as an electron injection layer at a thickness of 1.0 nm at a deposition rate of 1.0 nm.

[0152] i. Cathode: Magnesium and silver were deposited at a thickness of 18 nm at a deposition rate ratio of 1:9 to obtain an OLED device.

[0153] j. Light extraction layer: CPL-2 was vacuum deposited on the cathode as a light extraction layer at a thickness of 70 nm at a deposition rate of 70 nm.

[0154] K. Subsequently, the substrate on which the deposition was completed was encapsulated. First, a cleaning cover plate was coated with UV glue using a glue coating device, and then the coated cover plate was moved to a pressing section, the substrate on which the deposition was completed was placed on the end of the cover plate, and finally the substrate and the cover plate were attached under the action of the attaching device, and the UV glue was simultaneously cured by light irradiation.

[0155] Structure of the compound used in the device:

[0156]

[0157] ​​​​​​​Referring to the method provided in device embodiment 58 above, the corresponding compounds in Table 3 are respectively selected to replace compound 1 to perform evaporation of the light-emitting auxiliary layer, and the corresponding organic electroluminescent devices are prepared and recorded as device embodiments 58-114, respectively.

[0158] Device comparative examples 15-28:

[0159] This comparative example provides an organic electroluminescent device, and the only difference between the preparation method of the organic electroluminescent device and device embodiment 58 is that the organic electroluminescent device is evaporated by using the existing comparative compounds a-n to replace the light-emitting auxiliary material (compound 1) in device embodiment 58. The chemical structural formula of the comparative compounds a-n is as follows:

[0160]

[0161] The driving voltage, luminous efficiency and lifetime of the organic electroluminescent devices obtained by device embodiments 58-114 and device comparative examples 15-28 above are characterized at a brightness of 15000 (nits), and the test results are as follows

[0162] Table 3

[0163]

[0164]

[0165]

[0166]

[0167] As can be seen from Table 2 and Table 3, whether it is a green light device or a red light device, changing the connection position and transforming the substituent group will change the performance of the device. The organic electroluminescent device prepared by using the light-emitting auxiliary material provided by the present application has improved efficiency and lifetime compared with the organic electroluminescent device prepared by using the comparative compound.

[0168] Comparative compound a and compound 2 are parallel comparative examples, the difference between them is that the adamantane group in comparative compound a is connected to both ends of a straight biphenyl group, the structure is too regular, easy to crystallize, and the stability is reduced, while in compound 2 of the present application, the adamantane group is connected to the benzene ring at one end of the biphenyl group (para connection), and is ortho connected to the other benzene ring, the overall structure is irregular and not easy to crystallize, the compound is more stable and not easy to crack and quench, so that the stability of the device is improved.

[0169] Comparative compound c and compound 6 are parallel examples, the difference is that in comparative compound c, the adamantane group and the triarylamine N atom are bridged by a phenylene group, while in compound 6 of the present application, the adamantane group and the triarylamine N atom are bridged by a biphenylylene group, which increases the conjugated area, improves the light-emitting efficiency, and also improves the driving voltage and the lifetime.

[0170] Comparative compounds d, f, g and compounds 63, 60, 67 are parallel examples, respectively, the difference is that in comparative compounds d, f, g, the dibenzofuran group is directly bonded to the triarylamine N atom, while in compounds 63, 60, 67 of the present application, the dibenzofuran group is bridged to the triarylamine N atom by an arylene group (phenylene, biphenylene, naphthylene), which extends the system through the buffering of phenylene, biphenylene, naphthylene, and enhances the molecular fluidity, thereby improving the light-emitting efficiency of the device.

[0171] Comparative compounds h, i and compounds 44, 41 are parallel examples, the difference is that in the comparative compound, the N atom in the triarylamine is connected to a 9-methyl-9-phenylfluorene group (the phenyl group is connected to the 9-position of the fluorene), while in the compound of the present application, the N atom is connected to a 9, 9-dimethylfluorene group substituted by a phenyl group (the substitution position of the phenyl ring is the 2-position of the fluorene), which effectively extends the conjugated system, and in the compound of the present application, the adamantane and the triarylamine N atom are bridged by a biphenylene group, which is longer than the conjugated system of the comparative compound in which the middle is bridged by a phenyl group, so that the light-emitting efficiency is further improved.

[0172] Comparative compound l and compound 1 are parallel examples, the difference is that compared with comparative compound l, in compound 1 of the present application, the triarylamine N atom is connected to a biphenyl group, and then connected to an adamantane group. The adamantane group is a rigid structure, which can increase the glass transition temperature, so that the film-forming stability is better during the evaporation process, thereby improving the device lifetime.

[0173] Comparative compound n and compound 16 are parallel examples, the difference is that in comparative compound n, the group on one of the arylamines is a 9-methylfluorene bridged to the triarylamine N atom by a phenylene group, while in compound 16 of the present application, a dibenzofuran group is bridged to the triarylamine N atom by a phenylene group. The electrochemical stability of dibenzofuran is relatively more stable, which is more conducive to improving the migration rate of the compound, and when used in a device, it can reduce the hole transport energy barrier and improve the light-emitting efficiency, and also improve the lifetime.

[0174] The applicant states that the luminescent auxiliary material of the present application and the preparation method and application thereof are illustrated by the above-mentioned examples, but the present application is not limited to the above-mentioned examples, i.e. it does not mean that the present application must rely on the above-mentioned examples to be implemented. It should be understood by those skilled in the art that any improvement of the present application, equivalent replacement of the raw materials selected by the present application, addition of auxiliary ingredients, selection of specific modes, etc. all fall within the protection scope and disclosure scope of the present application.

Claims

1. A luminescence auxiliary material, characterized by, The light-emitting auxiliary material has any one of the following structures: wherein: R1and R2, the same as or different from each other, are each independently selected from hydrogen or phenyl; Ar is independently selected from one of the following structures: * represents the connecting site of the group.

2. The luminescence aid material according to claim 1, characterized in that, The light-emitting auxiliary material is any one of the following compounds:

3. An organic electroluminescent device, characterized by comprising The organic electroluminescent device comprises a first electrode, a second electrode, and at least one organic material layer disposed between the first electrode and the second electrode, the organic material layer comprising a light-emitting auxiliary layer, the light-emitting auxiliary layer comprising the light-emitting auxiliary material according to claim 1 or 2.

4. The organic electroluminescent device according to claim 3, characterized in that The organic material layer further comprises any one of a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, an electron transport layer, an electron injection layer, or a combination of at least two of a hole blocking layer.

5. A display panel, characterized by, The display panel comprises the organic electroluminescent device according to claim 3 or 4.

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