A triazine-based condensed ring electron transport material containing an aromatic group

Abstract

The present invention provides a triazine-based fused-ring electron transport material containing an aromatic group, having the structural formula: Ar1 and Ar2 are deuterium-containing or non-deuterium-containing aromatic groups with 6 to 18 ring carbon atoms. Phenanthrene and carbazole are introduced as substituents on the triazine to enhance the material's conjugated system, improve the compound's electron transport properties and thermal stability, and have broad application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of organic synthesis, and in particular to a triazine-based condensed ring electron transport material containing an aromatic group. Background Art

[0002] OLEDs were originally invented and proposed by Eastman Kodak. Tang and Van Slyke reported a bilayer organic electroluminescent device consisting of an arylamine hole transport layer and a tris-8-hydroxyquinoline-aluminum layer as both the electron transport and light-emitting layers. OLEDs have attracted considerable attention due to their fast reaction rates, light weight, thinness, wide viewing angles, high brightness, high contrast, no need for a backlight, and low energy consumption.

[0003] Existing organic electroluminescent devices generally consist of, from top to bottom, a cathode, an electron injection layer, an electron transport layer, an organic light-emitting layer, a hole transport layer, a hole injection layer, an anode, and a substrate. Improving the efficiency of organic electroluminescent devices primarily relies on maximizing the probability of exciton formation within the organic light-emitting layer. The material of the electron transport layer, adjacent to the organic light-emitting layer, plays a crucial role in the luminous efficiency of organic electroluminescent devices.

[0004] In OLED materials, the mobility of electrons is generally 2-3 orders of magnitude lower than that of holes. Therefore, the number of holes in OLEDs is far greater than the number of electrons. Therefore, the development of efficient electron transport materials is very important to improve the efficiency of OLEDs. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a triazine-based electron transport material containing an aromatic fused ring. The electron transport material provided by the present invention has better electron transport properties and stability.

[0006] The present invention provides a triazine-based condensed ring electron transport material containing an aromatic group, the structural formula of which is:

[0007]

[0008] Furthermore, Ar1 and Ar2 are deuterium-containing or non-deuterium-containing aromatic groups with 6 to 18 ring carbon atoms. The present invention introduces groups such as carbazole and triazine to enhance the electronegativity of the material and improve the electron transport properties of the compound. Phenanthrene is used to connect the enhanced conjugated system of the material and improve the thermal stability of the compound. The present invention provides organic electroluminescent compounds with high thermal stability, film-forming properties, and strong electron mobility.

[0009] Furthermore, the structural formula of Ar1 and Ar2 is

[0010] One or more of .

[0011] Furthermore, the structural formula of the triazine-based aromatic fused ring electron transport material can be:

[0012]

[0013]

[0014] Furthermore, the main structure of the triazine-based aromatic fused ring electron transport material is compound 1.

[0015] Furthermore, the structural formula of the compound 1 is:

[0016] Furthermore, the preparation method of compound 1 is:

[0017] S1: Carbazole (1.5 eq), sodium tert-butoxide (2 eq), a metal catalyst (0.005 eq), a metal catalyst ligand (0.01 eq) and toluene (12 v / w) were purged with nitrogen to replace the air and then refluxed for reaction. After the reaction was completed, toluene was added for crystallization and purification to obtain S1;

[0018] S2: The S1 was placed in a reactor, and p-chlorophenylboric acid (1.2 eq), potassium carbonate (2.0 eq), palladium acetate (0.005 eq), toluene (7 v / w), ethanol (1 v / w) and deionized water (3 v / w) were added. Nitrogen was introduced to replace the air and the reaction was refluxed. After the reaction was completed, the toluene was crystallized and purified to obtain S2;

[0019] S3: The S2 was placed in a reactor, and diboric acid pinacol ester (1.2 eq), potassium acetate (1.5 eq), a metal catalyst (0.005 eq), a metal catalyst ligand (0.01 eq) and 1,4-dioxane (8 v / w) were added. Nitrogen was introduced to replace the air and then reflux reaction was carried out. After the reaction was completed, purification was performed to obtain the compound 1.

[0020] Furthermore, the metal catalyst is Pd2(dba)3.

[0021] Furthermore, the catalyst ligand of the step is X-phos.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. Introducing phenanthrene and carbazole into the substituents of triazine to strengthen the conjugated system of the material, improve the electron transport performance and thermal stability of the compound. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0025] Reagent Description:

[0026] Carbazole (CAS: 86-74-8), 98%, Anage (Shanghai) Pharmaceutical Chemical Co., Ltd.; 2,7-Dibromophenanthrene (CAS: 62325-30-8), 98%, p-Chlorophenylboric acid (CAS: 1679-18-1), 98%, Cyanuric chloride (CAS: 108-77-0), 99%, Shanghai MacLean Biochemical Technology Co., Ltd.

[0027] Example 1

[0028] Preparation of ET9:

[0029] S1: 300 mmol of 2,7-dibromophenanthrene, 450 mmol of carbazole, 600 mmol of sodium tert-butoxide, 1.5 mmol of Pd2(dba)3, and 3 mmol of X-phos were added to a reaction flask, and the atmosphere was replaced with nitrogen. The reaction was refluxed for 2 h. The carbazole portion remained, and the reaction was stopped. 500 ml of water was added and neutralized with dilute acid until neutral. The liquid was separated, and the aqueous phase was extracted with 500 ml of toluene, washed with water, dried over anhydrous sodium sulfate, and filled with silica gel and passed through a column. The column liquid was concentrated to about 200 ml, and 300 ml of ethanol was added for crystallization for 1 h. The mixture was filtered and dried. The resulting solid was recrystallized from toluene and dried to obtain 77.2 g of off-white solid S1;

[0030] S2: 150 mmol of S1, 160 mmol of p-chlorophenylboronic acid, 300 mmol of potassium carbonate, 1.5 mmol of palladium acetate were added to a reaction flask, and 450 ml of toluene, 65 ml of ethanol, and 190 ml of water were added. The atmosphere was replaced with nitrogen and refluxed for 2 h. After the reaction of the raw materials was completed, the reaction was stopped, 200 ml of water was added each time, the mixture was washed with water three times, dried over anhydrous sodium sulfate, filled with silica gel and passed through a column, concentrated to 130 ml, and crystallized with 130 ml of ethanol for 0.5 h. The mixture was filtered and dried. The resulting solid was recrystallized from toluene and dried to obtain 57.9 g of off-white solid S2;

[0031] S3: Add 100 mmol of S2, 120 mmol of diboronic acid pinacol ester, 200 mmol of potassium acetate, 0.5 mmol of Pd2(dba)3, 1 mmol of X-phos, and 450 mL of 1,4-dioxane to the reaction flask. Replace the atmosphere with nitrogen and reflux for 4 h. Once the reaction is complete, stop the reaction. Concentrate to almost dryness, add 900 mL of dichloromethane, dissolve in 0.5 L of water, separate the liquids, wash the organic phase with water until neutral, dry with anhydrous sodium sulfate, fill with silica gel and pass through a column, concentrate until a large amount of solid precipitates, add 200 mL of petroleum ether and crystallize for 0.5 h, filter, and dry to obtain 43.6 g of off-white solid compound 1.

[0032] S4: Prepare phenylmagnesium bromide with 400mmol of bromobenzene, 405mmol of magnesium chips, and 640mL of tetrahydrofuran, and store it in an ice bath at 5°C. Add 400mmol of cyanuric chloride and 300ml of tetrahydrofuran to the reaction flask, cool it to 5°C, and slowly add the prepared deuterated phenylmagnesium bromide solution dropwise to the reaction system at around 30°C. After the addition is complete, raise the temperature to 30°C and react for 2h. Stop the reaction, slowly pour the reaction solution into dilute hydrochloric acid to quench it, extract it with tetrahydrofuran, wash it with saturated brine, concentrate it to dryness, add 1.3L of toluene to dissolve it and pass it through a column, concentrate it to 130ml and crystallize it for 1h, filter and dry it, and recrystallize the obtained solid from toluene to obtain 63.2g of off-white solid S4;

[0033] S5: Prepare a Grignard solution with 200 mmol of 4-bromopyridine, 205 mmol of magnesium chips, and 320 mL of tetrahydrofuran, and store it in an ice bath at 5°C. Add 280 mmol of S4 and 160 ml of tetrahydrofuran to the reaction flask, cool it to 5°C, and slowly add the prepared Grignard solution dropwise to the reaction system at around 30°C. After the addition is complete, raise the temperature to 30°C and react for 2 hours. Stop the reaction, slowly pour the reaction solution into dilute hydrochloric acid to quench it, extract it with tetrahydrofuran, wash it with saturated brine, concentrate it to dryness, add 1.2 L of toluene to dissolve it in a column, concentrate it to 120 ml and crystallize it for 1 hour, filter and dry it, and continue to recrystallize the obtained solid from toluene to obtain 25.6 g of off-white solid S5;

[0034] S6: Add 70 mmol of S5, 80 mmol of compound 1, 140 mmol of potassium carbonate, 0.35 mmol of palladium acetate to the reaction flask, add 140 ml of toluene, 20 ml of ethanol, 60 ml of water, replace with nitrogen, reflux for 16 hours, a small amount of S5 remains, stop the reaction, cool the reactant to room temperature, add water, filter, wash with water, and slurry the obtained solid with 100 ml of ethanol, filter and dry. Heat and dissolve 1 L of toluene, fill with silica gel and pass through a column. The column liquid is concentrated to 80 ml, crystallize for 1 hour, filter and dry to obtain 14.1 g of off-white solid ET9.

[0035] ET9 was tested by LCMS and the data obtained were as follows:

[0036] ESI-MS: C46H29N5, standard molecular weight 651.76, measured result 652.25 [M+H].

[0037] Example 2:

[0038] Preparation of ET10:

[0039] S1: 300 mmol of 2,7-dibromophenanthrene, 450 mmol of carbazole, 600 mmol of sodium tert-butoxide, 1.5 mmol of Pd2(dba)3, and 3 mmol of X-phos were added to a reaction flask, and the atmosphere was replaced with nitrogen. The reaction was refluxed for 2 h. The carbazole portion remained, and the reaction was stopped. 500 ml of water was added and neutralized with dilute acid until neutral. The liquid was separated, and the aqueous phase was extracted with 500 ml of toluene, washed with water, dried over anhydrous sodium sulfate, and filled with silica gel and passed through a column. The column liquid was concentrated to about 200 ml, and 300 ml of ethanol was added for crystallization for 1 h. The mixture was filtered and dried. The resulting solid was recrystallized from toluene and dried to obtain 77.2 g of off-white solid S1;

[0040] S2: 150 mmol of S1, 160 mmol of p-chlorophenylboronic acid, 300 mmol of potassium carbonate, 1.5 mmol of palladium acetate were added to a reaction flask, and 450 ml of toluene, 65 ml of ethanol, and 190 ml of water were added. The atmosphere was replaced with nitrogen and refluxed for 2 h. After the reaction of the raw materials was completed, the reaction was stopped, 200 ml of water was added each time, the mixture was washed with water three times, dried over anhydrous sodium sulfate, filled with silica gel and passed through a column, concentrated to 130 ml, and crystallized with 130 ml of ethanol for 0.5 h. The mixture was filtered and dried. The resulting solid was recrystallized from toluene and dried to obtain 57.9 g of off-white solid S2;

[0041] S3: Add 100 mmol of S2, 120 mmol of diboronic acid pinacol ester, 200 mmol of potassium acetate, 0.5 mmol of Pd2(dba)3, 1 mmol of X-phos, and 450 mL of 1,4-dioxane to the reaction flask. Replace the atmosphere with nitrogen and reflux for 4 h. Once the reaction is complete, stop the reaction. Concentrate to almost dryness, add 900 mL of dichloromethane, dissolve in 0.5 L of water, separate the liquids, wash the organic phase with water until neutral, dry with anhydrous sodium sulfate, fill with silica gel and pass through a column, concentrate until a large amount of solid precipitates, add 200 mL of petroleum ether and crystallize for 0.5 h, filter, and dry to obtain 43.6 g of off-white solid compound 1.

[0042] S4: Prepare a Grignard solution with 400 mmol of 4-bromopyridine, 405 mmol of magnesium chips, and 320 mL of tetrahydrofuran, and store it in an ice bath at 5°C. Add 200 mmol of cyanuric chloride and 300 ml of tetrahydrofuran to the reaction flask, cool it to 5°C, and slowly add the prepared Grignard solution dropwise to the reaction system at around 30°C. After the addition is complete, raise the temperature to 30°C and react for 2 hours. Stop the reaction, slowly pour the reaction solution into dilute hydrochloric acid to quench it, extract it with tetrahydrofuran, wash it with saturated brine, extract it with tetrahydrofuran, wash it with saturated brine, concentrate it to dryness, add 1.5 L of toluene to dissolve it and pass it through a column, concentrate it to 150 ml to crystallize it for 1 hour, filter and dry it, and recrystallize the obtained solid from toluene to obtain 24.3 g of off-white solid S4;

[0043] S5: Add 70 mmol of S4, 80 mmol of compound 1, 140 mmol of potassium carbonate, 0.35 mmol of palladium acetate to the reaction flask, add 140 ml of toluene, 20 ml of ethanol, 60 ml of water, replace with nitrogen, reflux for 16 hours, a small amount of S4 remains, stop the reaction, cool the reactant to room temperature, add water, filter, and wash with water. The obtained solid is slurried with 100 ml of ethanol, filtered and dried, heated and dissolved in 1 L of toluene, filled with silica gel and passed through a column, the column liquid is concentrated to 80 ml, crystallized for 1 hour, filtered and dried to obtain 12.8 g of off-white solid ET10.

[0044] ET10 was tested by LCMS, and the data obtained were as follows:

[0045] ESI-MS: C45H28N6, standard molecular weight 652.74, test result 653.25 [M+H].

[0046] Example 3:

[0047] Preparation of ET16:

[0048] S1: 300 mmol of 2,7-dibromophenanthrene, 450 mmol of carbazole, 600 mmol of sodium tert-butoxide, 1.5 mmol of Pd2(dba)3, and 3 mmol of X-phos were added to a reaction flask, and the atmosphere was replaced with nitrogen. The reaction was refluxed for 2 h. The carbazole portion remained, and the reaction was stopped. 500 ml of water was added and neutralized with dilute acid until neutral. The liquid was separated, and the aqueous phase was extracted with 500 ml of toluene, washed with water, dried over anhydrous sodium sulfate, and filled with silica gel and passed through a column. The column liquid was concentrated to about 200 ml, and 300 ml of ethanol was added for crystallization for 1 h. The mixture was filtered and dried. The resulting solid was recrystallized from toluene and dried to obtain 77.2 g of off-white solid S1;

[0049] S2: 150 mmol of S1, 160 mmol of p-chlorophenylboronic acid, 300 mmol of potassium carbonate, 1.5 mmol of palladium acetate were added to a reaction flask, and 450 ml of toluene, 65 ml of ethanol, and 190 ml of water were added. The atmosphere was replaced with nitrogen and refluxed for 2 h. After the reaction of the raw materials was completed, the reaction was stopped, 200 ml of water was added each time, the mixture was washed with water three times, dried over anhydrous sodium sulfate, filled with silica gel and passed through a column, concentrated to 130 ml, and crystallized with 130 ml of ethanol for 0.5 h. The mixture was filtered and dried. The resulting solid was recrystallized from toluene and dried to obtain 57.9 g of off-white solid S2;

[0050] S3: Add 100 mmol of S2, 120 mmol of diboronic acid pinacol ester, 200 mmol of potassium acetate, 0.5 mmol of Pd2(dba)3, 1 mmol of X-phos, and 450 mL of 1,4-dioxane to the reaction flask. Replace the atmosphere with nitrogen and reflux for 4 h. Once the reaction is complete, stop the reaction. Concentrate to almost dryness, add 900 mL of dichloromethane, dissolve in 0.5 L of water, separate the liquids, wash the organic phase with water until neutral, dry with anhydrous sodium sulfate, fill with silica gel and pass through a column, concentrate until a large amount of solid precipitates, add 200 mL of petroleum ether and crystallize for 0.5 h, filter, and dry to obtain 43.6 g of off-white solid compound 1.

[0051] S4: 400mmol of bromobenzene, 405mmol of magnesium chips, and 640mL of tetrahydrofuran were used to prepare phenylmagnesium bromide, which was then stored in an ice bath at 5°C. 400mmol of cyanuric chloride (CAS: 108-77-0) and 300ml of tetrahydrofuran were added to the reaction flask, and the temperature was lowered to 5°C. The prepared deuterated phenylmagnesium bromide solution was slowly added dropwise to the reaction system at a temperature of about 30°C. After the addition was complete, the temperature was raised to 30°C and the reaction was allowed to proceed for 2h. The reaction was stopped and the reaction solution was slowly poured into dilute hydrochloric acid to quench the solution. The solution was extracted with tetrahydrofuran, washed with saturated brine, and concentrated to dryness. 1.5L of toluene was added to dissolve the solution and passed through a column. The solution was concentrated to 150ml for crystallization for 1h, filtered and dried, and the obtained solid was recrystallized from toluene to obtain 63.2g of off-white solid S4.

[0052] S5: Prepare a Grignard solution with 200 mmol of 4-(4-bromophenyl)pyridine, 205 mmol of magnesium chips, and 450 mL of tetrahydrofuran, and store it in an ice bath at 5°C. Add 280 mmol of S4 and 160 ml of tetrahydrofuran to the reaction flask, cool it to 5°C, and slowly add the prepared Grignard solution dropwise to the reaction system at a temperature of about 30°C. After the addition is complete, raise the temperature to 30°C and react for 2 hours. Stop the reaction, slowly pour the reaction solution into dilute hydrochloric acid to quench it, extract it with tetrahydrofuran, wash it with saturated brine, concentrate it to dryness, add 3.2 L of toluene to dissolve it and pass it through a column, concentrate it to 160 ml and crystallize it for 1 hour, filter and dry it, and the obtained solid toluene is recrystallized to obtain 34.7 g of off-white solid S5;

[0053] S6: Add 70 mmol of S5, 80 mmol of compound 1, 140 mmol of potassium carbonate, 0.35 mmol of palladium acetate to the reaction flask, add 140 ml of toluene, 20 ml of ethanol, 60 ml of water, replace with nitrogen, reflux for 16 hours, a small amount of S5 remains, stop the reaction, cool the reactant to room temperature, add water, filter, and wash with water. The obtained solid is slurried with 100 ml of ethanol, filtered and dried, heated and dissolved in 1 L of toluene, filled with silica gel and passed through a column, the column liquid is concentrated to 80 ml, crystallized for 1 hour, filtered and dried to obtain 14.8 g of off-white solid ET16.

[0054] ET16 was tested by LCMS, and the data obtained were as follows:

[0055] ESI-MS: C52H33N5, standard molecular weight 727.85, test result 728.30 [M+H].

[0056] Results and Testing

[0057] The blue OLED device was connected to a power supply (brand: Keithley; model: 2400) and tested using a PR650 luminance meter. The OLED device was tested at a brightness of 1000 nits.

[0058]

[0059] Implementation Case 2 has lower driving voltage, higher current efficiency, and higher external quantum efficiency by introducing pyridine groups, triazine groups, and carbazole groups. Due to its symmetrical structure and higher stability, it has a longer service life.

[0060] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A triazine-based fused-ring electron transport material containing an aromatic group, characterized in that: The structural formula is: 、 、 。 2. A triazine-based fused-ring electron transport material containing an aromatic group according to claim 1, characterized in that: The intermediate for synthesizing triazine-based electron transport materials containing aromatic fused rings is compound 1; The structural formula of the compound 1 is: .

3. A triazine-based aromatic fused ring electron transport material according to claim 2, characterized in that: The preparation method of compound 1 is: S1: 2,7-dibromophenanthrene, potassium carbonate, a metal catalyst, a metal catalyst ligand, and toluene are purged with nitrogen to replace the air and then refluxed to obtain S1. S2: placing the S1 in a reactor, adding p-chlorophenylboric acid, potassium carbonate, palladium acetate, toluene, ethanol and deionized water, introducing nitrogen to replace the air and then performing a reflux reaction. After the reaction is completed, purification is performed to obtain S2; S3: The S2 is placed in a reactor, and diboronic acid pinacol ester, potassium acetate, a metal catalyst, a metal catalyst ligand and 1,4-dioxane are added. Nitrogen is introduced to replace the air and then reflux reaction is carried out. After the reaction is completed, purification is carried out to obtain the compound 1.

4. A triazine-based fused-ring electron transport material containing an aromatic group according to claim 3, characterized in that: The metal catalyst is Pd2(dba)3.

5. The triazine-based aromatic fused ring electron transport material according to claim 3, characterized in that: The metal catalyst ligand is X-phos.

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