Monocarborane anion-containing metal iridium complex luminescent material, and preparation method and application thereof
By introducing a monocarborane anionic ligand into the metal iridium complex, an efficient metal iridium complex luminescent material containing monocarborane anion was designed, which solved the problem of low luminescence efficiency of traditional iridium complexes in the solid state, and achieved high solid state luminescent efficiency and good stability.
Patent Information
- Application Number
- CN202411560585.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-04
- Publication Date
- 2025-03-07
AI Technical Summary
The luminescence intensity of traditional metal iridium phosphorescent complexes has significantly weakened in solid-state aggregation state, showing solid-state aggregation luminescence quenching, and its luminescence efficiency is low, making it difficult to meet the market's demand for high-quality OLEDs.
By introducing a monocarborane anionic ligand, a luminescent material containing a monocarborane anionic metal iridium complex is designed. This material has high luminescence efficiency in a solid state, and has adjustable emission wavelength and good stability.
The phosphorescent materials with high solid-state luminescence efficiency, adjustable emission wavelength and good stability are achieved, solving the problems of low luminescence efficiency and insufficient stability of traditional iridium complex materials.
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Figure CN119569786A_ABST
Abstract
Description
[Technical field]
[0001] The invention belongs to the technical field of organic photoelectric materials, and specifically relates to a luminescent material containing a metal iridium complex containing a monocarborane anion, a preparation method and an application thereof. [Background technology]
[0002] In recent years, OLED technology has developed rapidly, and various materials used in OLED devices have also been tapped out like mushrooms after rain. Organic light-emitting diodes (OLEDs) have great potential in the application of optoelectronic devices (such as flat panel displays and lighting). In order to improve the luminous efficiency of organic light-emitting diodes, various fluorescent and phosphorescent luminescent material systems have been developed because of their advantages such as high resolution, flexible and bendable display, low power consumption, and wide viewing angle.
[0003] Among various metal complex luminescent materials, iridium (III) complexes have the characteristics of phosphorescent emission at room temperature, relatively short phosphorescent lifetime, high quantum yield, good stability, etc., and the luminescent color can be adjusted in the visible light region and even in the near-infrared region, including changing the conjugated structure of the ligand, introducing electron-donating or electron-withdrawing substituent groups in the ligand, etc. Therefore, such complexes are widely used in organic electroluminescent devices (OLEDs).
[0004] However, traditional metal iridium phosphorescent complexes usually have high luminescence efficiency in solution, but the luminescence intensity will be significantly weakened in the aggregated state, showing solid-state aggregation luminescence quenching. In addition, as a key luminescent material in OLED devices, it is also necessary to comprehensively consider factors such as its stability, efficiency and cost to meet the market's growing demand for high-quality OLEDs. Therefore, solving solid-state aggregation fluorescence quenching and improving luminescence efficiency have become the key to developing iridium complex phosphorescent materials. [Summary of the invention]
[0005] In order to solve the above problems, the present invention provides a monocarborane-functionalized neutral trivalent metal iridium complex luminescent material, which has the advantages of high solid-state luminescence efficiency, adjustable emission wavelength, good stability, etc., and solves the problems of scarcity and low luminescence efficiency of existing solid-state phosphorescence enhanced iridium complex materials.
[0006] The present invention is achieved through the following technical scheme, and provides a luminescent material containing a monocarborane anion metal iridium complex, which has the following general structural formula:
[0007]
[0008] The combination of R1 and R2 includes the following two cases: R1 and R2 are both H or R1=CF3, R2=F; Select any one of the following structural formulas:
[0009]
[0010] It is a monocarborane.
[0011] The present invention also provides a method for preparing a metal iridium complex containing a monocarborane anion, comprising the following steps:
[0012] S1: adding hydrated iridium trichloride and compound I to solvent one at a ratio of 1:2, stirring and reacting at 120°C for 7 hours, and separating to obtain dichloro bridge compound II, the structural formula of which is as follows:
[0013]
[0014] S2 Compound IV is prepared as follows: carborane is placed in a reaction bottle, the air in the bottle is evacuated with a vacuum pump, and N2 is introduced, anhydrous tetrahydrofuran is added under an N2 atmosphere, and the reaction solution is stirred at -78°C to -30°C, n-butyl lithium is added to the reaction solution, and the reaction is stirred for 1.5 hours, and then cuprous iodide is added, and stirring is continued for 1 hour, and then compound III, Pd(OAc)2, and tri(2-methoxyphenyl)phosphine are added, and the reaction is stirred at room temperature for 15 to 30 hours. The compound III, carborane (Et4NCB 11 H 12 ), n-butyl lithium (n-BuLi), and cuprous iodide (CuI) in a molar ratio of 1:1:1:1; the molar ratio of the compound III, the palladium catalyst, and the phosphorus ligand is (2.5-3.5):(0.05-0.1):(2.5-3);
[0015]
[0016] S3 After the reaction of S2 is completed, the solid is filtered with diatomaceous earth to obtain a reaction solution, and anhydrous tetrahydrofuran is removed in vacuo. The obtained solid is dissolved with methyl tert-butyl ether and diethyl ether, and the organic phase is extracted three times with hydrochloric acid. The organic phase is taken and rotary evaporated to obtain a solid, which is dissolved in water, and the pH is adjusted with a base until the aqueous solution is alkaline, and the pH after adjustment is 8.5-10.5. A solid product is obtained by cation exchange, and compound IV can be obtained by separation and purification by column chromatography;
[0017] S4: adding dichloro bridge compound II and compound IV in a ratio of 1:2 to ethylene glycol solvent, reacting at 150° C. for 8 h to obtain a reaction mixture, wherein the mass volume ratio of compound II to ethylene glycol is 0.4-0.6 g / ml;
[0018] S5: After the reaction mixture is cooled to room temperature, water is added after the reaction is completed, wherein the volume ratio of water to ethylene glycol is (3-6):1, and the mixture is centrifuged three times, and the upper solution is sucked off with a dropper to obtain a precipitate, and excess water is removed by suction filtration, and then purified by column chromatography to obtain a neutral trivalent metal iridium complex VI, i.e., a metal iridium complex containing a monocarborane anion, whose structural formula is as follows:
[0019]
[0020] Particularly, the solvent 1 in S1 is water and 2-methoxyethanol in a ratio of 1:2 to 1:4, and the mass volume ratio of the compound I to the solvent 1 is 0.3 to 0.5 g / ml; the structural formula of the compound I is as follows:
[0021]
[0022] In particular, the compound IV in S3 is any one of the following structural formulas:
[0023]
[0024] In particular, when the structural formula of the compound IV is 4 or 5, bromopentane and acetonitrile solvents are also added, and the compound V is obtained after reacting at 100° C. for 8 hours. The molar ratio of the compound IV to bromopentane is 1:(2.5-4.5), and the mass volume ratio of bromopentane to acetonitrile is 0.4-0.6 g / ml.
[0025] In particular, the structural formulas corresponding to the compound V are as follows:
[0026]
[0027] The present invention also provides an application of a metal iridium complex containing a monocarborane anion. The metal iridium complex containing a monocarborane anion is applied to an organic electroluminescent device.
[0028] The present invention provides a method for preparing a luminescent material containing a monocarborane anion metal iridium complex with a simple synthesis method. By introducing a monocarborane anion ligand with a special electronic effect and a three-dimensional structure, the interaction between luminescent molecules is effectively reduced, thereby inhibiting the generation of excimers, and obtaining a type of phosphorescent material with high solid-state luminescence efficiency, adjustable emission wavelength, and good stability that can be applied to the field of electroluminescence, thereby solving the problems of scarcity and low luminescence efficiency of existing solid-state phosphorescence-enhanced iridium complex materials.
Brief Description of the Drawings
[0029] Figure 1 The UV absorption spectra of the solutions of Examples 1a, 1b and 1c of the present invention;
[0030] Figure 2 are absorption and emission diagrams of solutions of Examples 1a, 1b and 1c of the present invention;
[0031] Figure 3 : are the emission spectra of the solutions of Examples 1a, 1b and 1c of the present invention;
[0032] Figure 4 is the solid emission spectrum of Examples 1a, 1b and 1c of the present invention;
[0033] Figure 5 : PMMA emission spectra of Examples 1a, 1b and 1c of the present invention;
[0034] Figure 6 is a crystal structure diagram of Example 1b of the present invention;
[0035] Figure 7 This is a crystal structure diagram of Example 1c of the present invention. [Specific implementation method]
[0036] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.
[0037] The present invention provides a luminescent material containing a monocarborane anion metal iridium complex and a preparation method thereof. The iridium complex can effectively realize blue-green light emission and belongs to the technical field of electroluminescence. The metal complex prepared by the preparation method has the following general structural formula:
[0038]
[0039] Wherein R1 and R2 are electron-withdrawing groups CF3 or F, and the bidentate chelating ligand XY is carborane pyridine imidazole, carborane pyridine phenyl imidazole or carborane bipyridine. The preparation method introduces a caged carborane anion with a 3D structure into a pyridine imidazole or bipyridine auxiliary ligand, and then coordinates with metal iridium through a phenylpyridine main ligand, thereby obtaining a blue-green phosphorescent luminescent material with a novel structure and high-efficiency luminescent performance. The introduction of monocarborane not only realizes the overall electrical neutrality of the complex molecule, but also effectively improves the stability and photoluminescent performance of the iridium phosphorescent material through its special electronic effect and the steric hindrance of the bulky structure.
[0040] The specific preparation method of the monocarborane anion-containing metal iridium complex luminescent material is as follows:
[0041] S1: adding hydrated iridium trichloride and compound I to solvent one in a ratio of 1:2, stirring and reacting at 120°C for 7 hours, and separating and obtaining dichloro bridge compound II; the structural formula of the dichloro bridge compound II is as follows:
[0042]
[0043] The solvent 1 is water and 2-methoxyethanol in a ratio of 1:2, and its structural formula is as follows:
[0044]
[0045] There are two cases for the combination of R1 and R2: R1 and R2 are both H or R1=CF3, R2=F.
[0046] S2: Put carborane into a reaction bottle, evacuate the air in the bottle with a vacuum pump, and introduce N2, add anhydrous tetrahydrofuran under N2 atmosphere, and stir at -78°C to -30°C, add n-butyl lithium to the reaction solution, and stir for 1.5 hours, then add cuprous iodide, stir for 45 minutes, mix compound III, palladium catalyst, and phosphorus ligand, and continue to stir for 20 to 24 hours at room temperature; the compound III is any one of the following structural formulas:
[0047]
[0048] S3 After the reaction of S2 is completed, the solid is filtered with diatomaceous earth to obtain a reaction solution, and anhydrous tetrahydrofuran is removed in vacuo. The obtained solid is dissolved with methyl tert-butyl ether and diethyl ether, and the organic phase is extracted three times with hydrochloric acid. The organic phase is taken and rotary evaporated to obtain a solid, which is dissolved in water, and the pH is adjusted with a base until the aqueous solution is alkaline. A solid product is obtained by cation exchange, and compound IV can be obtained by separation and purification by column chromatography; the compound IV is any one of the following structural formulas:
[0049]
[0050] In the present invention, if the structural formula of compound IV is 4 or 5, bromopentane and acetonitrile solvents are further added, the molar ratio of compound IV to bromopentane is 1:(2.5-4.5), the mass volume ratio of bromopentane to acetonitrile is 0.4-0.6 g / ml, and the reaction is carried out at 100° C. for 8 hours to obtain compound V; the structural formulas corresponding to compound V are as follows:
[0051]
[0052] S4: adding dichloro bridge compound II, compound IV (structural formula shown in C) or compound V into ethylene glycol solvent at a ratio of 1:2, and reacting at 150° C. for 8 hours to obtain a reaction mixture.
[0053] S5 After the reaction mixture is cooled to room temperature, an appropriate amount of aqueous solution is added after the reaction is completed, and the mixture is centrifuged three times. The upper solution is sucked off with a dropper to obtain a precipitate, and excess water is removed by suction filtration. The precipitate is then purified by column chromatography to obtain a neutral trivalent metal iridium complex VI, i.e., a metal iridium complex containing a monocarborane anion, and the structural formula thereof is as follows:
[0054]
[0055] The combination of R1 and R2 includes the following two cases: R1 and R2 are both H or R1=CF3, R2=F; Select any one of the following structural formulas:
[0056]
[0057] It is a monocarborane.
[0058] The above-mentioned preparation method is simple, has mild reaction conditions and good practicability. In order to make the present invention more clear, the present invention is further explained below in conjunction with specific examples.
[0059] Example 1
[0060] This embodiment provides a metal iridium complex 1a containing a monocarborane anion, and its structural formula is as follows:
[0061]
[0062] The synthetic route of the metal iridium complex 1a containing monocarborane anion is as follows:
[0063]
[0064] The specific preparation steps are as follows:
[0065] (i) Add iridium trichloride hydrate (100 mg, 0.3 mmol) and 2-phenylpyridine (98.10 mg, 0.6 mmol) to a reaction microwave test tube, add 2 ml of 2-methoxyethanol and 1 ml of water, set the microwave device, the reaction temperature is 120° C., and the reaction time is 7 h. After the reaction is completed, the precipitate is separated by suction filtration to obtain dichloro bridge compound a.
[0066] (ii) Carborane (300 mg, 1.1 mmol) was placed in a nitrogen environment, dissolved in 15 ml of anhydrous tetrahydrofuran, stirred, and n-butyl lithium was added. After a period of reaction, cuprous iodide (163 mg, 0.9 mmol) was added. After a period of reaction, palladium acetate (20 mg, 0.1 mmol), tris (2-methoxyphenyl) phosphine (91 mg, 0.3 mmol), and compound I-3 (200 mg, 0.9 mmol) were added and reacted under a nitrogen environment. After the reaction was completed, the solid was filtered, the obtained filtrate was vacuum dried, the solid was dissolved with ether, extracted with hydrochloric acid, the organic phase was dried, and cation exchange was performed to obtain a solid crude product, which was separated and purified by column chromatography to obtain compound g.
[0067] (iii) The obtained dichloro bridge compound a (100 mg, 0.1 mmol) and compound g (80 mg, 0.3 mmol) were added to a reaction microwave test tube, 4 ml of ethylene glycol was added, and the microwave device was set to a reaction temperature of 150° C. and a reaction time of 8 h. After the reaction mixture was cooled to room temperature, an appropriate amount of aqueous solution was added after the reaction was completed, and the mixture was centrifuged three times. The upper solution was aspirated with a dropper to obtain a precipitate, and excess water was removed by suction filtration. Then, the obtained neutral trivalent metal iridium complex 1a was purified by column chromatography.
[0068] Example 2
[0069] This embodiment provides a metal iridium complex 1c containing a monocarborane anion, and its structural formula is as follows:
[0070]
[0071] The synthetic route of the metal iridium complex 1c containing monocarborane anion is as follows:
[0072]
[0073] The specific preparation steps are as follows:
[0074] (i) Add hydrated iridium trichloride (100 mg, 0.3 mmol) and 2-phenylpyridine (98.10 mg, 0.6 mmol) to a reaction microwave test tube, add 2 ml of 2-methoxyethanol and 1 ml of water, set the microwave device, the reaction temperature is 120° C., and the reaction time is 7 h. After the reaction is completed, the precipitate is separated by suction filtration to obtain dichloro bridge compound a.
[0075] (ii) Carborane (300 mg, 1.1 mmol) was placed in a nitrogen environment, dissolved in 15 ml of anhydrous tetrahydrofuran, stirred, and n-butyl lithium was added. After a period of reaction, cuprous iodide (318 mg, 1.7 mmol) was added. After a period of reaction, palladium acetate (45 mg, 0.2 mmol), tris (2-methoxyphenyl) phosphine (175 mg, 0.5 mmol), and compound I-1 (373 mg, 1.7 mmol) were added and reacted under a nitrogen environment. After the reaction was completed, the solid was filtered, the obtained filtrate was vacuum dried, the solid was dissolved with ether, extracted with hydrochloric acid, the organic phase was dried, and cation exchange was performed to obtain a solid crude product, which was separated and purified by column chromatography to obtain compound b.
[0076] (iii) Compound b (90 mg, 3.1 mmol) and 0.3 ml of bromopentane were added to a reaction microwave test tube, and 2 ml of acetonitrile was added. The microwave device was set to a reaction temperature of 100° C. and a reaction time of 8 h. After the reaction was completed, the reaction solution was transferred to a round-bottom flask and the acetonitrile was removed to obtain a dark green oily solid. The dark green oily solid was then repeatedly washed three times with an appropriate amount of n-hexane and dried to obtain compound c.
[0077] (iv) The obtained dichloro bridge compound a (100 mg, 0.1 mmol) and compound c (80 mg, 0.2 mmol) were added to a reaction microwave test tube, 4 ml of ethylene glycol was added, and the microwave device was set to a reaction temperature of 150° C. and a reaction time of 8 h. After the reaction mixture was cooled to room temperature, an appropriate amount of aqueous solution was added after the reaction was completed, and the mixture was centrifuged three times. The upper solution was aspirated with a dropper to obtain a precipitate, and excess water was removed by suction filtration. Then, the neutral trivalent metal iridium complex 1c was purified by column chromatography.
[0078] Example 3
[0079] This embodiment provides a metal iridium complex 1b containing a monocarborane anion, the structural formula of which is as follows:
[0080]
[0081] The synthetic route of the metal iridium complex 1b containing monocarborane anion is as follows:
[0082]
[0083] The specific preparation steps of the metal iridium complex 1b containing monocarborane anion refer to Example 2, except that 2-phenylpyridine is replaced by 2-(2,4-difluorophenyl)-5-(trifluoromethyl)pyridine.
[0084] The ultraviolet absorption spectrum, absorption emission, etc. of the above-mentioned embodiment are further explained and illustrated by specific experiments below.
[0085] At room temperature, compounds 1a, 1b, and 1c were dissolved in chromatographic grade dichloromethane and their UV absorption spectra were tested. Figure 1 As shown by Figure 1 It can be seen that compounds 1a and 1c show strong absorption bands in the high energy region near 230nm~270nm and medium absorption bands near 230nm, and their molar extinction coefficients are 7.9×10 4 M -1 cm -1 , 5.5×10 4 M -1 cm -1 Compound 1b also shows strong absorption bands in this region, and the molar extinction coefficients are 8.2×10 4 M -1 cm -1 It is inferred that the high-energy absorption bands of the compound located at 230nm and 260mm are spin-allowed ligand-ligand ( 1 LL) and the ligand internal ( 1 In addition, the three compounds all showed a low energy absorption band near 380nm, and the molar extinction coefficients were all lower than 1.0×10 4 M -1 cm -1 Due to weak absorption and the mixing of singlet and triplet states caused by atomic spin coupling, it is difficult to distinguish 1 MLCT and 3 MLCT. Compound 1a exhibits strong orange-yellow phosphorescence emission in both solid and liquid solutions, such as Figure 3 and Figure 4 As shown, the emission maximum of deoxygenated dichloromethane is at 580 nm. Compounds 1b and 1c exhibit strong blue-green phosphorescence emission in both solid and liquid solutions, such as Figure 3 , Figure 4 As shown, the emission maximum of deoxygenated dichloromethane is in the range of 460 to 520 nm. Figure 5 The emission spectra of compounds 1a, 1b, and 1c in 2% PMMA film are very similar to those in deoxygenated dichloromethane.
[0086] It can be seen that the preparation method of the novel carborane anion functionalized iridium complex luminescent material provided by the present invention is simple, the reaction conditions are mild, and the synthesized material has high chemical stability and luminescence efficiency, and is suitable for application in the luminescent layer material in organic electroluminescent devices, and can effectively improve the stability and luminescence efficiency of the device.
Claims
1. A luminescent material containing a monocarborane anion metal iridium complex, characterized in that: It has the following general structural formula: The combination of R1 and R2 includes the following two cases: R1 and R2 are both H or R1=CF3, R2=F; Select any one of the following structural formulas: It is a monocarborane.
2. A method for preparing a metal iridium complex containing a monocarborane anion according to claim 1, characterized in that: The following steps are involved: S1: adding hydrated iridium trichloride and compound I to solvent one at a ratio of 1:2, stirring and reacting at 120°C for 7 hours, and separating to obtain dichloro bridge compound II, the structural formula of which is as follows: S2 Compound IV is prepared as follows: carborane is placed in a reaction bottle, the air in the bottle is evacuated with a vacuum pump, and N2 is introduced, anhydrous tetrahydrofuran is added under an N2 atmosphere, and the reaction solution is stirred at -78°C to -30°C, n-butyl lithium is added to the reaction solution, and the reaction is stirred for 1.5 hours, and then cuprous iodide is added, and stirring is continued for 1 hour, and then compound III, Pd(OAc)2, and tri(2-methoxyphenyl)phosphine are added, and the reaction is stirred at room temperature for 15 to 30 hours, and the molar ratio of the compound III, carborane, n-butyl lithium, and cuprous iodide is 1:1:1:1; the molar ratio of the compound III, palladium catalyst, and phosphorus ligand is (2.5 to 3.5):(0.05 to 0.1):(2.5 to 3); the structure of the compound III is as follows: S3 After the reaction of S2 is completed, the solid is filtered with diatomaceous earth to obtain a reaction solution, and anhydrous tetrahydrofuran is removed in vacuo. The obtained solid is dissolved with methyl tert-butyl ether and diethyl ether, and the organic phase is extracted three times with hydrochloric acid. The organic phase is taken and rotary evaporated to obtain a solid, which is dissolved in water, and the pH is adjusted with a base until the aqueous solution is alkaline, and the pH after adjustment is 8.5-10.
5. A solid product is obtained by cation exchange, and compound IV can be obtained by separation and purification by column chromatography; S4: adding dichloro bridge compound II and compound IV in a ratio of 1:2 to ethylene glycol solvent, reacting at 150° C. for 8 h to obtain a reaction mixture, wherein the mass volume ratio of compound II to ethylene glycol is 0.4-0.6 g / ml; S5: After the reaction mixture is cooled to room temperature, water is added after the reaction is completed, wherein the volume ratio of water to ethylene glycol is (3-6):1, and the mixture is centrifuged three times, and the upper solution is sucked off with a dropper to obtain a precipitate, and excess water is removed by suction filtration, and then purified by column chromatography to obtain a neutral trivalent metal iridium complex VI, i.e., a metal iridium complex containing a monocarborane anion, whose structural formula is as follows:
3. The method for preparing a metal iridium complex containing a monocarborane anion according to claim 2, characterized in that: The solvent 1 in S1 is water and 2-methoxyethanol in a ratio of 1:2 to 1:4, and the mass volume ratio of the compound I to the solvent 1 is 0.3 to 0.5 g / ml; the structural formula of the compound I is as follows:
4. The method for preparing a metal iridium complex containing a monocarborane anion according to claim 2, characterized in that: The compound IV in S3 is any one of the following structural formulas:
5. The method for preparing a metal iridium complex containing a monocarborane anion according to claim 4, characterized in that: When the structural formula of the compound IV is 4 or 5, bromopentane and acetonitrile solvents are further added, and the reaction is carried out at 100° C. for 8 hours to obtain compound V. The molar ratio of the compound IV to bromopentane is 1:(2.5-4.5), and the mass volume ratio of bromopentane to acetonitrile is 0.4-0.6 g / ml.
6. The method for preparing a metal iridium complex containing a monocarborane anion according to claim 5, characterized in that: The structural formulas corresponding to the compound V are as follows:
7. An application of a metal iridium complex containing a monocarborane anion, characterized in that: The monocarborane anion-containing metal iridium complex is applied to an organic electroluminescent device.