Luminescent auxiliary material as well as preparation method and application thereof

Abstract

The invention provides a light-emitting auxiliary material as well as a preparation method and application thereof, and belongs to the field of organic electroluminescent materials, the structural general formula of the light-emitting auxiliary material is a chemical formula I. An organic electroluminescent device using the light-emitting auxiliary material provided by the invention has high light-emitting efficiency under the condition of keeping relatively low driving voltage. The material has excellent thermal stability, high luminous efficiency and long service life.

Description

Technical Field

[0001] The invention belongs to the field of organic electroluminescence and relates to a luminescence auxiliary material and a preparation method and application thereof. Background Art

[0002] Organic electroluminescent devices (OLEDs) have a multi-layer "sandwich" structure, which specifically includes electrode material film layers and organic functional materials sandwiched between different electrode film layers, including: hole injection layer, hole transport layer, luminescence auxiliary layer, electron blocking layer, luminescent layer, electron buffer layer, hole blocking layer, electron transport layer, electron injection layer, etc.

[0003] The luminescent auxiliary layer is arranged between the hole transport layer and the luminescent layer, which can reduce the potential barrier between the hole transport layer and the luminescent layer, reduce the driving voltage of the organic electroluminescent device, and further increase the utilization rate of holes, thereby improving the luminous efficiency and life of the device and reducing the driving voltage. However, there are few functional materials that can form the luminescent auxiliary layer. In particular, the morphology of the luminescent auxiliary layer material in the device after evaporation is an amorphous disordered film. The morphology of the evaporated film affects the evaporation temperature and the life and luminous efficiency of the OLED device. Therefore, it is particularly important to develop higher performance organic functional materials to meet the requirements of panel manufacturers in mass production of organic electroluminescent displays. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention aims to provide a luminescent auxiliary material and a preparation method and application thereof. The luminescent auxiliary material of the present invention is applied to an organic electroluminescent device, which can make the device have excellent thermal stability, high luminous efficiency and long service life while maintaining a low driving voltage.

[0005] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0006] In one aspect, the present invention provides a luminescence auxiliary material, the general structural formula of the luminescence auxiliary material is Chemical Formula I:

[0007]

[0008] Ar1 and Ar2 are each independently selected from a substituted or unsubstituted C6-C30 aryl group, wherein the substituent in the substituted C6-C30 aryl group is selected from deuterium, an unsubstituted C1-C6 alkyl group, a C1-C6 alkyl group fully or partially substituted by deuterium, or a C6-C18 aryl group.

[0009] The luminescence auxiliary material of the present invention connects benzofluorene and adamantane through a spiro ring, and further connects a triarylamine group side chain of an aromatic group to the spiro ring side of the fluorene. The luminescence auxiliary material is applied to a device, so that the device has excellent thermal stability, high luminescence efficiency and long service life while maintaining a low driving voltage.

[0010] Further preferably, Ar1 and Ar2 are each independently selected from a substituted or unsubstituted C6-C18 aryl group, wherein the substituent in the substituted C6-C18 aryl group is selected from deuterium, an unsubstituted C1-C6 alkyl group, a C1-C6 alkyl group fully or partially substituted by deuterium, or a C6-C12 aryl group.

[0011] More preferably, Ar1 and Ar2 are each independently selected from any one of the following groups:

[0012]

[0013] The position of * is the connection site of the group;

[0014] R1-R9 are each independently selected from hydrogen, deuterium, unsubstituted C1-C6 alkyl, and C1-C6 alkyl fully or partially substituted by deuterium;

[0015] n1 is independently selected from 0, 1, 2, 3, 4, 5;

[0016] n2 and n5 are each independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9;

[0017] n3 and n8 are each independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13;

[0018] n4 and n6 are each independently selected from 0, 1, 2, 3, 4, 5, 6, 7;

[0019] n7 and n9 are each independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11.

[0020] Further preferably, the luminescence auxiliary material is selected from the following compounds having any one of the structures of Chemical Formula I-1 to Chemical Formula I-6:

[0021]

[0022] The definitions of Ar1 and Ar2 are the same as those in Formula I.

[0023] In the above technical solution, it is further preferred that the luminescence auxiliary material is any one of the following compounds, but not limited thereto:

[0024] .

[0025] The luminescence auxiliary material of the present invention can be prepared by a synthesis method known to those skilled in the art. Alternatively, the following preparation method is preferably used for preparation.

[0026] The method for preparing the luminescence auxiliary material of the present invention comprises the following steps:

[0027] (1) Raw material A reacts with raw material B to obtain intermediate 1;

[0028] (2) Intermediate 1 is reacted in the presence of methanesulfonic acid to obtain intermediate 2;

[0029] (3) The intermediate 2 reacts with the raw material C to obtain the luminescent auxiliary material shown in the chemical formula I;

[0030] The reaction process of the preparation method is as follows:

[0031] .

[0032] Preferably, the molar ratio of raw material A to raw material B in step (1) is 1.1-1.5:1, for example, 1.1:1, 1.2:1, 1.3:1, 1.4:1 or 1.5:1.

[0033] Preferably, the reaction in step (1) is carried out in the presence of n-butyl lithium, and the molar ratio of n-butyl lithium to raw material B is 1.1-1.5:1 (e.g., 1.1:1, 1.2:1, 1.3:1, 1.4:1 or 1.5:1); the n-butyl lithium is added to the reaction system at -78°C.

[0034] Preferably, the reaction in step (1) is carried out in an organic solvent, and the organic solvent is selected from tetrahydrofuran.

[0035] Preferably, the reaction temperature in step (1) is room temperature (15-25° C.), and the reaction time is 2-14 h, for example 2 h, 5 h, 8 h, 10 h, 12 h or 14 h.

[0036] Preferably, the molar ratio of the intermediate 1 to methanesulfonic acid in step (2) is 3-10:1, for example 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 7:1, 8:1, 9:1 or 10:1.

[0037] Preferably, the reaction in step (2) is carried out in an organic solvent selected from toluene and tetrahydrofuran.

[0038] Preferably, the reaction in step (2) is carried out at room temperature (15-25° C.) and the reaction time is 15-60 min, for example, 15 min, 20 min, 30 min, 40 min, 50 min or 60 min.

[0039] Preferably, the molar ratio of the intermediate 2 to the raw material C in step (3) is 1:1.0-1.3, for example, 1:1.0, 1:1.1, 1:1.2 or 1:1.3.

[0040] Preferably, the reaction in step (3) is carried out in the presence of an alkaline substance, the alkaline substance is sodium tert-butoxide or potassium tert-butoxide, and the molar ratio of the alkaline substance to the raw material C is 2.0-4.0:1, for example, 2.0:1, 2.5:1, 2.8:1, 3.0:1, 3.5:1, 3.8:1 or 4.0:1.

[0041] Preferably, the reaction in step (3) is carried out in the presence of a palladium catalyst, wherein the palladium catalyst is selected from tris(dibenzylideneacetone)dipalladium, tetrakis(triphenylphosphine)palladium, palladium dichloride, [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium, palladium acetate or bis(triphenylphosphine)palladium dichloride; and the molar ratio of the palladium catalyst to the raw material C is 0.01-0.03:1, for example 0.01:1, 0.02:1 or 0.03:1.

[0042] Preferably, the reaction in step (3) is carried out in the presence of a phosphine ligand, wherein the phosphine ligand is selected from tri-tert-butyl phosphine, triethyl phosphine, trimethyl phosphine, triphenyl phosphine, potassium diphenylphosphine or di-tert-butyl phosphine chloride; and the molar ratio of the phosphine ligand to the raw material C is 0.02-0.15:1, for example 0.02:1, 0.05:1, 0.08:1, 0.10:1, 0.13:1 or 0.15:1.

[0043] Preferably, the reaction temperature in step (3) is 100-120°C, for example 100°C, 105°C, 110°C, 115°C or 120°C, and the reaction time is 2-18h, for example 2h, 5h, 8h, 10h, 12h, 16h or 18h.

[0044] As a preferred technical solution, the preparation process of the luminescence auxiliary material is as follows:

[0045]

[0046] In the above formula, Ar1 and Ar2 are as defined in the above chemical formula I.

[0047] With respect to the complex raw materials which are not disclosed, the classical lithiation reaction, Buchwald–Hartwig coupling reaction, is adopted and applied to the present invention.

[0048] Specific preparation method:

[0049] Step 1 specifically includes the following processes:

[0050] At -78°C, raw material A (1.1-1.5 eq) was added to a reaction bottle containing tetrahydrofuran, the nitrogen was replaced 3 times, and the mixture was stirred for 10-30 minutes. n-Butyl lithium (1.1-1.5 eq) was slowly added to the reaction bottle, and the reaction was continued for 2-4 hours. Raw material B (1.0 eq) was dissolved in tetrahydrofuran and then slowly dripped into the reaction bottle. After stirring evenly, refrigeration was stopped, and the mixture was heated to room temperature and the reaction was continued for 2-14 hours. The reaction was detected by thin layer chromatography. After the reaction was completed, water and dichloromethane were added for separation and extraction. The organic phases were combined and concentrated. Intermediate 1 was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (volume ratio of 1:2-1:10)

[0051] Step 2 specifically includes the following processes:

[0052] A mixed solution of toluene (3.0-10.0 eq) and THF (3.0-10.0 eq) was added to a reaction flask, and then intermediate 1 (1.0 eq) was added, and the mixture was stirred at room temperature until dissolved. Subsequently, methanesulfonic acid (3.0-10.0 eq) was added to the reaction flask, and the mixture was reacted for 15-60 min. The reaction was detected by thin layer chromatography. After the reaction was completed, water and dichloromethane were added for separation and extraction. The organic phases were combined and concentrated, and intermediate 2 was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (volume ratio of 1:2-1:10).

[0053] Step 3 specifically includes the following processes:

[0054] Add intermediate 2 (1.0 eq), raw material C (1.0-1.3 eq), toluene and sodium tert-butoxide (2.0-4.0 eq) into a reaction flask, and then add tri(dibenzylideneacetone)dipalladium (0.01-0.03 eq) and tri-tert-butylphosphine (0.02-0.15 eq) under nitrogen, raise the temperature to 100-120° C. and stir to react for 2-18 hours; detect the reaction by thin layer chromatography, and after determining that the reaction is complete, add water and dichloromethane for extraction and separation, combine the organic phases and concentrate, and purify by column chromatography using a mixed solution of dichloromethane and petroleum ether (volume ratio of 1:4-1:10) to obtain chemical formula I.

[0055] On the other hand, the present invention provides a red organic light-emitting device, comprising a first electrode, a second electrode and at least one organic layer disposed between the first electrode and the second electrode, wherein the organic layer comprises the light-emitting auxiliary material as described above.

[0056] Preferably, the organic layer includes a luminescence auxiliary layer, and the luminescence auxiliary layer contains the luminescence auxiliary material as described above.

[0057] The organic layer of the red organic light-emitting device of the present invention may be formed as a single-layer structure, but may also be formed as a multilayer structure having two or more organic material layers. For example, the organic light-emitting device of the present invention may 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, etc. as an organic layer. However, the structure of the organic light-emitting device is not limited thereto, and may include a smaller number of organic material layers or a larger number of organic layers.

[0058] Except that the light-emitting auxiliary layer disclosed herein includes the compound represented by Chemical Formula I, there is no special limitation on the materials of other layers in the OLED device.

[0059] In another aspect, the present invention provides an organic light-emitting device, comprising the organic electroluminescent device as described above.

[0060] The organic light-emitting device described in the present invention includes but is not limited to flat panel displays, computer monitors, medical monitors, televisions, billboards, lights for internal or external lighting and / or signals, head-up displays, fully transparent or partially transparent displays, flexible displays, laser printers, telephones, mobile phones, photo albums, personal digital assistants (PDAs), wearable devices, laptops, digital cameras, camcorders, viewfinders, microdisplays, three-dimensional displays, virtual reality or augmented reality displays, vehicles, video walls including multiple displays tiled together, theater or stadium screens, light therapy devices and signs, etc.

[0061] Compared with the prior art, the present invention has the following beneficial effects:

[0062] The compound of the present invention is a benzofluorene group and a 9-position adamantane group connected to the fluorene as the parent core (benzofluorene and adamantane are connected through a spiro ring), and the side of the fluorene group fused with a phenyl group is connected to a triarylamine group containing an aromatic group. As a light-emitting auxiliary layer material, the device can have excellent light-emitting efficiency and long service life, while maintaining a low driving voltage.

[0063] The benzofluorene structure itself has strong rigidity, and the fused ring system makes the overall structure have high thermal stability, which can maintain the integrity of the structure at high temperatures. In addition, benzofluorene has a low HOMO energy level, which is conducive to the efficient injection and transmission of holes, can significantly improve the mobility of carriers, reduce charge recombination losses, and thus effectively improve the luminous efficiency of the device.

[0064] Benzofluorene is further connected to the adamantyl group through a spiro ring to obtain a more unique rigid three-dimensional structure. The adamantyl group is an electron-rich group that can increase the electron density of the system and thus improve the hole migration ability of the compound. The adamantyl group has a large steric hindrance, so it can reduce the intermolecular stacking effect, thereby improving the morphology of the compound during film formation, increasing the evaporation temperature of the compound, making it less likely to crack during high-temperature evaporation, and having good thermal stability, thereby increasing the service life of the device.

[0065] In addition, a triarylamine group with efficient transmission characteristics is connected to one side of the benzofluorene ring. The introduction of the triarylamine group increases the π-π conjugation effect within the molecule, making the π electron cloud distribution more uniform and the delocalization range wider, which helps to improve the fluorescence quantum efficiency. The addition of the triarylamine group can also enhance the stability of the molecule, thereby extending the service life of the material device. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 It is the hydrogen nuclear magnetic resonance spectrum of compound 1 provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0067] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0068] 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 value.

[0069] Example 1

[0070]

[0071] Raw material A-1 (1.0 eq, CAS number: 2566427-85-96), raw material B-1 (1.2 eq, CAS number: 500717-23-7), toluene and sodium tert-butoxide (3.0 eq) were added to the reaction flask. Tris(dibenzylideneacetone)dipalladium (0.02 eq) and tri-tert-butylphosphine (0.05 eq) were added under nitrogen. The temperature was raised to 120°C and stirred for reaction for 14 h. The reaction was detected by thin layer chromatography. After the reaction was completed, water and dichloromethane were added for extraction and separation. The organic phases were combined and concentrated. Compound 1 was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (volume ratio of 1:4) to obtain compound 1 (yield: 81.9%).

[0072] The obtained compound 1 was tested and analyzed, and the results were as follows:

[0073] HPLC purity: >99.8%.

[0074] Mass spectrometry test: The model is Waters XEVO TQD mass spectrometer, using ESI source.

[0075] Test value MS (ESI, m / Z): [M+H] + =735.60.

[0076] Elemental Analysis:

[0077] Calculated values: C, 91.39; H, 6.71; N, 1.90;

[0078] The test values ​​are: C, 91.11; H, 6.86; N, 2.04.

[0079] The H NMR spectrum of compound 1 is shown in Figure 1 shown.

[0080] Example 2

[0081]

[0082] Step 1 specifically includes the following processes:

[0083] At -78°C, raw material A-23 (1.3 eq, CAS number: 2142655-37-4) was added to a reaction bottle containing tetrahydrofuran, nitrogen was replaced 3 times, and the mixture was stirred for 20 minutes. n-Butyl lithium (1.3 eq) was slowly added to the reaction bottle and reacted for 2 hours. Raw material B-23 (1.0 eq, CAS number: 98750-22-2) was dissolved in tetrahydrofuran and then slowly dripped into the reaction bottle. After stirring evenly, refrigeration was stopped, and the mixture was heated to room temperature and continued to react for 6 hours. The reaction was detected by thin layer chromatography. After the reaction was completed, water and dichloromethane were added for separation and extraction. The organic phases were combined and concentrated. Intermediate 1 (yield: 72.5%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (volume ratio of 1:3).

[0084] Step 2 specifically includes the following processes:

[0085] A mixture of toluene (5.0 eq) and tetrahydrofuran (THF, 5.0 eq) was added to the reaction flask, and then intermediate 1 (1.0 eq) was added, and the mixture was stirred at room temperature until dissolved. Subsequently, methanesulfonic acid (5.0 eq) was added to the reaction flask, and the mixture was reacted for 30 min. The reaction was detected by thin layer chromatography. After the reaction was completed, water and dichloromethane were added for separation and extraction. The organic phases were combined and concentrated, and a mixed solution of dichloromethane and petroleum ether (volume ratio of 1:5) was used for purification by column chromatography to obtain intermediate 2 (yield: 77.3%).

[0086] Step 3 specifically includes the following processes:

[0087] Intermediate 2 (1.0 eq), raw material C-23 (1.1 eq, CAS number: 32228-99-2), toluene and sodium tert-butoxide (3.0 eq) were added to the reaction flask. Tris(dibenzylideneacetone)dipalladium (0.02 eq) and tri-tert-butylphosphine (0.05 eq) were added under nitrogen. The temperature was raised to 120°C and stirred for reaction for 12 h. The reaction was detected by thin layer chromatography. After the reaction was completed, water and dichloromethane were added for extraction and separation. The organic phases were combined and concentrated. Compound 23 (yield: 81.8%) was purified by column chromatography using a mixed solution of dichloromethane and petroleum ether (volume ratio of 1:5) to obtain compound 23 (yield: 81.8%).

[0088] The obtained compound 23 was tested and analyzed, and the results were as follows:

[0089] HPLC purity: >99.7%.

[0090] Mass spectrometry test: The model is Waters XEVO TQD mass spectrometer, using ESI source.

[0091] Test value MS (ESI, m / Z): [M+H] +=579.52.

[0092] Elemental Analysis:

[0093] Calculated values: C, 91.15; H, 6.43; N, 2.42;

[0094] The test values ​​are: C, 90.88; H, 6.59; N, 2.57.

[0095] 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-mentioned embodiments, so they are not listed one by one here.

[0096] Device Example 1: Preparation of red organic electroluminescent device

[0097] The structure of the prepared OLED device is: ITO anode / HIL / HTL / Prime / EML / HBL / ETL / EIL / cathode / CPL.

[0098] a. ITO anode: The ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 1500Å was cleaned in distilled water for 3 times, ultrasonically washed for 40 minutes, and then repeatedly cleaned with distilled water for 3 times, ultrasonically washed for 20 minutes. After washing, it was ultrasonically washed with methanol, acetone, and isopropanol in sequence (5 minutes each time), dried, and then transferred to a plasma cleaning machine for washing for 5 minutes. It was then sent to a vapor deposition machine, and the substrate was used as the anode, and other functional layers were deposited on it in sequence.

[0099] b. HIL (hole injection layer): Hole injection layer materials HT and P-dopant were vacuum evaporated at an evaporation rate of 1Å / s. The evaporation rate ratio of HT to P-dopant was 97:3, and the thickness was 10nm.

[0100] c. HTL (hole transport layer): 125 nm of HT was vacuum-deposited on the hole injection layer at a deposition rate of 1.5 Å / s as the hole transport layer.

[0101] d. Prime (luminescence auxiliary layer): 90 nm of the compound 1 provided in the above embodiment was vacuum-deposited on the hole transport layer at a deposition rate of 1.0 Å / s as a luminescence auxiliary layer.

[0102] e. EML (light-emitting layer): Then, on the above-mentioned light-emitting auxiliary layer, the host material (Host) and the dopant material (Dopant) with a thickness of 40nm are vacuum evaporated at a deposition rate of 1Å / s as the light-emitting layer, wherein the deposition rate ratio of Host and Dopant is 97:3.

[0103] f. HBL (hole blocking layer): A hole blocking layer HB with a thickness of 5 nm was vacuum-deposited at a deposition rate of 0.5 Å / s.

[0104] g. ETL (electron transport layer): ET and Liq with a thickness of 30 nm were vacuum evaporated at an evaporation rate of 1Å / s as the electron transport layer, where the evaporation rate ratio of ET to Liq was 50:50.

[0105] h. EIL (electron injection layer): 1 nm of Yb film was evaporated at a deposition rate of 0.5 Å / s to form an electron injection layer.

[0106] i. Cathode: 13 nm of magnesium and silver were evaporated at an evaporation rate ratio of 1 Å / s, and the evaporation rate ratio was 1:9 to obtain an OLED device.

[0107] j. CPL (light extraction layer): CPL with a thickness of 65 nm is vacuum-deposited on the cathode at a deposition rate of 1Å / s as a light extraction layer.

[0108] k. Then the vapor-deposited substrate is packaged. First, the cleaned cover is coated with UV glue using glue coating equipment, and then the coated cover is moved to the pressing section, the vapor-deposited substrate is placed on the upper end of the cover, and finally the substrate and cover are bonded by bonding equipment, and the UV glue is cured by light.

[0109] The structures of HT, P-dopant, Host, Dopant, HB, ET, and CPL used in the device embodiment 1 are as follows:

[0110]

[0111] Referring to the method provided in the above device embodiment 1, the corresponding compounds in Table 1 were selected to replace compound 1, and the luminescent auxiliary layer was evaporated to prepare the corresponding organic electroluminescent devices, which were respectively recorded as device embodiments 2 to 25.

[0112] Device Comparison Examples 1-8:

[0113] This comparative example provides an organic electroluminescent device. The only difference between the preparation method of the organic electroluminescent device and that of device embodiment 1 is that the organic electroluminescent device uses the existing comparative compound ah to replace the compound 1 in the device embodiment 1 as the light-emitting auxiliary material for evaporation. The chemical structure of the comparative compound ah is as follows:

[0114]

[0115] The driving voltage, luminous efficiency and life of the organic electroluminescent devices obtained in the above device embodiments 1 to 25 and device comparative examples 1 to 8 were characterized at a brightness of 6000 (nits). The test results are as follows

[0116] As shown in Table 1.

[0117] Table 1

[0118]

[0119]

[0120] It can be seen from Table 1 that, compared with the organic electroluminescent device prepared using the luminescent auxiliary material provided by the present invention and the organic electroluminescent device prepared using the comparative example compound, the luminescent efficiency and service life of the device are effectively improved while maintaining a lower driving voltage.

[0121]

[0122] Comparative compounds a and b and compounds 63 and 86 are parallel comparative examples, the difference between which is that the positions of the ring fusion of benzofluorene in comparative compounds a and b are 1.2 and 2.3 respectively (the definition of the ring fusion position: ), while the position of the benzene ring fusion in compounds 63 and 86 of the present invention is at the 3.4 position of fluorene, the structure is relatively more compact, and has higher stability under high temperature conditions.

[0123]

[0124] Comparative compounds c, d and compounds 4, 10 are parallel comparative examples, respectively. The difference is that the triarylamine N in comparative compounds c and d is connected to the benzene ring on the fluorene, while the triarylamine N in compounds 4 and 10 of the present invention is connected to the benzofluorene group and is on the side of the ring. The parent core structure is a benzofluorene structure, which has greater rigidity, effectively improves the thermal stability of the material, makes the material less likely to undergo structural changes during high-temperature evaporation, and effectively improves the service life of its device. And due to the introduction of additional benzene rings, a larger π-conjugated system is formed. This extended conjugation effect helps to reduce the band gap, thereby achieving emission of longer wavelengths (such as red light). The range of electron delocalization is expanded, the fluorescence quantum yield is improved, and the luminous efficiency of its material devices is effectively improved.

[0125]

[0126] Comparative compound e and compound 16 are parallel comparative examples, the difference between them is that in comparative compound e, the side chain of the triarylamine group is connected to a benzene-9-phenylcarbazole group, while in compound 16 of the present invention, the triarylamine group is connected to a benzene-9,9-dimethylfluorene group. Due to the steric hindrance effect of the methyl group, the aggregation quenching between molecules is reduced, showing a higher fluorescence quantum yield, and thus having a higher luminescence efficiency.

[0127]

[0128] Comparative compound f and compound 24 are parallel comparative examples, the difference between them is that in the compound 24 of the present invention, no other non-hydrogen substituents are connected to the adamantane, while a substituent (phenyl) is connected to the adamantane in the mother nucleus of comparative compound f. The introduction of the phenyl group does not have the effect of extending the conjugated system, but increases the overall molecular weight, affects the arrangement of the structure, and thus affects the stability of the material.

[0129]

[0130] Comparative compound g and compound 3 are parallel comparative examples, the difference between them is that in comparative compound g, the triarylamine group and the benzofluorene group are connected by a biphenyl group, while the triarylamine group in compound 3 of the present invention is directly connected to the benzofluorene group, the molecular structure is more compact, forming a more closely arranged structure, improving the thermal stability of the material, making the material less likely to crack under high-temperature evaporation, thereby enhancing the service life of the device.

[0131] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the luminescent auxiliary material and its preparation method and application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A luminescent auxiliary material, characterized in that: The general structural formula of the luminescence auxiliary material is Chemical Formula I: ； Ar1 and Ar2 are each independently selected from a substituted or unsubstituted C6-C30 aryl group, wherein the substituent in the substituted C6-C30 aryl group is selected from deuterium, an unsubstituted C1-C6 alkyl group, a C1-C6 alkyl group fully or partially substituted by deuterium, or a C6-C18 aryl group.

2. The luminescence auxiliary material according to claim 1, characterized in that: Ar1 and Ar2 are each independently selected from substituted or unsubstituted C6-C18 aryl groups, wherein the substituents in the substituted C6-C18 aryl groups are selected from deuterium, unsubstituted C1-C6 alkyl groups, C1-C6 alkyl groups fully or partially substituted with deuterium, or C6-C12 aryl groups.

3. The luminescence auxiliary material according to claim 1, characterized in that: Ar1 and Ar2 are each independently selected from any one of the following groups: ； The position of * is the attachment site of the group; R1-R9 are each independently selected from hydrogen, deuterium, unsubstituted C1-C6 alkyl, and C1-C6 alkyl fully or partially substituted by deuterium; n1 is independently selected from 0, 1, 2, 3, 4, 5; n2 and n5 are each independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9; n3 and n8 are each independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13; n4 and n6 are each independently selected from 0, 1, 2, 3, 4, 5, 6, 7; n7 and n9 are each independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11.

4. The luminescence auxiliary material according to claim 1, characterized in that: The luminescence auxiliary material is selected from the following compounds having any one of the structures of Chemical Formula I-1 to Chemical Formula I-6: ； The definitions of Ar1 and Ar2 are the same as those in Formula I.

5. The luminescence auxiliary material according to claim 1, characterized in that: The luminescence auxiliary material is any one of the following compounds: 。 6. The method for preparing the luminescence auxiliary material according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: (1) Raw material A reacts with raw material B to obtain intermediate 1; (2) Intermediate 1 is reacted in the presence of methanesulfonic acid to obtain intermediate 2; (3) The intermediate 2 reacts with the raw material C to obtain the luminescent auxiliary material shown in the chemical formula I; The reaction process of the preparation method is as follows: 。 7. The preparation method according to claim 6, characterized in that: The molar ratio of raw material A to raw material B in step (1) is 1.1-1.5:1; The reaction in step (1) is carried out in the presence of n-butyl lithium, wherein the molar ratio of n-butyl lithium to raw material B is 1.1-1.5:1; the n-butyl lithium is added to the reaction system at -78°C; The reaction in step (1) is carried out in an organic solvent, and the organic solvent is selected from tetrahydrofuran; The reaction temperature in step (1) is room temperature and the reaction time is 2-14 hours; In step (2), the molar ratio of the intermediate 1 to methanesulfonic acid is 3-10:1; The reaction in step (2) is carried out in an organic solvent selected from toluene and tetrahydrofuran; The reaction in step (2) is carried out at room temperature for 15-60 min. In step (3), the molar ratio of the intermediate 2 to the raw material C is 1: 1.0-1.3; The reaction in step (3) is carried out in the presence of an alkaline substance, wherein the alkaline substance is sodium tert-butoxide or potassium tert-butoxide, and the molar ratio of the alkaline substance to the raw material C is 2.0-4.0:1; The reaction in step (3) is carried out in the presence of a palladium catalyst, wherein the palladium catalyst is selected from tris(dibenzylideneacetone)dipalladium, tetrakis(triphenylphosphine)palladium, palladium dichloride, [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium, palladium acetate or bis(triphenylphosphine)palladium dichloride; the molar ratio of the palladium catalyst to the raw material C is 0.01-0.03:1; The reaction in step (3) is carried out in the presence of a phosphine ligand, wherein the phosphine ligand is selected from tri-tert-butyl phosphine, triethyl phosphine, trimethyl phosphine, triphenyl phosphine, potassium diphenylphosphine or di-tert-butyl phosphine chloride; the molar ratio of the phosphine ligand to the raw material C is 0.02-0.15:1; The reaction temperature in step (3) is 100-120°C and the reaction time is 2-18h.

8. A red organic light emitting device, characterized in that: The red organic light emitting device comprises a first electrode, a second electrode and at least one organic layer disposed between the first electrode and the second electrode, wherein the organic layer comprises the light emitting auxiliary material according to any one of claims 1 to 5.

9. The red organic light emitting device according to claim 8, characterized in that: The organic layer includes a luminescence-assisting layer, and the luminescence-assisting layer includes the luminescence-assisting material according to any one of claims 1 to 5.

10. The red organic light emitting device according to claim 8, characterized in that: The organic layer further includes 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 hole blocking layer, or a combination of at least two of them.

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