Synthesis method of one-dimensional lanthanide molecular cluster fluorescent material

Abstract

The invention is applicable to the technical field of chemical materials, and provides a synthesis method of a one-dimensional lanthanide molecular cluster fluorescent material, the method uses two high-absorption antenna ligands pentafluorobenzoic acid and 1, 10-phenanthroline to realize dual modulation, and due to the similarity of trivalent lanthanide elements in chemical reaction, the one-dimensional lanthanide molecular cluster fluorescent material can be used for preparing a high-absorption antenna. Homogeneous metal materials and heterogeneous metal materials with different light-emitting wavebands can be customized according to the light-emitting characteristics of all the elements, the fluorescence quantum yield of the homogeneous metal [[Nd (phen) (pfbz) 3] n] reaches 1.12%, and the heterogeneous metal materials can achieve full-waveband output from visible light to near-infrared light through doping. The method provides an efficient and stable synthesis process of the one-dimensional lanthanide molecular cluster fluorescent material, is simple to operate and low in energy consumption, and does not need harsh synthesis environments such as high temperature and high pressure; and the prepared lanthanide cluster material has a crystal structure, high-efficiency luminescence capability, strong repeatability and good stability.

Description

Technical Field

[0001] This invention belongs to the field of chemical materials technology, and particularly relates to a method for synthesizing one-dimensional lanthanide molecular cluster fluorescent materials. Background Technology

[0002] In recent years, lanthanide-based nanomaterials have occupied an important position among various luminescent materials developed by humans. Lanthanide clusters have a greater advantage in the field of photoluminescence due to their narrow emission lines, long excited-state lifetimes, tunable wavelengths, wide coverage, and multiple energy levels.

[0003] However, compounds based on trivalent lanthanides are still constrained by two fundamental physical limitations: firstly, the forbidden ff transition in trivalent lanthanide ions leads to their low absorbance coefficients; secondly, the primary nonradiative decay pathway involves multiphonon relaxation and vibrational energy transfer. Although rare-earth-doped nanomaterials have made recent progress in luminescent materials, research in the field of one-dimensional pure rare-earth clusters remains limited, and achieving efficient luminescence remains a formidable challenge. Summary of the Invention

[0004] The purpose of this invention is to provide a method for synthesizing one-dimensional lanthanide molecular cluster fluorescent materials, aiming to solve the problems mentioned in the background art.

[0005] The present invention is implemented as follows: a method for synthesizing one-dimensional lanthanide molecular cluster fluorescent materials includes the following steps: Step 1: Prepare a mixed solution of methanol and acetonitrile in a fume hood and place it in a quartz glass bottle for later use; Step 2: Calculate the proportion of each lanthanide element. If the target sample is a homogeneous metal material, only the corresponding Ln(Ac)3·xH2O is used. If the target sample is a heterogeneous metal material, under the premise that the total molar amount of lanthanum acetate hydrate raw material remains unchanged, the amount of each element is determined according to the proportion of each lanthanide ion in the total lanthanide ions in the target sample. Step 3: Add the following to the mixed solvent prepared in Step 1 in sequence: 0.05 mmol Ln(Ac)3·xH2O, 0.5 mmol pentafluorobenzoic acid, and 0.15 mmol 1,10-phenanthroline, and stir until the solid is completely dissolved; Step 4: Place the mixed solution obtained in Step 3 into an ultrasonic reactor and react for 30 minutes; Step 5: Use a nylon microporous filter head to perform initial filtration of the solution to remove insoluble impurities; Step 6: Transfer the filtrate to a constant temperature oven, raise the temperature to 80°C using a gradient heating method, and maintain the temperature for 24 hours; Step 7: After removing the solution, filter it again using a nylon filter head to remove impurities precipitated at high temperature; Step 8: Place the filtrate in a vibration-free, well-ventilated environment and let it stand for 3-5 days until blocky crystals precipitate at the bottom of the quartz bottle, thus obtaining a one-dimensional lanthanide molecular cluster fluorescent material. Step 9: Purify the crude product; Step 9.1: Add the prepared methanol and acetonitrile mixed solvent to the mixture containing crystals; Step 9.2: Shake the bottle on a vibrating mixer to allow the crystals on the bottle wall to settle and dissolve any remaining impurities. Step 9.3: Use a dropper to remove the supernatant and repeat the washing process 3 times to remove surface-adsorbed impurities; Step 9.4: Air dry at room temperature to obtain the high-purity target material, which is a one-dimensional lanthanide molecular cluster fluorescent material.

[0006] In a further technical solution, in step 1, the volume ratio of the methanol and acetonitrile mixed solution is 2:3. If the amount of raw materials added is 0.05, 0.5 and 0.15 mmol, then the total volume of the mixed solution is 5 ml.

[0007] In a further technical solution, in step 4, the vibration frequency of the ultrasonic instrument should be controlled at 40 kHz.

[0008] In a further technical solution, in step 5, the nylon filter head has a diameter of 13 mm and a pore size of 0.45 μm.

[0009] In a further technical solution, the bulk crystal obtained in step 8 has the chemical formula [[Ln(phen)(pfbz)3] n ].

[0010] In a further technical solution, in step 9, the number of repetitions of the single crystal cleaning process needs to be controlled to within 3 times.

[0011] This invention provides a method for synthesizing one-dimensional lanthanide molecular cluster fluorescent materials. This method utilizes pentafluorobenzoic acid and 1,10-phenanthroline, two high-absorption antenna ligands, to achieve dual modulation. Due to the similarity of trivalent lanthanide elements in chemical reactions, homometallic and heterometallic materials with different emission bands can be customized based on the luminescence characteristics of each element. The homometallic material [[Nd(phen)(pfbz)3]] n The fluorescence quantum yield reached 1.12%, and heterometallic materials could achieve full-band output from visible to near-infrared light through doping. This method provides an efficient and stable synthesis process for one-dimensional lanthanide molecular cluster fluorescent materials. It is simple to operate, low in energy consumption, and does not require harsh synthesis environments such as high temperature and high pressure. The prepared lanthanide cluster materials have a crystal structure, high efficiency in luminescence, strong reproducibility, and good stability. Attached Figure Description

[0012] Figure 1 [[Ln(phen)(pfbz)3]] n A structural diagram of [ ]; Figure 2 [[Ln(phen)(pfbz)3]] n Comparison between measured XRD patterns and XRD patterns obtained from single-crystal structure analysis; Figure 3 [[Ln(phen)(pfbz)3]] n ]{Nd n The emission spectrum of}; Figure 4 [[Ln(phen)(pfbz)3]] n ]{Nd n The excitation spectrum of}; Figure 5 [[Ln(phen)(pfbz)3]] n ]{Nd n The temperature-dependent emission spectrum of}; Figure 6 [[Ln(phen)(pfbz)3]] n ]{Nd n The temperature-dependent excitation spectrum of}. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0014] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0015] Example 1: Preparation of [[Ln(phen)(pfbz)3] n ]{Nd n}; Step 1: Prepare a 5 ml mixture of methanol and acetonitrile in a 2:3 volume ratio in a fume hood and store it in a quartz glass bottle for later use. Step 2: Take 0.05 mmol of Nd(Ac)3·xH2O (0.016 g), 0.5 mmol of pentafluorobenzoic acid (pfbz) (0.106 g), and 0.15 mmol of 1,10-phenanthroline (phen) (0.027 g) and add them together to the prepared methanol and acetonitrile mixed solution, and wait for the solid to completely dissolve; Step 3: Place the obtained mixed solution in an ultrasonic reactor and react for 30 minutes at a vibration frequency of 40 kHz; Step 4: Use a nylon microporous filter head to perform initial filtration of the solution to remove insoluble impurities. The nylon filter head used has a diameter of 13 mm and a pore size of 0.45 μm. Step 5: Transfer the filtrate to a constant temperature oven, raise the temperature to 80°C using a gradient heating method, and maintain the temperature for 24 hours; Step 6: After removing the solution, filter it again using a nylon filter head to remove impurities precipitated at high temperature; Step 7: Place the filtrate in a vibration-free, well-ventilated environment and let it stand for 3-5 days until blocky crystals precipitate at the bottom of the quartz bottle, thus obtaining a one-dimensional lanthanide molecular cluster fluorescent material, namely [[Ln(phen)(pfbz)3]]. n ]{Nd n}; Step 8: Purify the crude product; Step 8.1: Add the prepared methanol and acetonitrile mixed solvent to the mixture containing crystals; Step 8.2: Shake the bottle on a vibrating mixer to allow the crystals on the bottle wall to settle and dissolve any remaining impurities. Step 8.3: Use a dropper to remove the supernatant and repeat the washing process 3 times to remove surface-adsorbed impurities; Step 8.4: Air dry at room temperature to obtain the high-purity target material, which is a one-dimensional lanthanide molecular cluster fluorescent material.

[0016] In this embodiment of the invention, for the calculation of the proportion of each lanthanide element, if the target sample is a homogeneous metal material, only the corresponding Ln(Ac)3·xH2O is taken; if the target sample is a heterogeneous metal material, under the premise that the total molar amount of lanthanum acetate hydrate raw material remains unchanged, the amount of each element used is determined according to the proportion of each lanthanide ion in the total lanthanide ions in the target sample.

[0017] like Figure 1 As shown, the nanoscale cluster material containing multiple lanthanide metal luminescent centers synthesized using this method has a symmetrical structure and a short inter-center spacing. Figure 2 As shown, this method synthesizes [[Ln(phen)(pfbz)3] n The measured XRD pattern and the peak positions of the XRD pattern obtained from single-crystal structure analysis are close, indicating that there are few byproducts, enabling large-scale synthesis with considerable yield and no need for purification. Figure 3 As shown, this method synthesizes [[Ln(phen)(pfbz)3] n The significant near-infrared emission indicates that this system can effectively sensitize Nd. 3+ .like Figure 4 As shown, this method synthesizes [[Ln(phen)(pfbz)3] n The excitation spectrum of [ ] also indicates that this system can open Nd [ ] 3+ The jump restriction enables efficient energy transfer. For example... Figure 5 As shown, [[Ln(phen)(pfbz)3] n The emission intensity changes very little at different temperatures, indicating that it is minimally affected by temperature and possesses good stability. Figure 6 As shown, [[Ln(phen)(pfbz)3] n The excitation intensity remained almost unchanged at different temperatures, indicating that the energy transfer rate is minimally affected by temperature. n Good stability also provides a prerequisite for its application.

[0018] This method utilizes lanthanum acetate hydrate [Ln(Ac)3·xH2O] to prepare one-dimensional lanthanide molecular cluster materials with efficient and stable luminescence properties. This material system uses pentafluorobenzoic acid (pfbz) and 1,10-phenanthroline (phen) as high-absorption ligand antennas. The components can be flexibly customized according to requirements to achieve luminescence in different wavelengths. Multiple metal luminescent centers that are close to each other can generate rich interactions and have good stability.

[0019] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for synthesizing one-dimensional lanthanide molecular cluster fluorescent materials, characterized in that, Includes the following steps: Step 1: Prepare a mixed solution of methanol and acetonitrile in a fume hood and place it in a quartz glass bottle for later use; Step 2: Calculate the proportion of each lanthanide element. If the target sample is a homogeneous metal material, only the corresponding Ln(Ac)3·xH2O is used. If the target sample is a heterogeneous metal material, under the premise that the total molar amount of lanthanum acetate hydrate raw material remains unchanged, the amount of each element is determined according to the proportion of each lanthanide ion in the total lanthanide ions in the target sample. Step 3: Add the following to the mixed solvent prepared in Step 1 in sequence: 0.05 mmol Ln(Ac)3·xH2O, 0.5 mmol pentafluorobenzoic acid, and 0.15 mmol 1,10-phenanthroline, and stir until the solid is completely dissolved; Step 4: Place the mixed solution obtained in Step 3 into an ultrasonic reactor and react for 30 minutes; Step 5: Use a nylon microporous filter head to perform initial filtration of the solution to remove insoluble impurities; Step 6: Transfer the filtrate to a constant temperature oven, raise the temperature to 80°C using a gradient heating method, and maintain the temperature for 24 hours; Step 7: After removing the solution, filter it again using a nylon filter head to remove impurities precipitated at high temperature; Step 8: Place the filtrate in a vibration-free, well-ventilated environment and let it stand for 3-5 days until blocky crystals precipitate at the bottom of the quartz bottle, thus obtaining a one-dimensional lanthanide molecular cluster fluorescent material. Step 9: Purify the crude product.

2. The method for synthesizing one-dimensional lanthanide molecular cluster fluorescent materials according to claim 1, characterized in that, In step 1, the volume ratio of the methanol and acetonitrile mixture is 2:

3. If the amount of raw materials added is 0.05, 0.5 and 0.15 mmol, the total volume of the mixture is 5 ml.

3. The method for synthesizing one-dimensional lanthanide molecular cluster fluorescent materials according to claim 1, characterized in that, In step 4, the vibration frequency of the ultrasonic instrument should be controlled at 40 kHz.

4. The method for synthesizing one-dimensional lanthanide molecular cluster fluorescent materials according to claim 1, characterized in that, In step 5, the nylon filter head has a diameter of 13 mm and a pore size of 0.45 μm.

5. The method for synthesizing one-dimensional lanthanide molecular cluster fluorescent materials according to claim 1, characterized in that, In step 8, the chemical formula of the obtained bulk crystal is [[Ln(phen)(pfbz)3] n ].

6. The method for synthesizing one-dimensional lanthanide molecular cluster fluorescent materials according to claim 1, characterized in that, Step 9 includes the following specific steps: Step 9.1: Add the prepared methanol and acetonitrile mixed solvent to the mixture containing crystals; Step 9.2: Shake the bottle on a vibrating mixer to allow the crystals on the bottle wall to settle and dissolve any remaining impurities. Step 9.3: Use a dropper to remove the supernatant and repeat the washing process 3 times to remove surface-adsorbed impurities; Step 9.4: Air dry at room temperature to obtain the high-purity target material, which is a one-dimensional lanthanide molecular cluster fluorescent material.

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