Silver cluster material as well as preparation method and application thereof
By preparing the silver cluster material C62H52AgCl4P4SbF6 and utilizing the CH…F hydrogen bond interaction to restrict molecular motion, the problem that existing metal cluster materials cannot simultaneously possess aggregation-induced emission and crystallization-induced emission was solved, thus achieving a highly efficient emission enhancement effect.
Patent Information
- Application Number
- CN202511192014.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-25
- Publication Date
- 2025-12-16
AI Technical Summary
Existing metal cluster materials cannot simultaneously possess both aggregation-induced emission and crystallization-induced emission properties, requiring multi-dimensional fine-tuning of their internal and external structures.
The silver cluster material C62H52AgCl4P4SbF6 is used. The internal and external CH…F hydrogen bond interactions restrict the movement of molecules. The preparation method includes the reaction of silver hexafluoroantimonate, phosphine ligand and sodium borohydride. Using sterically hindered phosphine ligand and polyfluorinated anion SbF6-, a highly efficient silver cluster is formed under light-protected and room temperature conditions.
Highly efficient luminescence of silver cluster materials in both crystalline and aggregated states was achieved, with a luminescence quantum yield of up to 40.75% and an emission peak at 478 nm. The materials exhibit significant enhancements in aggregation-induced luminescence and crystallization-induced luminescence.
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Figure CN121135767A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the interdisciplinary field of nanomaterials and coordination chemistry, and in particular relates to a silver cluster material, its preparation method, and its application in aggregation-induced emission and crystallization-induced emission. Background Technology
[0002] Traditional luminescent materials, in solution or amorphous states, exhibit relatively active intramolecular motion, leading to frequent dissipation of excited-state energy through non-radiative pathways and reduced luminescence intensity. The discovery of aggregation-induced emission (AIE) and crystallization-induced emission (CIE) effects provides a pathway to address the problems of aggregation-induced quenching (ACQ) and low quantum yield in traditional luminescent materials. In crystalline or aggregated states, intramolecular motion is effectively confined, resulting in significantly enhanced luminescence efficiency and adhering to a restricted intramolecular motion (RIM) mechanism. With the continuous reporting of molecules possessing AIE or CIE properties and the ongoing expansion of their applications, these materials have demonstrated enormous commercial potential in fields such as bioimaging, sensing, optoelectronic devices, and information displays. Currently, metal clusters, due to their unique size effect, tunable crystal structure, and controllable aggregation behavior, have become ideal material carriers integrating both AIE and CIE properties. Metal clusters possessing both AIE and CIE properties achieve highly efficient luminescence through a dual mechanism of ordered lattice confinement of molecular motion and aggregation-state suppression of non-radiative transitions.
[0003] Currently, although metal clusters with single AIE or CIE properties have been extensively explored, metal clusters with both AIE and CIE properties are still rarely reported. This requires multi-dimensional fine-tuning of the non-covalent interactions existing in their internal / external structures. Summary of the Invention
[0004] To address the aforementioned problems in the background art, the present invention aims to provide a silver cluster material with strong CH…F hydrogen bond interactions both internally and externally. By restricting intramolecular / intermolecular motion, nonradiative transition pathways are effectively suppressed, thereby exhibiting enhanced aggregation-induced emission and enhanced crystallization-induced emission characteristics.
[0005] To achieve the above objectives, the present invention employs the following technical solution: a silver cluster compound material, wherein the chemical formula of the silver cluster compound material is C0. 62 H 52 AgCl4P4SbF6, abbreviated as Ag(BDPB)2SbF6·2CH2Cl2, is a silver cluster material belonging to the monoclinic crystal system; its space group is [missing information].
[0006] P21 / c, α=90°, β=90.782(2)°, γ=90°, The molecular weight is 1406.33 Da, and BDPB is 1,2-bis(diphenylphosphine)benzene, with the following structural formula:
[0007]
[0008] Further description of the structure of silver cluster compound materials:
[0009] Preferably, the silver cluster material contains one Ag atom, two BDPB organic ligands, and one counterion SbF6. — And 2 CH2Cl2 solvent molecules.
[0010] The second objective of this invention is to provide a method for preparing the silver cluster compound material described in any one of the above claims, comprising the following steps:
[0011] S1. Dissolve silver hexafluoroantimonate and phosphine ligands in a mixed solvent of dichloromethane and methanol, and stir until homogeneous;
[0012] S2. Add sodium borohydride aqueous solution to the obtained mixture and react in the dark at room temperature. The solution first changes from colorless to brown, and finally turns back into a colorless solution. Add distilled water to the colorless solution to remove water-soluble impurities, then add excess n-hexane for washing and centrifugation to obtain crude product.
[0013] S3. Dissolve the crude product in dichloromethane, introduce diethyl ether into the solution for gas-phase diffusion to induce crystal formation, collect the crystals and dry them to obtain the silver cluster material.
[0014] As a further improvement to the preparation method of silver cluster materials:
[0015] Preferably, the molar ratio of silver hexafluoroantimonate, phosphine ligand and sodium borohydride is 1:(1-1.6):(4.4-7.2).
[0016] Preferably, in step S1, dichloromethane and methanol are mixed in a volume ratio of (6-9):1 to form a mixed solvent.
[0017] Preferably, the concentration of silver hexafluoroantimonate in the mixed solvent in step S1 is 0.005-0.085 mmol / mL.
[0018] Preferably, the phosphine ligand in step S1 is 1,2-bis(diphenylphosphine)benzene; and the reaction in step S2 is carried out in the dark at room temperature for 8-14 hours.
[0019] A third objective of this invention is to provide the application of the silver cluster compound material described in any one of the above-mentioned methods in aggregation-induced emission and crystallization-induced emission.
[0020] Further improvements to the application of silver cluster materials in aggregation-induced emission and crystallization-induced emission:
[0021] Preferably, the application process of aggregation-induced emission is as follows: equal amounts of silver cluster material are dissolved in pure DMF and a 90% water-volume H2O / DMF mixed solvent, respectively, with a dissolution concentration of 250 μg / mL, and are denoted as solution 1 and solution 2, respectively; the emission peak intensities of solution 1 and solution 2 are compared using a light emission spectrometer, and the size distribution of the silver cluster material in solution 2 is measured using a laser particle size analyzer to verify the aggregation-induced emission performance of the silver cluster material.
[0022] Preferably, the application process of crystallization-induced luminescence is as follows: the silver cluster material is dissolved in pure DMF to form a silver cluster material solution with a concentration of 250 μg / mL, denoted as solution 1; the luminescence quantum yield and emission peak intensity of the silver cluster material are tested and compared with the emission peak intensity of solution 1 to verify the crystallization-induced luminescence performance of the silver cluster material.
[0023] The advantages of this invention compared to the prior art are as follows:
[0024] (1) This invention provides a silver cluster compound material with both aggregation-induced emission and crystallization-induced emission properties, with the chemical formula C. 62 H 52 AgCl4P4SbF6. This silver cluster material exhibits no fluorescence in solution, but strong emission characteristics in both crystalline and aggregated states. The crystalline emission peak is located at 478 nm, with a luminescence lifetime of 7.25 μs and a high luminescence quantum yield of 40.75%.
[0025] (2) This invention provides a one-pot method for high-yield synthesis of silver cluster materials. In this synthesis system, the sterically hindered phosphine ligand 1,2-bis(diphenylphosphine)benzene acts as a key stabilizer and structure-directing agent, effectively controlling the spatial structure and size of the final silver cluster material. The counterion SbF6 in the silver salt... - By forming strong non-covalent interactions (C–H…F hydrogen bonds) with hydrogen atoms in neighboring phosphine ligands and solvent molecules, the relative motion within and between molecules is significantly restricted, and non-radiative transition processes are suppressed. This results in the prepared silver cluster materials exhibiting both significant aggregation-induced emission enhancement (AIE) and crystallization-induced emission enhancement (CIE) properties. The reaction is carried out under light-protected, room-temperature conditions. Kinetic control is achieved by adding sodium borohydride as a reducing agent, directionally forming silver clusters with a specific number of nuclei. The use of a mixed solvent ensures the homogeneity of the reaction system. The product is initially purified by precipitation with a poor solvent (n-hexane), and then high-quality single crystals are grown by gas-phase diffusion, suitable for structural analysis and performance testing. The key to this synthetic method lies in the selection of the sterically hindered phosphine ligand 1,2-bis(diphenylphosphine)benzene and the polyfluorinated anion SbF6.- Using silver salts as reactants, this method enables the efficient preparation of small-nucleus silver cluster materials with atomically precise structures. The synthesis process is simple, mild, and low-cost: it requires no calcination or complex processes and can be achieved at room temperature and pressure. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the structure of the silver cluster materials prepared in Examples 1-3 of the present invention.
[0027] Figure 2 The 5 mg silver cluster material prepared in Example 1 was dispersed at equal concentrations in water with different volume fractions (f w Images of H2O / DMF mixed solvents (0-90%) under 365nm UV light irradiation, showing the water volume fraction gradually increasing from left to right.
[0028] Figure 3 The silver cluster material prepared in Example 1 was dispersed in water with a volume fraction f w Excitation and emission spectra in a 90% H2O / DMF mixed solvent.
[0029] Figure 4 The emission spectrum of the silver cluster material prepared in Example 1, dispersed at equal concentrations in a mixed solvent of H2O / DMF with water volume fractions of 0% and 90%, is shown with an excitation wavelength of 350 nm.
[0030] Figure 5 The particle size distribution of the silver cluster material prepared in Example 1 dispersed in a H2O / DMF mixed solvent with a water volume fraction of 90% is shown.
[0031] Figure 6 Images of the silver cluster material crystal prepared in Example 1 under natural light (left) and 365nm ultraviolet light (right).
[0032] Figure 7 The image shows the excitation spectrum of the silver cluster material prepared in Example 1.
[0033] Figure 8 The emission spectra of the silver cluster material prepared in Example 1 in both solution and crystalline states are shown, with an excitation wavelength of 370 nm.
[0034] Figure 9 The luminescence decay curve and lifetime fitting curve of the silver cluster material prepared in Example 1 are shown.
[0035] Figure 10 The image shows the luminescence quantum yield test result of the silver cluster compound material prepared in Example 1.
[0036] Figure 11This is a schematic diagram of the CH…F hydrogen bond interactions in the unit cell structure of the silver cluster material prepared in Example 1. The interaction distance is represented by dashed lines, and the numbers represent bond lengths (units). ). Detailed Implementation
[0037] 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 embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0038] Example 1
[0039] This embodiment provides a method for preparing a silver cluster compound material, specifically including the following steps:
[0040] S1. Dissolve silver hexafluoroantimonate (20 mg, 0.058 mmol) and 1,2-bis(diphenylphosphine)benzene (27 mg, 0.0605 mmol) in a mixed solvent of 6 mL dichloromethane and 1 mL methanol, and stir until the mixture is homogeneous.
[0041] S2. Add 1 mL of sodium borohydride aqueous solution (10 mg / mL, 1 mL contains 0.265 mmol of sodium borohydride) to the obtained mixture, and react at room temperature in the dark for 14 hours. The solution first changes from colorless to brown, and finally turns back to colorless. Add distilled water to the colorless solution to remove water-soluble impurities, then add excess n-hexane for washing and centrifugation to obtain the crude product. The molar ratio of silver hexafluoroantimonate, phosphine ligand in step S1 and sodium borohydride aqueous solution in step S2 is 1:1.04:4.57.
[0042] S3. Dissolve the crude product in dichloromethane, and introduce diethyl ether into the solution to induce gas-phase diffusion and crystal formation; collect the crystals and dry them to obtain the silver cluster material 1.
[0043] Example 2
[0044] S1. Dissolve silver hexafluoroantimonate (20 mg, 0.058 mmol) and 1,2-bis(diphenylphosphine)benzene (40 mg, 0.0896 mmol) in a mixed solvent of 9 mL dichloromethane and 1 mL methanol, and stir until the mixture is homogeneous.
[0045] S2. Add 1.5 mL of sodium borohydride aqueous solution (10 mg / mL, 1 mL contains 0.265 mmol of sodium borohydride) to the obtained mixture, and react at room temperature in the dark for 8 hours. The solution first changes from colorless to brown, and finally turns back to colorless. Add distilled water to the colorless solution to remove water-soluble impurities, then add excess n-hexane for washing and centrifugation to obtain the crude product. The molar ratio of silver hexafluoroantimonate, phosphine ligand in step S1 and sodium borohydride aqueous solution in step S2 is 1,2-bis(diphenylphosphine)benzene 1:1.54:6.85.
[0046] S3. Dissolve the crude product in dichloromethane, and introduce diethyl ether into the solution to induce gas-phase diffusion and crystal formation; collect the crystals and dry them to obtain the silver cluster material 2.
[0047] Example 3
[0048] S1. Dissolve silver hexafluoroantimonate (20 mg, 0.058 mmol) and 1,2-bis(diphenylphosphine)benzene (35 mg, 0.0784 mmol) in a mixed solvent of 8 mL dichloromethane and 1 mL methanol, and stir until the mixture is homogeneous.
[0049] S2. Add 1.25 mL of sodium borohydride aqueous solution (10 mg / mL, 1 mL contains 0.265 mmol of sodium borohydride) to the obtained mixture, and react at room temperature in the dark for 12 hours. The solution first changes from colorless to brown, and finally turns back to colorless. Add distilled water to the colorless solution to remove water-soluble impurities, then add excess n-hexane for washing and centrifugation to obtain the crude product. The molar ratio of silver hexafluoroantimonate, phosphine ligand in step S1 and sodium borohydride aqueous solution in step S2 is 1:1.35:5.71.
[0050] S3. Dissolve the crude product in dichloromethane, and introduce diethyl ether into the solution to induce gas-phase diffusion and crystal formation; collect the crystals and dry them to obtain the silver cluster material 3.
[0051] The silver cluster materials of the present invention prepared in Examples 1-3 were further characterized as follows:
[0052] (1) Crystal structure determination
[0053] The crystalline silver cluster materials 1-3 obtained in Examples 1-3 were tested under a microscope using a single-crystal X-ray diffractometer (Bruker D8 Venture) under nitrogen protection and a low temperature of 193 K. Monochromatization with a graphite monochromator was also performed. Mo-Kα diffraction was performed, and the diffraction data were collected using the ω-scan method. The single-crystal structure was obtained by direct method using the SHELXL-97 software program, and the refinement method used was the least squares F-method.2 Empirical absorption correction was performed using the SADABS procedure. First, the positions of all non-hydrogen atoms were determined and anisotropic corrections were applied. All Ag, P, Sb, F, Cl, and C atoms were directly identified. The refinement of hydrogen atom positions in the molecule was obtained using isotropic calculations. Detailed crystallographic data are shown in Table 1. Figure 1 As shown, the results indicate that the molecular formula of the analyzed silver cluster compound material is C2. 62 H 52 AgCl4P4SbF6, abbreviated as Ag(BDPB)2SbF6·2CH2Cl2, has a precise structure consisting of one Ag atom, two BDPB organic ligands, and one counterion SbF6. — It consists of two CH2Cl2 solvent molecules.
[0054] Table 1. Main crystallographic parameters
[0055]
[0056]
[0057] (2) Application of the silver cluster material of the present invention in aggregation-induced emission and crystallization-induced emission
[0058] 1.1 The aggregation-induced emission application includes the following process: 5 mg of silver cluster material is dispersed in equal amounts in 20 mL of pure N,N-dimethylformamide (DMF) and 20 mL of H2O / DMF mixed solvent with a water volume fraction of 0-90%, and both are prepared into solutions of equal concentration of 250 μg / mL, which are denoted as solution 1 and solution 2, respectively; the emission peak intensities of solution 1 and solution 2 are compared using a light emission spectrometer, and the size distribution of silver cluster material in solution 2 is determined using a laser particle size analyzer.
[0059] 1.2 The application of crystallization-induced emission includes the following process: collect silver cluster material, dissolve the silver cluster material in pure DMF to form a silver cluster material solution with a concentration of 250 μg / mL, denoted as solution 1; test the luminescence quantum yield and emission peak intensity of the silver cluster material, and compare it with the emission peak intensity of solution 1.
[0060] Take multiple 5mg portions of the silver cluster compound material 1 prepared in Example 1, and disperse them sequentially in 20mL solutions containing different water volume fractions (f w Images of a mixed H2O / DMF solvent (0-90%) under 365nm UV light irradiation were obtained. The results are as follows: Figure 2 As shown in the figure. It can be seen that from left to right, the water volume fraction gradually increases (f w =0~50%), the solution does not exhibit luminescence, when the water volume fraction f wWhen the concentration is increased to 60-90%, the solution exhibits strong luminescence.
[0061] Figure 3 The silver cluster material 1 prepared in Example 1 was dispersed in 20 mL of water with a volume fraction f w Excitation and emission spectra of a 90% H₂O / DMF mixed solvent (instrument model: PerkinElmer FL8500). The results show that the maximum excitation wavelength of the solution is at 342 nm, and the maximum emission wavelength is in the green region at 513 nm.
[0062] Two 5 mg samples of the silver cluster material 1 prepared in Example 1 were sequentially dispersed in 20 mL H2O / DMF mixed solvents with water volumes of 0% and 90% (both 20 mL). The emission spectra were obtained using a Hitachi F-4600 fluorescence spectrophotometer. At an excitation wavelength of 350 nm, the silver cluster material dissolved in pure DMF (f… w The solution containing 0% (0%) showed no luminescence, but exhibited significant emission characteristics when dispersed in a mixed solvent of H2O / DMF containing 90% water, a poor solvent.
[0063] Take 5 mg of the silver cluster material 1 prepared in Example 1 and disperse it in 20 mL of H2O / DMF mixed solvent with a water volume fraction of 90%. The particle size distribution of the silver cluster material in the mixed solvent was determined by dynamic light scattering using a Malvern laser particle size analyzer (model Nano ZS90). Figure 5 As shown in the figure, the particle size in the solution is mainly concentrated in the range of ~745 nm, indicating that as the volume fraction of the undesirable solvent water increases, the silver cluster material aggregates and forms large-sized aggregates, while the luminescence intensity is significantly enhanced. This confirms that the silver cluster material has a significant aggregation-induced emission enhancement (AIE) effect.
[0064] Figure 6 Images of the silver cluster material 1 prepared in Example 1 under natural light (left image) and 365nm ultraviolet light (right image) show that the crystalline product exhibits significant luminescence.
[0065] Figure 7 The excitation spectrum of the silver cluster material prepared in Example 1 (instrument model: Edinburgh FLS1000) shows that its maximum excitation wavelength is 372 nm.
[0066] Figure 8The emission spectra of the silver cluster material prepared in Example 1 in dissolved pure DMF (dissolved concentration of 250 μg / mL, denoted as Solution 1) and in its crystalline state are shown (instrument model: Edinburgh FLS1000). At an excitation wavelength of 370 nm, the silver cluster material in solution showed no emission, while the crystalline state exhibited significant emission, with the maximum emission wavelength located in the blue light region at 478 nm, indicating that the silver cluster material has a significant crystallization-induced emission enhancement (CIE) effect.
[0067] Figure 9 The luminescence decay curve and lifetime fitting curve of the silver cluster material prepared in Example 1 (instrument model: Edinburgh FLS1000) show that its crystal product has a microsecond-level luminescence lifetime of up to 7.25 μs.
[0068] Figure 10 The luminescence quantum yield test diagram of the silver cluster compound material prepared in Example 1 (instrument model: Edinburgh FLS1000) confirms that the luminescence quantum yield of the crystal product is as high as 40.75%.
[0069] Figure 11 This is a schematic diagram of the CH…F hydrogen bond interactions in the unit cell structure of the silver cluster material prepared in Example 1. The interaction distance is represented by dashed lines, and the numbers represent bond lengths (units). It can be seen that the counter ion SbF6 — Strong CH…F hydrogen bond interactions exist between the hydrogen atoms of the neighboring BDPB ligand and the CH2Cl2 solvent molecule, indicating that there are strong non-covalent interactions (CH…F hydrogen bond interactions) in the internal / external structure of the silver cluster material. By restricting intramolecular / intermolecular motion, nonradiative transition pathways are effectively suppressed, thereby achieving the dual characteristics of aggregation-induced enhanced luminescence (AIE) and crystallization-induced enhanced luminescence (CIE).
[0070] Those skilled in the art should understand that the above descriptions are merely several specific embodiments of the present invention, and not all embodiments. It should be noted that many modifications and improvements can be made by those skilled in the art, and all modifications or improvements not exceeding the scope of the claims should be considered within the protection scope of the present invention.
Claims
1. A silver cluster compound material, characterized in that, The chemical formula of the silver cluster material is C. 62 H 52 AgCl4P4SbF6, abbreviated as Ag(BDPB)2SbF6·2CH2Cl2, is a silver cluster material belonging to the monoclinic crystal system; its space group is P21 / c. α=90°, β=90.782(2)°, γ=90°, The molecular weight is 1406.33 Da, and BDPB is 1,2-bis(diphenylphosphine)benzene, with the following structural formula:
2. The silver cluster compound material according to claim 1, characterized in that, The silver cluster material contains one Ag atom, two BDPB organic ligands, and one counterion SbF6. — And 2 CH2Cl2 solvent molecules.
3. A method for preparing the silver cluster compound material according to claim 1 or 2, characterized in that, Includes the following steps: S1. Dissolve silver hexafluoroantimonate and phosphine ligands in a mixed solvent of dichloromethane and methanol, and stir until the mixture is homogeneous; S2. Add sodium borohydride aqueous solution to the obtained mixture and react in the dark at room temperature. The solution first changes from colorless to brown, and finally turns back into a colorless solution. Add distilled water to the colorless solution to remove water-soluble impurities, then add excess n-hexane for washing and centrifugation to obtain crude product. S3. Dissolve the crude product in dichloromethane, introduce diethyl ether into the solution for gas-phase diffusion to induce crystal formation, collect the crystals and dry them to obtain the silver cluster material.
4. The method for preparing the silver cluster compound material according to claim 3, characterized in that, The molar ratio of silver hexafluoroantimonate, phosphine ligand and sodium borohydride is 1:(1-1.6):(4.4-7.2).
5. The method for preparing the silver cluster compound material according to claim 1, characterized in that, In step S1, dichloromethane and methanol are mixed in a volume ratio of (6-9):1 to form a mixed solvent.
6. The method for preparing the silver cluster compound material according to claim 3, 4, or 5, characterized in that, The concentration of silver hexafluoroantimonate in the mixed solvent in step S1 is 0.005-0.085 mmol / mL.
7. The method for preparing the silver cluster compound material according to claim 3, 4, or 5, characterized in that, The phosphine ligand in step S1 is 1,2-bis(diphenylphosphine)benzene; in step S2, the reaction is carried out in the dark at room temperature for 8-14 hours.
8. The application of the silver cluster material according to claim 1 or 2 in aggregation-induced emission and crystallization-induced emission.
9. The application of the silver cluster compound material according to claim 6 in aggregation-induced emission and crystallization-induced emission, characterized in that, The application process of aggregation-induced emission is as follows: equal amounts of silver cluster material were dissolved in pure DMF and a 90% water-volume H2O / DMF mixed solvent, respectively, with a concentration of 250 μg / mL, and were labeled as solution 1 and solution 2, respectively; the emission peak intensities of solution 1 and solution 2 were compared using a light emission spectrometer, and the size distribution of the silver cluster material in solution 2 was measured using a laser particle size analyzer to verify the aggregation-induced emission performance of the silver cluster material.
10. The application of the silver cluster compound material according to claim 8 in aggregation-induced emission and crystallization-induced emission, characterized in that, The application process of crystallization-induced luminescence is as follows: The silver cluster material is dissolved in pure DMF to form a silver cluster material solution with a concentration of 250 μg / mL, which is denoted as solution 1; the luminescence quantum yield and emission peak intensity of the silver cluster material are tested and compared with the emission peak intensity of solution 1 to verify the crystallization-induced luminescence performance of the silver cluster material.