Preparation method and application of ionic organic-inorganic hybrid blue luminescent material

Abstract

The present invention relates to a preparation method and application of an ionic organic-inorganic hybrid blue luminescent material, comprising the following steps: adding a halogenated precursor ionic liquid, a cadmium halide metal salt and Ag[TCDPPA] to acetonitrile, and obtaining the ionic organic-inorganic hybrid blue luminescent material by stirring, filtering, evaporating and filtering. The present invention adopts a double decomposition reaction, and compared with traditional blue luminescent materials, the present invention has the advantages of simple synthesis, mild reaction, pure chromaticity, high luminescence efficiency, etc.

Description

Technical Field

[0001] The invention belongs to blue luminescent materials, and in particular relates to a preparation method of an ionic organic-inorganic hybrid blue luminescent material.

[0002] The invention also relates to the application of the above method. Background Art

[0003] According to the range of luminescent wavelength, luminescent materials can be divided into red, green and blue materials, which are the core of organic light-emitting semiconductors (OLEDs). Red, blue and green primary color luminescent materials with excellent thermal stability, high color purity and balanced efficiency are widely used in full-color display, white light lighting and other fields. Among organic electroluminescent materials, blue light materials are particularly important. They can not only provide the blue light required for lighting and display, effectively reducing energy consumption, but also realize the emission of red and green light through energy transfer. At present, the research on red and green light materials and devices has been relatively mature, with good performance, which can basically meet the needs of industrialization, while the development of blue luminescent materials is relatively lagging and is still in its infancy. This is because the blue light material itself has high energy, large inherent energy gap and relatively short luminescent wavelength, which makes it difficult to inject charge into the luminescent material. In addition, the problems of poor stability and unbalanced charge transfer lead to poor light output and luminous efficiency of blue light electroluminescent devices, and the color purity and stability still need to be improved. Therefore, in order to further improve the performance of organic electroluminescent devices and improve color display technology, it is necessary to develop blue luminescent materials with better performance.

[0004] According to the different materials, blue luminescent materials can be divided into inorganic, organic and organic-inorganic hybrid materials. Organic-inorganic hybrid luminescent materials combine the advantages of inorganic and organic materials and show good development prospects. Compared with neutral blue luminescent materials, ionic organic-inorganic hybrid materials are very stable, soluble in organic solvents and easy to process. Ionic organic-inorganic hybrid materials can be assembled from organic cations and metal-containing anions or metal-containing cations and organic / inorganic anions or metal-containing cations and anions. The rich changes and diverse combinations of organic and inorganic components make them more adjustable.

[0005] High-efficiency and low-cost alternative luminescent materials have been highly anticipated. 10 Transition metals with d-d transition configurations may be a good choice because they are environmentally friendly and do not have the luminescence quenching problem caused by dd transitions. 10 Organic-inorganic hybrid materials of transition metals are very promising blue luminescent materials. β-diketone ligands have high light absorption coefficients, strong chelating and coordination capabilities for metal central ions, and can fine-tune the skeleton and substituents as needed, making them very promising ligands.

[0006] Based on the above research background, the present invention uses a β-diketone-like ligand, 2,2,2-trichloro-N-(di(pyrrolidin-1-yl)phosphoryl)acetamide, abbreviated as: HTCDPPA) as a ligand, which coordinates with Cd(II) ions to form coordinated anions, and assembles with organic cations to prepare ionic organic-inorganic hybrid blue luminescent materials. There is no literature report on this research. Summary of the invention

[0007] The purpose of the present invention is to provide an ionic organic-inorganic hybrid blue luminescent material and a preparation method and application thereof.

[0008] The invention provides a method for preparing an ionic organic-inorganic hybrid blue luminescent material, which uses a β-diketone-like ligand TCDPPA as a ligand, uses its silver salt as a raw material, and carries out a double decomposition reaction with different halogenated precursor ionic liquids and cadmium halide salts to prepare the ionic organic-inorganic hybrid material, which can be used as a new blue luminescent material.

[0009] The chemical composition of the ionic organic-inorganic hybrid blue luminescent material is: [C4mpy][Cd(TCDPPA)3]; wherein (C4mpy) + is 1-butyl-4-methylpyridinium ion; TCDPPA is 2,2,2-trichloro-N-(di(pyrrolidin-1-yl)phosphoryl)acetamide.

[0010] The ionic organic-inorganic hybrid blue luminescent material is composed of an organic cation (C4mpy) + and [Cd(TCDPPA)3] - The coordinated anion composition has a zero-dimensional crystal structure. - In the coordinated anion, the cadmium (II) ion is supported by three (TCDPPA) - These organic cations and coordinated anions interact with each other through a large number of weak interactions. a -axes are stacked alternately to assemble into a three-dimensional supramolecular crystal structure.

[0011] Fluorescence performance tests show that the maximum excitation wavelength of [C4mpy][Cd(TCDPPA)3] is at about 369 nm, and the maximum emission wavelength is at 435 nm (Figure 1). Its CIE coordinates are 0.1746, 0.1655, which is located in the deep blue light region ( Figure 2 ). Its fluorescence decay curve is a double exponential fit with an average lifetime of 3.32 ns (τ1: 0.80 ns, 31.50 %; τ2: 4.48 ns, 68.50 %).

[0012] The present invention adopts double decomposition reaction, and compared with traditional blue luminescent materials, the present invention has the advantages of simple synthesis, mild reaction, pure chromaticity, high luminescent efficiency, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Solid-state excitation and emission spectra of [C4mpy][Cd(TCDPPA)3] of the present invention.

[0014] Figure 2 CIE diagram of [C4mpy][Cd(TCDPPA)3] of the present invention. DETAILED DESCRIPTION

[0015] The ionic organic-inorganic blue luminescent material [C4mpy][Cd(TCDPPA)3] obtained by the present invention has single crystal unit cell parameters: monoclinic system, space group P twenty one / c ; a = 10.4176(5) Å; b = 25.6545(14) Å; c = 43.528(2) Å; α = 90 o ; β = 93.403(2) o ; γ = 90 o ; V = 11612.8(10) Å 3 ; Z = 8.

[0016] The main steps of preparing the blue luminescent material are as follows: using a halogenated precursor ionic liquid, a cadmium halide metal salt and Ag[TCDPPA] as raw materials, adopting a double decomposition reaction, stirring, filtering, evaporating and filtering, to obtain an ionic organic-inorganic hybrid blue luminescent material. The halogenated precursor ionic liquid and the cadmium halide metal salt involved in this step can be chloride, bromide or iodide, and can be combined in any way, which is not used to limit the scope of the present invention.

[0017] [C4mpy][Cd(TCDPPA)3] is composed of organic cation (C4mpy) + and [Cd(TCDPPA)3] - The coordinated anion composition has a zero-dimensional crystal structure. - In the coordinated anion, the cadmium (II) ion is supported by three (TCDPPA) - These organic cations and coordinated anions interact with each other through a large number of weak interactions.a -axes are stacked alternately to assemble into a three-dimensional supramolecular crystal structure.

[0018] The specific implementation manner of the present invention is further described below in conjunction with specific embodiments.

[0019] Example 1

[0020] Ag(TCDPPA) (0.4555 g, 1 mmol), precursor ionic liquid (C4mpy)Cl (1 / 3 mmol, 0.0619 g), CdCl2·2H2O (0.076 g, 1 / 3 mmol) and 20 mL of acetonitrile were placed in a vial (25 mL) wrapped in aluminum foil and stirred for 3 hours. Filter, place the filtrate in a vial, cover the bottle mouth with a sealing film, let it stand, and slowly evaporate at room temperature. Colorless block crystals are produced after about a week. The crystals are collected by filtration and washed with 95% ethanol. The yield is 72%.

[0021] Example 2

[0022] Ag(TCDPPA) (0.4555 g, 1 mmol), precursor ionic liquid (C4mpy)Br (1 / 3 mmol, 0.0768 g), CdCl2·2H2O (0.076 g, 1 / 3 mmol) and 20 mL of acetonitrile were placed in a vial (25 mL) wrapped in aluminum foil and stirred for 3 hours. Filter, place the filtrate in a vial, cover the bottle mouth with a sealing film, let it stand, and slowly evaporate at room temperature. Colorless block crystals are produced after about a week. The crystals are collected by filtration and washed with 95% ethanol. The yield is 78%.

[0023] Example 3

[0024] Ag(TCDPPA) (0.4555 g, 1 mmol), precursor ionic liquid (C4mpy)I (1 / 3 mmol, 0.0924 g), CdCl2·2H2O (0.076 g, 1 / 3 mmol) and 20 mL of acetonitrile were placed in a vial (25 mL) wrapped in aluminum foil and stirred for 3 hours. Filter, place the filtrate in a vial, cover the bottle mouth with a sealing film, let it stand, and slowly evaporate at room temperature. Colorless block crystals are produced after about a week. The crystals are collected by filtration and washed with 95% ethanol. The yield is 70%.

[0025] Example 4

[0026] Ag(TCDPPA) (0.4555 g, 1 mmol), precursor ionic liquid (C4mpy)Cl (1 / 3 mmol, 0.0768 g), CdBr2·4H2O (0.1148 g, 1 / 3 mmol) and 20 mL of acetonitrile were placed in a vial (25 mL) wrapped in aluminum foil and stirred for 3 hours. Filter, place the filtrate in a vial, cover the bottle mouth with a sealing film, let it stand, and slowly evaporate at room temperature. Colorless block crystals are produced after about a week. The crystals are collected by filtration and washed with 95% ethanol. The yield is 68%.

[0027] Example 5

[0028] Ag(TCDPPA) (0.4555 g, 1 mmol), precursor ionic liquid (C4mpy)Br (1 / 3 mmol, 0.0768 g), CdBr2·4H2O (0.1148 g, 1 / 3 mmol) and 20 mL of acetonitrile were placed in a vial (25 mL) wrapped in aluminum foil and stirred for 3 hours. Filter, place the filtrate in a vial, cover the bottle mouth with a sealing film, let it stand, and slowly evaporate at room temperature. Colorless block crystals are produced after about a week. The crystals are collected by filtration and washed with 95% ethanol. The yield is 66%.

[0029] Example 6

[0030] Ag(TCDPPA) (0.4555 g, 1 mmol), precursor ionic liquid (C4mpy)I (1 / 3 mmol, 0.0768 g), CdBr2·4H2O (0.1148 g, 1 / 3 mmol) and 20 mL of acetonitrile were placed in a vial (25 mL) wrapped in aluminum foil and stirred for 3 hours. Filter, place the filtrate in a vial, cover the bottle mouth with a sealing film, let it stand, and slowly evaporate at room temperature. Colorless block crystals are produced after about a week. The crystals are collected by filtration and washed with 95% ethanol. The yield is 65%.

[0031] Example 7

[0032] Ag(TCDPPA) (0.4555 g, 1 mmol), precursor ionic liquid (C4mpy)Cl (1 / 3 mmol, 0.0619 g), CdCl2·2H2O (0.076 g, 1 / 3 mmol) and 20 mL of ethanol were placed in a vial (25 mL) wrapped in aluminum foil and stirred for 3 hours. Filter, place the filtrate in a vial, cover the bottle mouth with a sealing film, let it stand, and slowly evaporate at room temperature. Colorless block crystals are produced after about a week. The crystals are collected by filtration and washed with 95% ethanol. The yield is 61%.

[0033] Example 8

[0034] Ag(TCDPPA) (0.4555 g, 1 mmol), precursor ionic liquid (C4mpy)Br (1 / 3 mmol, 0.0768 g), CdCl2·2H2O (0.076 g, 1 / 3 mmol) and 20 mL of ethanol were placed in a vial (25 mL) wrapped in aluminum foil and stirred for 3 hours. Filter, place the filtrate in a vial, cover the bottle mouth with a sealing film, let it stand, and slowly evaporate at room temperature. Colorless block crystals are produced after about a week. The crystals are collected by filtration and washed with 95% ethanol. The yield is 58%.

[0035] Example 9

[0036] Ag(TCDPPA) (0.4555 g, 1 mmol), precursor ionic liquid (C4mpy)I (1 / 3 mmol, 0.0924 g), CdCl2·2H2O (0.076 g, 1 / 3 mmol) and 20 mL of ethanol were placed in a vial (25 mL) wrapped in aluminum foil and stirred for 3 hours. Filter, place the filtrate in a vial, cover the bottle mouth with a sealing film, let it stand, and slowly evaporate at room temperature. Colorless block crystals are produced after about a week. The crystals are collected by filtration and washed with 95% ethanol. The yield is 64%.

Claims

1. An ionic organic-inorganic hybrid blue luminescent material, characterized in that Its chemical formula is: [C4mpy][Cd(TCDPPA)3], where (C4mpy) + 1-butyl-4-methylpyridinium ion; [TCDPPA] - = 2,2,2-trichloro-N-(di(pyrrolidin-1-yl)phosphoryl)acetamide; the single crystal unit cell parameters of the material are: monoclinic system, space group P twenty one / c ; a =10.4176(5) Å; b = 25.6545(14) Å; c = 43.528(2) Å; α = 90°; β = 93.403(2)°; γ =90°; V = 11612.8(10) Å 3 ; Z = 8; The material is composed of anions and cations, the cation is 1-butyl-4-methylpyridinium ion, and the anion is [Cd(TCDPPA)3] having a zero-dimensional structure - Coordinating anions.

2. The method for synthesizing a blue luminescent material according to claim 1, characterized in that The following steps are involved: The halogenated precursor ionic liquid, cadmium halide metal salt and Ag[TCDPPA] are used as raw materials, double decomposition reaction is adopted, and the ionic organic-inorganic hybrid blue luminescent material is obtained through stirring, filtering, evaporation and filtering.

3. The method for synthesizing a blue luminescent material according to claim 2, characterized in that: Acetonitrile or ethanol is used as solvent, and the molar ratio of the precursor ionic liquid, the metal salt and Ag[TCDPPA] is 1:1:

3.

4. The method for synthesizing a blue luminescent material according to claim 2, wherein: The halogenated precursor ionic liquids are [C4mpy]Cl, [C4mpy]Br and [C4mpy]I.

5. The method for synthesizing a blue luminescent material according to claim 2, characterized in that: The cadmium halide metal salt is cadmium chloride, cadmium bromide or cadmium iodide.

6. The blue luminescent material according to claim 1, characterized in that: The maximum absorption wavelength is 369 nm, the maximum emission wavelength is 435 nm, and the CIE (1931) coordinates are 0.1746, 0.1655.

7. The ionic blue luminescent material according to claim 1, characterized in that: When the excitation wavelength is 369 nm and the monitoring wavelength is 435 nm, the average fluorescence lifetime is 3.32 ns.

8. The ionic blue luminescent material according to claim 1, characterized in that: When the excitation wavelength is 369nm, the absolute quantum yield is 20.32%.

9. The use of the blue luminescent material according to claim 1, characterized in that: Used in OLED, lighting and display devices.

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