Organic light emitting diode material and preparation method and application thereof

Abstract

The present invention discloses an organic light-emitting diode material and a preparation method and application thereof. The organic light-emitting diode material has a chemical structure shown in formula V: #imgabs0# wherein: X is S, O, C(CH3)2 or SO, R1 is a triphenylamine group or a carbazole derivative group, and R2 is a methyl group; the preparation method comprises step d or step c~d or step b~c~d or step a~b~c~d in the synthesis route: #imgabs1# The organic light-emitting diode material provided by the present invention has a suitable triplet energy level, can match the frontier orbital energy level of the adjacent material constituting the existing organic light-emitting diode, excites blue-green fluorescence in a solid or liquid solution and improves the electroluminescence efficiency of the organic light-emitting diode, and at the same time, has excellent thermal stability, and can be used as a hole transport material or skeleton filling material or luminescent material of the organic light-emitting diode.

Description

Technical Field

[0001] The invention relates to an organic light emitting diode material and a preparation method and application thereof, belonging to the technical field of preparation and application of organic compounds. Background Art

[0002] Organic light-emitting diode (OLED) is a display device that uses organic compounds as its light-emitting material.

[0003] OLED display devices have the characteristics of self-luminescence and can be made of very thin organic material coatings and glass substrates. When current passes through, these organic material coatings will emit light, making the display screen made with OLED technology light and thin, with a large viewing angle, low operating voltage, and energy saving. It is convenient for making large-screen displays and foldable displays, and can also replace LCD or LED to become the new favorite in the lighting field.

[0004] With the development of technology, organic light-emitting diodes have gone through a development process from emitting ordinary fluorescence, emitting phosphorescence, to thermally activated delayed fluorescence and free radical luminescence. The internal quantum efficiency has also increased from the initial 25% to almost 100%, and the luminescent color has achieved full spectrum coverage, including red, green, blue and white light.

[0005] The structure of an OLED device in the prior art mainly includes an anode (anode), a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), a light-emitting layer (EML), a hole blocking layer (HBL), an electron transport layer (ETL), an electron injection layer (EIL) and a cathode (cathode). Among them, the hole transport material (HTM) in the hole transport layer (HTL) is one of the materials with the largest proportion in OLED devices.

[0006] Hole transport materials can reduce the energy barrier of hole injection, which is beneficial to hole transfer; in addition, hole transport materials also play a role in blocking electrons, which can limit the recombination area of ​​electrons and holes, thereby improving the utilization rate of carriers and improving the efficiency of electroluminescence.

[0007] Hole transport materials (HTM) used in the hole transport layer (HTL) of organic light-emitting diodes must meet certain photophysical properties, including:

[0008] The appropriate triplet energy level, i.e., the ability to prevent excitons from transferring from the light-emitting layer to the hole layer, is matched with the orbit with the highest energy level of occupied electrons, i.e., the highest occupied molecular orbital (HOMO), and the orbit with the lowest energy level of unoccupied electrons, i.e., the lowest unoccupied molecular orbital (LUMO), to meet the requirements of transferring holes and blocking electrons;

[0009] Good carrier mobility, so that holes and excitons can recombine in the light-emitting layer;

[0010] In addition, OLED devices in the prior art are mainly manufactured by thermal evaporation or solution method, which involves vacuum thermal evaporation and annealing treatment; and, since the thermal conductivity of the materials used to make organic light-emitting diodes is low, a large amount of Joule heat will be generated when the OLED device is working, thereby affecting the working efficiency and service life of the OLED device. Therefore, the thermal stability performance index of the hole transport material (HTM) is also crucial.

[0011] In order to meet the above-mentioned photophysical properties, the common strategy is to introduce triarylamine and carbazole groups into the molecular skeleton of the hole transport material (HTM) to construct the electron donating ability of the hole transport material (HTM) and realize the twisted configuration of the molecule to increase the rigidity of the molecule, for example:

[0012] The invention patent "Silane containing phenothiazine S-oxide or phenothiazine S, S-dioxide groups and its use in OLED" (application number: 200880022144.X) provides a silane containing phenothiazine S-oxide or phenothiazine S, S-dioxide groups, and an organic light-emitting diode containing the silane;

[0013] The invention patent "An organic semiconductor hole transport material" (application number: 201410194647.2) also provides an organic semiconductor hole transport material with a π-shaped aromatic heterocyclic amine as its molecular structure;

[0014] In addition, the invention patent application "Cross-linkable hole transport material for organic light-emitting devices" (application number: 200780025937.2) also discloses a cross-linkable compound that can be used to manufacture a hole transport material for an organic light-emitting device;

[0015] The hole transport material provided in the invention patent "Organic polymer, hole transport material containing the same, solar cell and light-emitting electronic device" (application number: 201810272328.7) is selected from any one of a thiophene group, a dithiophene group, a terthiophene group, a benzene ring group, a naphthalene group or a phenanthrene group, and the hole transport material also includes a side branch selected from any one of -CH2CH3, -NHCH3, -OCH3 or -SCH3.

[0016] However, by examining these existing technologies and existing materials, it can be found that the organic light-emitting diode materials provided by these technologies have relatively complex structures, are relatively difficult to prepare, and have certain deficiencies in their photophysical properties. Summary of the invention

[0017] In order to solve the deficiencies of the prior art, the embodiments of the present invention provide an organic light emitting diode material and a preparation method and application thereof, the purpose of which is:

[0018] Improve the thermal stability of organic light-emitting diodes, improve the spatial configuration of their constituent materials, obtain suitable triplet energy levels and frontier orbital energy levels to improve the electroluminescence efficiency of organic light-emitting diodes, and at the same time, simplify the preparation process of organic light-emitting diode materials, improve production efficiency, reduce production costs, and obtain better economic benefits.

[0019] To achieve the above objective, the present invention first provides an organic light emitting diode material.

[0020] The organic light emitting diode material has a chemical structure shown in Formula V:

[0021]

[0022] in:

[0023] X is S, O, C(CH3)2 or SO;

[0024] R1 is R 11 or R 12 The triphenylamine group shown: Or

[0025] R1 is R 13 , R 14 or R 15 The carbazole derivative groups shown are:

[0026] R2 is methyl.

[0027] Secondly, the present invention also provides a method for preparing the above organic light emitting diode material.

[0028] The preparation method of the present invention comprises step d or steps c-d or steps b-c-d or steps a-b-c-d in the following synthetic route:

[0029]

[0030] in:

[0031] Compound II is prepared by reacting any one of phenothiazine, phenothiazine S-oxide, phenoxazine or acridone in a mixed phase of tert-butyl chloride, aluminum chloride and dichloromethane via step a;

[0032] Compound III is prepared by dissolving the compound II in dichloromethane by dropwise addition of liquid bromine in step b;

[0033] Compound IV is prepared by reacting the compound III dissolved in a mixed solvent consisting of toluene, ethanol and water with a triphenylamine group or a carbazole derivative group compound represented by R1 through step c;

[0034] Compound V is prepared by reacting the compound IV dissolved in N,N-dimethylformamide with iodomethane in the presence of sodium hydride via step d.

[0035] Furthermore, in step a of the above preparation method:

[0036] The molar ratio of any one of the phenothiazine, phenothiazine S-oxide, phenoxazine or acridone to the tert-butyl chloride and the aluminum chloride is 1:(5-5.5):(2-2.5).

[0037] Further, the step a comprises:

[0038] Weigh a certain amount of any one of the phenothiazine, phenothiazine S-oxide, phenoxazine or acridone and put it into a reactor, then add aluminum chloride weighed according to the molar ratio in the above step a to the reactor, add dichloromethane as a solvent, cool and stir, and when the temperature of the reaction system drops below 0° C., add tert-butyl chloride weighed according to the molar ratio, stir, control the reaction temperature to maintain below 0° C., and carry out a substitution reaction;

[0039] After the above substitution reaction is completed, water is added to quench, and then sodium acetate is added for neutralization, and dichloromethane is added for extraction, and then the organic phase is separated and dried. After the organic phase is volatilized, a crude compound II is obtained, and the crude compound II is then purified and dried with cyclohexane to obtain the white compound II.

[0040] Furthermore, in step b of the preparation method:

[0041] The molar ratio of the compound II to the liquid bromine is 1:(5.5-6.5).

[0042] Further, the step b comprises:

[0043] Weigh a certain amount of the compound II and add it into a reactor, then add chloroform as a solvent, stir in an ice bath, and use argon to protect the reaction system;

[0044] Inject the liquid bromine weighed in the molar ratio described in the above step b into the above reaction system, stir at room temperature, and stir in an ice bath after the reaction is completed, and add excess hydrazine hydrate to quench the reaction, then add Na2CO3 solution for neutralization, extract the neutralized solution with dichloromethane, and wash with saturated brine;

[0045] The organic phase is separated from the reaction system after washing with water, filtered and dried, and the crude compound III is obtained after the organic phase is volatilized. The crude compound III is added to a chromatography column and eluted with a mixed solvent of dichloromethane and petroleum ether in a ratio of 1:10 by volume. After the eluate is dried, the compound III is obtained as a brownish solid.

[0046] Furthermore, in step c of the preparation method:

[0047] The compound III and the compound containing triphenylamine group R 11 or R 12 The compound or the compound containing the carbazole derivative group R 13 , R 14 or R 15 The molar ratio of the compound is 1:(2.5~3.0).

[0048] Further, the step c comprises:

[0049] Weigh a certain amount of the compound III and put it into the reactor, then add the compound containing triphenylamine group R weighed in the molar ratio described in step c above. 11 or R 12 The compound or the compound containing the carbazole derivative group R 13 , R 14 or R 15 A compound, adding a catalyst composed of potassium carbonate, palladium acetate and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, and then adding a solvent composed of toluene, ethanol and water, stirring and heating to reflux to carry out a substitution reaction, and using argon to protect the reaction system during the reaction;

[0050] After the reaction is completed, the crude compound IV is filtered and the solvent is removed to obtain the crude compound IV. The crude compound IV is added to a chromatography column and separated by gradient elution using a mixed solvent of dichloromethane and petroleum ether in a volume percentage of 1: (10-5). The eluate is collected and dried, and the mixed solvent is evaporated to obtain the compound IV as a white solid.

[0051] Further, the molar ratio of the catalyst is:

[0052] Potassium carbonate: palladium acetate: 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl = 1: (0.015-0.0018): (0.035-0.004).

[0053] Furthermore, in step d of the preparation method:

[0054] The molar ratio of the compound IV to the methyl iodide is 1:(2.5-5.0).

[0055] Further, the step d comprises:

[0056] Weigh a certain amount of the compound IV and add it to a reactor containing N,N-dimethylformamide solvent, then add sodium hydride, and under argon protection, add the iodomethane weighed according to the molar ratio described in the above step d to carry out a substitution reaction. After the reaction is completed, wash with water and filter to obtain a crude compound V;

[0057] The crude compound V was dissolved in dichloromethane, dried and filtered using anhydrous sodium sulfate, and after removing the solvent, it was added to a chromatography column and separated by gradient elution using a mixed solvent of dichloromethane and petroleum ether in a volume percentage of 1: (20-8). The eluate was dried over sodium sulfate, and the solvent of the dried eluate was removed to obtain the compound V as a white solid.

[0058] Furthermore, in the preparation method:

[0059] The chromatography column is a silica gel column, and the filling material of the silica gel column is 200-300 mesh silica gel.

[0060] In addition, the present invention also provides an application of the above organic light emitting diode material.

[0061] The application of the present invention is:

[0062] The organic light-emitting diode material having the chemical structure shown in formula V is evaporated in the hole transport layer of the organic light-emitting diode as the hole transport material of the organic light-emitting diode.

[0063] Compared with the prior art, the beneficial effects and significant improvements of the present invention are:

[0064] The organic light-emitting diode material provided by the present invention can excite blue-green fluorescence in a solid or liquid solution, which can prove that a suitable triplet energy level can be obtained through a relatively large conjugated system formed in the molecule, and the HOMO and LUMO energy levels thereof can match the frontier orbital energy levels of the adjacent materials constituting the existing organic light-emitting diodes, thereby improving the electroluminescence efficiency of the organic light-emitting diodes. At the same time, it also has high thermal stability, and can not only be used as a hole transport material for organic light-emitting diodes, but also can be used in organic light-emitting diodes as a skeleton filling material and a luminescent material, and is an ideal new material for preparing organic light-emitting diodes; and

[0065] The organic light-emitting diode material provided by the present invention has a simple molecular structure. Compared with the organic light-emitting diode material in the prior art, the preparation method thereof is simple and convenient, the product yield is high, the process is stable, and the production efficiency can be improved, the production cost can be reduced, and better economic benefits can be obtained in actual production. A new method is provided for the production of organic light-emitting diodes, which is of great value for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] In order to more clearly illustrate the technical solution of the present invention and the technical effects of implementing the present invention, the following briefly introduces the drawings used in the embodiments of the present invention.

[0067] Obviously:

[0068] The drawings described below are only drawings of some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work, but these other drawings also belong to the drawings required for use in the embodiments of the present invention.

[0069] Figure 1 It is an absorption and emission spectrum diagram of the hole transport material based on the phenothiazine group as the parent core in the organic light-emitting diode material provided by the present invention in a dichloromethane solvent, wherein the abscissa is the wavelength and the ordinate is the normalized intensity of the absorption light and the emission light of the detected hole transport material;

[0070] Figure 2 It is a low-temperature phosphorescence spectrum of a hole transport material based on a phenothiazine group as a parent core in an organic light-emitting diode material provided by the present invention in a dichloromethane solvent, wherein the abscissa is the wavelength and the ordinate is the normalized intensity of phosphorescence emission;

[0071] Figure 3 This is a glass transition temperature detection diagram of a hole transport material based on a phenothiazine group as a parent core in an organic light emitting diode material provided by the present invention. DETAILED DESCRIPTION

[0072] In order to make the purpose, technical solution, beneficial effects and significant progress of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings provided in the embodiments of the present invention. Obviously, all the described embodiments are only partial embodiments of the present invention, rather than all embodiments;

[0073] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0074] It should be noted that:

[0075] The terms "first", "second", etc. in the specification and claims of the present invention and the drawings of the embodiments of the present invention are only used to distinguish different objects, rather than to describe a specific order;

[0076] In addition, the term "comprise" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or apparatus comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes unlisted steps or units, or optionally also includes other steps or units inherent to these processes, methods, products or apparatus.

[0077] What needs to be understood is:

[0078] In the description of the embodiments of the present invention, some basic operation terms commonly used in the art are used, for example, "heating", "stirring", "mixing", "dissolving", "washing", "filtering" and "drying", etc. These terms should be understood in a broad sense. They can be conventional operations performed by various conventional equipment and instruments in the art, or they can be program-controlled operations, unmanned automatic operations, etc. performed by the latest equipment. Unless otherwise clearly defined, ordinary technicians in the art can understand the specific meanings of the above terms in the present invention according to the specific circumstances and adopt specific operation methods to achieve their operation purposes.

[0079] It should also be noted that:

[0080] The following specific embodiments may be combined with each other, and the same or similar concepts or processes therein may not be described in detail in some embodiments;

[0081] In addition, the raw materials, auxiliary materials, reaction equipment and facilities involved in the following specific embodiments are all commercially available.

[0082] The technical solution of the present invention is described in detail below with specific embodiments.

[0083] Example 1

[0084] This embodiment provides an organic light emitting diode material.

[0085] The organic light emitting diode material provided in this embodiment has a chemical structure shown in Formula V:

[0086]

[0087] in:

[0088] X is S, O, C(CH3)2 or SO;

[0089] R1 is R 11 or R 12 The triphenylamine group shown: Or

[0090] R1 is R 13 , R 14 or R 15 The carbazole derivative groups shown are:

[0091] R2 is methyl.

[0092] The organic light-emitting diode material provided in this embodiment has been experimentally proved to be able to excite blue-green fluorescence in a solid or liquid solution, and it can be seen from the structural formula and proved from experimental detection that a larger conjugated system can be formed in the molecule to obtain a suitable triplet energy level, and its HOMO and LUMO energy levels can match the frontier orbital energy levels of the adjacent materials constituting the existing organic light-emitting diodes, thereby improving the electroluminescence efficiency of the organic light-emitting diodes. At the same time, it also has high thermal stability, and can not only be used as a hole transport material for organic light-emitting diodes, but also can be used in organic light-emitting diodes as a skeleton filling material and a luminescent material, and is an ideal new material for preparing organic light-emitting diodes.

[0093] Example 2

[0094] This embodiment provides a method for preparing the organic light emitting diode material described in Embodiment 1.

[0095] The method for preparing the organic light-emitting diode material described in the above embodiment 1 provided in this embodiment includes step d or steps c-d or steps b-c-d or steps a-b-c-d in the following synthesis route:

[0096]

[0097] in:

[0098] Compound II is prepared by reacting any one of phenothiazine, phenothiazine S-oxide, phenoxazine or acridone in a mixed phase of tert-butyl chloride, aluminum chloride and dichloromethane via step a;

[0099] Compound III is prepared by dissolving compound II in dichloromethane by dropwise addition of liquid bromine in step b;

[0100] Compound IV is prepared by reacting compound III dissolved in a mixed solvent consisting of toluene, ethanol and water with a triphenylamine group or a carbazole derivative group compound represented by R1 through step c;

[0101] Compound V is prepared by dissolving compound IV in N,N-dimethylformamide and reacting with iodomethane in the presence of sodium hydride via step d.

[0102] Furthermore, in step a of the preparation method provided in this embodiment:

[0103] The molar ratio of any one of phenothiazine, phenothiazine S-oxide, phenoxazine or acridone to tert-butyl chloride and aluminum trichloride is 1:(5-5.5):(2-2.5); and

[0104] Step a specifically includes the following operations:

[0105] Weigh a certain amount of any one of phenothiazine, phenothiazine S-oxide, phenoxazine or acridone and put it into a reactor, then add aluminum chloride weighed in a molar ratio of any one of the above phenothiazine, phenothiazine S-oxide, phenoxazine or acridone to tert-butyl chloride and aluminum trichloride to the reactor, add dichloromethane (English abbreviation: DCM) as a solvent, cool and stir, when the temperature of the reaction system drops below 0°C, then add tert-butyl chloride weighed in the above molar ratio, stir, control the reaction temperature to maintain below 0°C, and carry out a substitution reaction;

[0106] After the above substitution reaction is completed, water is added to quench, and then sodium acetate is added for neutralization, and dichloromethane is added for extraction, and then the organic phase is separated and dried. After the organic phase is evaporated, a crude compound II is obtained, and the crude compound II is purified and dried with cyclohexane to obtain a white compound II.

[0107] Furthermore, in step b of the preparation method provided in this embodiment:

[0108] The molar ratio of compound II to liquid bromine is 1:(5.5-6.5); and

[0109] Step b includes the following operations:

[0110] Weigh a certain amount of compound II and add it into the reactor, then add chloroform as solvent, stir in an ice bath, and use argon to protect the reaction system;

[0111] Inject liquid bromine weighed in a molar ratio of compound II to liquid bromine of 1: (5.5-6.5) into the above reaction system, stir at room temperature, and after the reaction is completed, stir in an ice bath, add excess hydrazine hydrate to quench the reaction, then add Na2CO3 solution for neutralization, extract the neutralized solution with dichloromethane, and wash with saturated brine;

[0112] The organic phase was separated from the reaction system after washing, filtered and dried, and the crude compound III was obtained after the organic phase was volatilized. The crude compound III was added to a chromatography column and eluted with a mixed solvent of dichloromethane and petroleum ether in a ratio of 1:10 by volume. After the eluate was dried, a brownish solid compound III was obtained.

[0113] Furthermore, in step c of the preparation method provided in this embodiment:

[0114] Compound III and containing triphenylamine group R 11 or R 12 or a compound containing a carbazole derivative group R 13 , R 14 or R 15 The molar ratio of the compound is 1:(2.5-3.0); and

[0115] Step c includes the following operations:

[0116] Weigh a certain amount of compound III and put it into the reactor, then add the compound III and the mixture containing triphenylamine group R 11 or R 12 or a compound containing a carbazole derivative group R 13 , R 14 or R 15 The compound containing triphenylamine group R is weighed in a molar ratio of 1: (2.5-3.0) 11 or R 12 The compound also contains a carbazole derivative group R 13 , R 14 or R 15 A compound, adding a catalyst composed of potassium carbonate, palladium acetate and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, and then adding a solvent composed of toluene, ethanol and water, stirring and heating to reflux to carry out a substitution reaction, and using argon to protect the reaction system during the reaction;

[0117] After the reaction is completed, the crude compound IV is filtered and the solvent is removed to obtain the crude compound IV. The crude compound IV is added to a chromatography column and separated by gradient elution using a mixed solvent of dichloromethane and petroleum ether in a volume percentage of 1: (10-5). The eluate is collected and dried, and the mixed solvent is evaporated to obtain a white solid compound IV.

[0118] As an embodiment, in the preparation method provided in this embodiment, the molar ratio of the catalyst is:

[0119] Potassium carbonate: palladium acetate: 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl = 1: (0.015-0.0018): (0.035-0.004).

[0120] Furthermore, in step d of the preparation method provided in this embodiment:

[0121] The molar ratio of compound IV to methyl iodide is 1:(2.5-5.0); and

[0122] Step d includes the following specific operations:

[0123] Weigh a certain amount of compound IV and add it to a reactor containing N,N-dimethylformamide solvent, then add sodium hydride, and under argon protection, add iodomethane weighed in a molar ratio of compound IV to iodomethane of 1: (2.5-5.0) to carry out substitution reaction. After the reaction is completed, wash with water and filter to obtain a crude compound V;

[0124] The crude compound V was dissolved in dichloromethane, dried and filtered using anhydrous sodium sulfate, and after removing the solvent, it was added to a chromatography column and separated by gradient elution using a mixed solvent of dichloromethane and petroleum ether in a volume percentage of 1: (20-8). The eluate was dried over sodium sulfate, and the solvent of the dried eluate was removed to obtain compound V as a white solid.

[0125] As an optional embodiment, in the preparation method provided in this embodiment:

[0126] The chromatography column is a silica gel column, and the filling material of the silica gel column is 200-300 mesh silica gel.

[0127] From the above description, we can see that:

[0128] The method for preparing the organic light-emitting diode material provided in this embodiment has not been reported in the prior art. Compared with the method for preparing the organic light-emitting diode material in the prior art, the method provided in this embodiment is relatively simple, has a higher product yield, and a stable production process. In actual production, it can improve production efficiency, reduce production costs, and obtain better economic benefits. At the same time, the method provided in this embodiment provides a new idea and a new approach for the production of organic light-emitting diodes.

[0129] In order to further help understand the technical solution provided by the embodiment of the present invention, the specific operation process of the embodiment of the present invention and the effects that can be obtained, the preparation method is further explained below through a specific case of the synthesis and preparation of a phenothiazine organic light-emitting diode material.

[0130] A case of synthesis and preparation of phenothiazine organic light-emitting diode materials, including the following synthesis route:

[0131]

[0132] The synthetic preparation process specifically includes:

[0133] Step a1, preparation of compound II1:

[0134] Weigh 3 g of phenothiazine, namely Ⅰ1, and 4.32 g of AlCl3, add them into a 500 mL reaction bottle respectively, then add 200 mL of DCM as a solvent, cool and stir, when the temperature of the reaction system drops below 0°C, add 8.24 mL of tert-butyl chloride, stir for 5-10 min, and control the reaction temperature to maintain below 0°C for substitution reaction. After the reaction is completed, add water to quench, then add 7.38 g of sodium acetate for neutralization, and then add DCM for three extractions, each time using 50 mL of DCM, and then separate the organic phase and perform rotary evaporation to obtain a crude compound Ⅱ1. The crude compound Ⅱ1 is then purified and dried with cyclohexane to obtain 4.53 g of white compound Ⅱ1, namely 3,7-di-tert-butyl-10H-phenothiazine, and the weight percentage yield based on Ⅰ1 is 97.3%.

[0135] The NMR characterization data of compound Ⅱ1 are:

[0136] 1 H NMR (400 MHz, chloroform-d): δ 6.99 (s, 2H), 6.89 (d, J = 2.4 Hz, 2H), 6.62 (d, J = 8.4 Hz, 2H), 1.19 (s, 18H).

[0137] Step b1, preparation of compound III1:

[0138] Add 1 g of compound II1 into a 250 mL three-necked bottle, then add 100 mL of chloroform as solvent, stir in an ice bath, and use argon to protect the reaction system;

[0139] Inject 0.9 mL of liquid bromine into the above reaction system, stir at room temperature for 3 hours, then change to stirring in an ice bath, and add excess hydrazine hydrate to quench the reaction;

[0140] Then add 20 mL of sodium carbonate (Na2CO3) solution for neutralization, and extract the neutralized solution three times with DCM, each time with 50 mL of DCM, collect the extracts and wash with saturated salt;

[0141] The organic phase was separated from the reaction system after washing with water, filtered, and then the organic solvent was evaporated by rotary evaporation to obtain a crude compound III1. The crude compound III1 was added to a 200-300 mesh silica gel chromatography column and eluted with a mixed solvent of dichloromethane and petroleum ether in a ratio of 1:10 by volume. After the eluate was dried, 1.38 g of brownish solid compound III1 was obtained, namely 1,9-dibromo-3,7-di-tert-butyl-10H-phenothiazine, and the weight percentage yield based on II1 was 97.8%.

[0142] The NMR characterization data of compound Ⅲ1 are:

[0143] 1 H NMR (400 MHz, chloroform-d): δ 7.25 (s, 2H), 6.96 (s, 1H), 1.24 (s, 18H).

[0144] Step c1, preparation of compound IV1:

[0145] Weigh 100 mg of compound III1 and put it into a 100 mL single-mouth bottle, then add 135 mg of (9-phenyl-9H-carbazole-3-yl)boric acid and a catalyst composed of 88 mg of potassium carbonate, 2.4 mg of palladium acetate, and 12 mg of 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (English abbreviation: x-phos), and then add a solvent composed of 35 mL of toluene, 10 mL of ethanol and 5 mL of water, stir and heat to reflux to carry out the substitution reaction, and use argon to protect the reaction system during the reaction;

[0146] After reacting for 8 hours, the mixture was filtered and the solvent was removed by rotary evaporation to obtain a crude compound IV1. The crude compound IV1 was then added to a 200-300 mesh silica gel chromatography column and separated by gradient elution using a mixed solvent of dichloromethane and petroleum ether in a ratio of 1: (10-5) by volume. The eluate was collected and dried, and the mixed solvent was evaporated to obtain 143.4 mg of a white solid compound IV1, namely 1,9-bis(4-(9H-carbazole-9-yl)phenyl)-3,7-di-tert-butyl-10H-phenothiazine, with a weight percentage yield of 85.2% based on III1.

[0147] The nuclear magnetic resonance characterization data of compound IV1 are:

[0148] 1 H NMR (400MHz, chloroform-d) δ7.76 (d, J = 7.8Hz, 4H), 7.44-7.39 (m, 8H), 7.18 (s, 2H), 7.08 (d,J=8.2Hz,4H), 7.00(s,2H), 6.93(t,J=7.8Hz,4H), 6.80(m,4H), 1.31(s,18H);

[0149] The high-resolution mass spectrometry data of compound IV1 are:

[0150] HRMS(m / z): Detected: [M+H] + 794.3565, molecular formula C 56 H 47 N3S Requirements [M+H] + 794.3569.

[0151] Step d1, preparation of compound V1:

[0152] 100 mg of compound IV1 was added to a reactor containing 30 mL of N,N-dimethylformamide solvent (DMF), and then 12.1 mg of sodium hydride was added, and 0.078 mL of iodomethane was added under argon protection, and the mixture was stirred for 2 hours for substitution reaction. After the reaction was completed, 50 mL of water was added for washing, and then filtered to obtain a crude product of compound V1;

[0153] The crude compound V1 was dissolved in dichloromethane, dried and filtered with anhydrous sodium sulfate, and added to a 200-300 mesh silica gel chromatography column after removing the solvent. The column was eluted with an eluent of dichloromethane (DCM) and petroleum ether (PE) in a volume percentage of 1: (20-8). The eluent was dried with sodium sulfate, and the solvent in the dried eluent was removed to obtain 99.8 mg of white solid compound V1. The weight percentage yield based on IV1 was 98.1%.

[0154] The nuclear magnetic resonance characterization data of compound Ⅴ1 are:

[0155] 1 H NMR (400MHz, chloroform-d) δ7.54(d,J=6.8Hz,4H), 7.15(d,J=8.0Hz,4H), 7.01((d,J=8.0Hz,4H), 6.75(d, J=6.4Hz,2H), 6.62(d,J=8.0Hz,4H), 6.55(d,J=6.4Hz,2H), 6.51(t,J=8.0Hz,2H), 6.29(t,J=7.6Hz 4H), 2.16(s,3H), 0.80(s,18H);

[0156] 13C NMR (151 MHz, chloroform-d) δ 147.7, 142.3, 140.4, 140.1, 136.5, 135.5, 131.7, 130.7, 127.8, 126.2, 125.5, 123.5, 123.3, 120.0, 119.7, 109.2, 44.2, 34.4, 31.3.

[0157] The high-resolution mass spectrometry characterization data of compound Ⅴ1 are:

[0158] HRMS(m / z): [M+H] detected + 808.3741, molecular formula C 57 H 49 N3S Requirements [M+H] + 808.3725.

[0159] The above case gives a synthesis process of a phenothiazine organic light-emitting diode material compound V1, where: R1 is R 14 , R2 is methyl.

[0160] In fact, experiments have shown that:

[0161] When the starting material Ⅰ is Ⅰ1, i.e., phenothiazine, R1 is respectively R 11 , R 12 , R 13 or R 15 , when R2 is methyl, by adopting the same synthesis route and preparation operation process as the above case, and adopting the material molar ratio determined in each step of the synthesis route, a phenothiazine series organic light-emitting diode material product corresponding to the chemical structure shown in formula V can be obtained, and the obtained products not only have similar physical and chemical properties, but also the weight percentage yield of each product in the preparation process is basically the same as the weight percentage yield of the product obtained in each step of the above case;

[0162] Please refer to Table 1 for the material ratios and weight percentage yields of some phenothiazine series organic light-emitting diode materials in the synthesis process; and

[0163] When X in the starting material I is S, O, C(CH3)2 or SO, R1 is R 11 , R 12 , R 13 , R 14 , R 15, when R2 is methyl, the same synthetic route and preparation process as in the above case are adopted, and in each step, the ratio of the reaction materials is controlled within the range of the material molar ratio determined by the above preparation method, then a series of organic light-emitting diode materials based on phenothiazine, phenothiazine S-oxide, phenoxazine and acridone as the basic structure corresponding to the chemical structure shown in formula V can be obtained, and the weight percentage yield of the obtained product is basically the same as the weight percentage yield of the product obtained in each step of the above case;

[0164] Table 2 records the material ratios and weight percentage yields of the series of organic light-emitting diode materials based on phenothiazine S-oxide, phenoxazine and acridone in the synthesis process;

[0165] Tables 3, 4 and 5 respectively record the material ratios and weight percentage yield data in steps c and d of the synthesis process of a series of organic light-emitting diode materials based on phenothiazine S-oxide, phenoxazine and acridone as the basic structure.

[0166] Table 1. Material ratio and yield of some phenothiazine series organic light-emitting diode materials:

[0167]

[0168] Table 2. Material ratios and weight percentage yields of a series of organic light-emitting diode materials based on phenothiazine S-oxide, phenoxazine and acridone in the synthesis process:

[0169]

[0170] Table 3. Material ratios and weight percentage yields in steps c and d of the synthesis process of some series of organic light-emitting diode materials based on phenothiazine S-oxide:

[0171]

[0172] Table 4. Material ratios and weight percentage yields in steps c and d of the synthesis process of some series of organic light-emitting diode materials based on phenoxazine as the basic structure:

[0173]

[0174] Table 5. Material ratios and weight percentage yields in steps c and d of the synthesis process of some series of organic light-emitting diode materials based on acridone as the basic structure:

[0175]

[0176] From the above cases and the data listed in Tables 1 to 5, we can see that:

[0177] The preparation method of the organic light-emitting diode material provided in this embodiment is relatively simple and has a stable process compared to the existing organic light-emitting diode materials in the prior art. In actual production, it can improve product yield and production efficiency, reduce production costs, and obtain better economic benefits. At the same time, it provides new materials and new synthesis methods for the production of organic light-emitting diodes.

[0178] Example 3

[0179] This embodiment provides an application of the organic light emitting diode material described in Embodiment 1.

[0180] The compound of Example 1 having a chemical structure shown in Formula V obtained by the preparation method provided in Example 2, wherein the X group is S, O, C(CH3)2 or SO, and the R1 group is R 11 or R 12 The triphenylamine group shown is also R 13 , R 14 or R 15 Any one of the organic light-emitting diode materials wherein R2 is a methyl group is filled or evaporated in the hole transport layer (HTL), electron blocking layer (EBL) or light-emitting layer (EML) of an OLED device comprising an anode (anode), a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), a light-emitting layer (EML), a hole blocking layer (HBL), an electron transport layer (ETL), an electron injection layer (EIL) and a cathode (HIL) as a skeleton filler or a light-emitting substance in each layer; or

[0181] The compound of Example 1 having a chemical structure shown in Formula V obtained by the preparation method provided in Example 2, wherein the X group is S, O, C(CH3)2 or SO, and the R1 group is R 11 or R 12 The triphenylamine group shown is also R 13 , R 14 or R 15 The carbazole derivative group shown, any one of the organic light-emitting diode materials in which R2 is methyl, is filled or evaporated in the hole transport layer (HTL) of the above-mentioned OLED device as the hole transport material (HTM) therein).

[0182] From the above description, we can see that:

[0183] The organic light emitting diode material provided in this embodiment can not only be used as a hole transport material of an organic light emitting diode, but also can be used in various layers of an organic light emitting diode as a skeleton filling material and a light emitting material, and is a new ideal material for manufacturing an organic light emitting diode.

[0184] Effect Example 1

[0185] This effect example is used to demonstrate the photophysical properties of the organic light emitting diode material provided by the embodiment of the present invention.

[0186] Take the compound V1 prepared in the synthesis preparation case of a phenothiazine organic light-emitting diode material in the above embodiment 2, and take R1 as R according to the method of the synthesis preparation case of a phenothiazine organic light-emitting diode material in the above embodiment 2. 15 Compound V2 prepared by the method of synthesizing a phenothiazine organic light-emitting diode material in Example 2 above, wherein R1 is R 12 The absorbance and emission spectrum of the compound V3 prepared at the same time were measured under the same conditions, as well as the low-temperature phosphorescence emission spectrum. For specific absorption and emission spectrum tests and low-temperature phosphorescence emission spectrum, see Figure 1 Absorption and emission spectra of the hole transport material based on the phenothiazine group as the parent core in the organic light-emitting diode material provided by the present invention in dichloromethane solvent, and Figure 2 A low-temperature phosphorescence spectrum of a hole transport material based on a phenothiazine group as a parent core in an organic light-emitting diode material provided by the present invention in a 2-methyltetrahydrofuran solvent.

[0187] according to Figure 1 As shown, it can be seen that:

[0188] 1) Compounds V1 and V2 are very close in absorption, and their respective maximum absorption peaks appear at 338nm and 335nm, respectively, which indicates that V1 and V2 have similar n-π* transitions; and their π-π* transition absorption peaks are 294nm and 273nm, respectively, indicating that V1 and V2 also have similar π-π* transitions; while the absorption peak of V3 only appears at 310nm, proving that it has n-π* transitions, compared with R 14 , R 15 The products V1 and V2, in which R1 is a phenylcarbazole group, have a blue-shifted absorption of nearly 30 nm, indicating that their charge separation is relatively small;

[0189] 2) From the edges of the absorption peaks of compounds V1, V2 and V3, we can obtain λ onset The wavelength value can be used to calculate the band gap (E g ) value, calculated E gThe values ​​are 3.26 eV, 3.14 eV and 3.20 eV, respectively, which indicates that compounds V1, V2 and V3 may have good electron blocking ability and hole transport ability;

[0190] In addition, compounds Ⅴ1, Ⅴ2 and Ⅴ3 all emit single emission with roughly the same emission wavelength, which are 474nm, 455nm and 465nm, respectively, and the excited singlet energy levels are 3.18eV, 3.35eV and 3.07eV, respectively. Since the low singlet energy level is conducive to the migration of carriers, the above three compounds have good carrier migration performance.

[0191] according to Figure 2 As shown, it can be seen that:

[0192] The phosphorescence spectrum is a multiple emission, generated by different triplet emission energy levels. The first phosphorescence emission peaks of compounds V1, V2 and V3 are at 494nm, 490nm and 470nm, respectively. T =1241 / λ, the triplet energy levels (E T ) are 2.51eV, 2.53eV and 2.64eV respectively;

[0193] The above data indicate that compounds V1, V2 and V3 have good triplet energy levels as hole transport materials (HTM) for organic light-emitting diodes.

[0194] Although this specification only provides in this effect embodiment 1 Figure 1 The absorption and emission spectra of compounds V1, V2 and V3 shown in FIG. Figure 2 The low-temperature phosphorescence spectrum shown in the figure is not a good example. However, according to the principle of similarity and related experiments, it can be obtained that the series of organic light-emitting diode materials with the chemical structure shown in Formula V provided by the present invention have similar photophysical properties as compounds V1, V2 and V3, can meet the needs of being used as hole transport materials or skeleton filling materials and luminescent materials for organic light-emitting diodes, and are a new ideal material for preparing organic light-emitting diodes.

[0195] Effect Example 2

[0196] This effect example is used to demonstrate the thermal stability of the organic light emitting diode material provided by the embodiment of the present invention.

[0197] The glass transition temperatures of compounds V1, V2 and V3 in the above-mentioned Example 1 were measured using a differential scanning calorimeter under the same conditions. The relevant results are shown in Figure 3The glass transition temperature detection graph of the hole transport material based on the phenothiazine group as the mother core in the organic light emitting diode material provided by the present invention is shown in FIG.

[0198] from Figure 3 It can be seen that:

[0199] The glass transition temperatures of compounds V1, V2 and V3 are 167°C, 112°C and 144°C, respectively.

[0200] As hole transport materials or skeleton filling materials and luminescent materials of organic light-emitting diodes, degradation caused by high temperatures generated by their own luminescence should be avoided; at the same time, since the preparation of existing organic light-emitting diodes mainly adopts thermal evaporation and solution methods, vacuum thermal evaporation and annealing treatment are involved. Therefore, the organic compounds in the organic light-emitting diodes are required to have good thermal stability, among which the glass transition temperature is an important criterion for judging thermal stability performance.

[0201] from Figure 3 It can be seen that compounds Ⅴ1, Ⅴ2 and Ⅴ3 all have relatively high glass transition temperatures, proving that they have good thermal stability and can meet the requirements for use of organic light-emitting diodes.

[0202] Although only one embodiment of the present invention provides Figure 3 The glass transition temperature detection data of compounds V1, V2 and V3 shown in the figure are as follows. However, according to the principle of similarity and related experiments, it can be obtained that the series of organic light-emitting diode materials having the chemical structure shown in formula V provided by the present invention have similar glass transition temperatures as compounds V1, V2 and V3, that is, similar thermal stability, can meet the use requirements of organic light-emitting diodes, and are a new ideal material for preparing organic light-emitting diodes.

[0203] In summary, we can see that:

[0204] The organic light-emitting diode material provided by the embodiment of the present invention can obtain a suitable triplet energy level through the larger conjugated system formed by its molecular internal structure, and its HOMO and LUMO energy levels can match the frontier orbital energy levels of the adjacent materials constituting the existing organic light-emitting diode, so that it can excite blue-green fluorescence in a solid or liquid solution and improve the electroluminescence efficiency of the organic light-emitting diode;

[0205] At the same time, since the compound V provided in the embodiment of the present invention has excellent thermal stability, and thanks to its molecular configuration, it can form a twisted spatial structure and make its structural unit have good rigidity, which is conducive to evaporation preparation and has good resistance to the heat generated by the light emission of the organic light-emitting diode, it can improve the life and luminous efficiency of the organic light-emitting diode. It can not only be used as a hole transport material for the organic light-emitting diode, but also can be used in the organic light-emitting diode as a skeleton filling material and a luminescent material, and is an ideal material for preparing an organic light-emitting diode; and

[0206] The organic light-emitting diode material provided in the embodiment of the present invention has a simple molecular structure. Compared with the organic light-emitting diode material in the prior art, the preparation method thereof is simple and convenient, the product yield is high, and the process is stable. In actual production, the production efficiency can be improved, the production cost can be reduced, and better economic benefits can be obtained. At the same time, new materials and methods are provided for the production of organic light-emitting diodes. Therefore, the material has great promotion and application value.

[0207] In the description of the above manual:

[0208] The terms "this embodiment", "an embodiment of the present invention", "as shown in", "further", etc., mean that the specific features, structures, materials or characteristics described in the embodiment or example are included in at least one embodiment or example of the present invention;

[0209] In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example, and the specific features, structures, materials or characteristics described may be combined or combined in any one or more embodiments or examples in a suitable manner;

[0210] In addition, under the premise that no contradiction occurs, a person of ordinary skill in the art may combine or combine different embodiments or examples and features of different embodiments or examples described in this specification.

[0211] Finally, it should be noted that:

[0212] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. The non-essential improvements, adjustments or replacements made by those skilled in the art based on the contents of this specification are all within the scope of protection required by the present invention.

Claims

1. An organic light emitting diode material, characterized in that: The organic light emitting diode material has a chemical structure shown in Formula V: in: X is S, O, C(CH3)2 or SO; R1 is R 11 or R 12 The triphenylamine group shown: Or R1 is R 13 , R 14 or R 15 The carbazole derivative groups shown R2 is methyl.

2. A method for preparing the organic light emitting diode material according to claim 1, characterized in that: The preparation method comprises step d or steps c-d or steps b-c-d or steps a-b-c-d in the following synthetic route: in: Compound II is prepared by reacting any one of phenothiazine, phenothiazine S-oxide, phenoxazine or acridone in a mixed phase of tert-butyl chloride, aluminum chloride and dichloromethane via step a; Compound III is prepared by dissolving the compound II in dichloromethane by dropwise addition of liquid bromine in step b; Compound IV is prepared by reacting the compound III dissolved in a mixed solvent consisting of toluene, ethanol and water with a triphenylamine group or a carbazole derivative group compound represented by R1 through step c, wherein: The compound III contains a triphenylamine group R 11 or R 12 or a compound containing a carbazole derivative group R 13 , R 14 or R 15 The molar ratio of the compound is 1:(2.5-3.0); Weigh a certain amount of the compound III and put it into the reactor, then add the triphenylamine group R 11 or R 12 The compound also contains a carbazole derivative group R 13 , R 14 , R 15 or R 16 A compound, adding a catalyst composed of potassium carbonate, palladium acetate and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, and then adding a solvent composed of toluene, ethanol and water, stirring and heating to reflux to carry out a substitution reaction, and using argon to protect the reaction system during the reaction; After the reaction is completed, the crude compound IV is filtered and the solvent is removed to obtain the crude compound IV. The crude compound IV is added to a chromatography column and separated by gradient elution using a mixed solvent of dichloromethane and petroleum ether in a volume percentage of 1: (10-5). The eluate is collected and dried, and the mixed solvent is evaporated to obtain the compound IV as a white solid; Compound V is prepared by dissolving the compound IV in N,N-dimethylformamide and reacting it with iodomethane in the presence of sodium hydride through step d.

3. The preparation method according to claim 2, characterized in that: In the step a: The molar ratio of any one of the phenothiazine, phenothiazine S-oxide, phenoxazine or acridone to the tert-butyl chloride and the aluminum chloride is 1:(5-5.5):(2-2.5).

4. The preparation method according to claim 3, characterized in that: The step a comprises: Weigh a certain amount of any one of the phenothiazine, phenothiazine S-oxide, phenoxazine or acridone and put it into a reactor, then add aluminum chloride weighed according to the molar ratio of claim 3 to the reactor, add dichloromethane as a solvent, cool and stir, and when the temperature of the reaction system drops below 0°C, add tert-butyl chloride weighed according to the molar ratio of claim 3, stir, control the reaction temperature to maintain below 0°C, and carry out substitution reaction; After the above substitution reaction is completed, water is added to quench, and then sodium acetate is added for neutralization, and dichloromethane is added for extraction, and then the organic phase is separated and dried. After the organic phase is volatilized, a crude compound II is obtained, and the crude compound II is then purified and dried with cyclohexane to obtain the white compound II.

5. The preparation method according to claim 2, characterized in that: In the step b: The molar ratio of the compound II to the liquid bromine is 1:(5.5-6.5).

6. The preparation method according to claim 5, characterized in that: The step b comprises: Weigh a certain amount of the compound II and add it into a reactor, then add chloroform as a solvent, stir in an ice bath, and use argon to protect the reaction system; Inject the liquid bromine weighed in the molar ratio according to claim 5 into the reaction system, stir at room temperature, stir in an ice bath after the reaction is completed, add excess hydrazine hydrate to quench the reaction, then add Na2CO3 solution for neutralization, extract the neutralized solution with dichloromethane, and wash with saturated brine; The organic phase is separated from the reaction system after washing with water, filtered and dried, and a crude compound III is obtained after the organic solvent evaporates. The crude compound III is added to a chromatography column and eluted with a mixed solvent of dichloromethane and petroleum ether in a ratio of 1:10 by volume. After the eluate is dried, a brownish solid compound III is obtained.

7. The preparation method according to claim 2, characterized in that: The molar ratio of the catalyst is: Potassium carbonate: palladium acetate: 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl = 1: (0.015-0.0018): (0.035-0.004).

8. The preparation method according to claim 2, characterized in that: In the step d: The molar ratio of the compound IV to the methyl iodide is 1:(2.5-5.0).

9. The preparation method according to claim 8, characterized in that: The step d comprises: Weigh a certain amount of the compound IV and add it to a reactor containing N,N-dimethylformamide solvent, then add sodium hydride, and under argon protection, add the iodomethane weighed according to the molar ratio of claim 8 to carry out a substitution reaction. After the reaction is completed, wash with water and filter to obtain a crude compound V; The crude compound V was dissolved in dichloromethane, dried and filtered using anhydrous sodium sulfate, and after removing the solvent, it was added to a chromatography column and separated by gradient elution using a mixed solvent of dichloromethane and petroleum ether in a volume percentage of 1: (20-8). The eluate was dried over sodium sulfate, and the solvent in the dried eluate was removed to obtain the compound V as a white solid.

10. The preparation method according to any one of claims 2, 6 or 9, characterized in that: The chromatography column is a silica gel column, and the filling material of the silica gel column is 200-300 mesh silica gel.

11. A use of the organic light emitting diode material according to claim 1, characterized in that: The application is to evaporate the organic light-emitting diode material having the chemical structure shown in formula V into the hole transport layer of the organic light-emitting diode as the hole transport material of the organic light-emitting diode.

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