Chiral silver palladium nanoclusters, preparation method and application thereof
By preparing chiral silver-palladium nanoclusters, the problem of constructing precisely structured nanoclusters that combine aggregation-induced emission and circular polarization emission in existing technologies has been solved, achieving high-efficiency optical performance and enhanced luminescence.
Patent Information
- Application Number
- CN202510203909.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-24
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2045-02-24
AI Technical Summary
Existing technologies struggle to construct chiral metal nanoclusters that possess both aggregation-induced emission and circularly polarized emission properties, and materials with precise structures are rarely reported.
Chiral silver-palladium nanoclusters with the chemical formula C174H180Ag14Cl4P12Pd, consisting of 14 Ag atoms, 1 Pd atom, 6 chiral R-BDPP/S-BDPP organic ligands, and 4 Cl halogen ligands, were synthesized using a simple room-temperature method to produce precisely structured nanoclusters, which were then induced to form crystals by gas-phase diffusion.
Atomically precise structures of chiral silver-palladium nanoclusters were achieved. These nanoclusters are small in size and monodisperse, exhibiting significant chiral optical activity and circular dichroism signals. They also possess aggregation-induced emission and circularly polarized emission characteristics, with a significantly enhanced emission peak intensity.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the cross field of nanomaterials and coordination chemistry, and particularly relates to a chiral silver-palladium nanocluster, a preparation method thereof and application thereof in aggregation-induced emission and circularly polarized luminescence. BACKGROUND
[0002] Chiral materials with circularly polarized luminescence (CPL) characteristics have wide application prospects in three-dimensional holographic display, optical data storage, optoelectronic devices, biological imaging and optical quantum information processing. In recent years, chiral metal nanoclusters are regarded as a new type of circularly polarized luminescence functional material due to their excellent optical performance and high degree of adjustability of geometric / electronic structure. From the actual application demand, it is particularly important to develop solid-state CPL materials with high luminescent efficiency. However, the interaction between the excited states of metal nanoclusters in the aggregated state often leads to non-radiative energy transition, resulting in aggregation-caused quenching (ACQ). On the contrary, the concept of aggregation-induced emission (AIE) provides a new strategy for the design of strong luminescent performance solid-state CPL materials. Specifically, the luminescence of metal nanoclusters is enhanced due to the restriction of vibration or rotation within / inter the clusters in the aggregated state. Therefore, the preparation of chiral metal nanocluster materials with both AIE properties and CPL characteristics not only broadens the application range of metal nanoclusters, but also plays an important role in many fields.
[0003] Although various strategies have been developed to construct chiral metal nanocluster materials, there are few reports on metal nanoclusters with both AIE properties and CPL characteristics and precise structure, mainly because the three characteristics of precise structure, aggregation-induced emission property and circularly polarized luminescence property need to be combined into one material, which requires multi-dimensional fine adjustment of the structure of metal clusters. How to construct metal nanoclusters with both AIE properties and CPL characteristics and precise structure has become a problem to be solved. SUMMARY
[0004] In order to solve the above problems in the background art, one of the purposes of the present application is to provide a chiral silver-palladium nanocluster, which is precise in structure and has both aggregation-induced emission and circularly polarized luminescence performance.
[0005] To achieve the above-mentioned purposes, the following technical solutions are adopted in the present application. A chiral silver-palladium nanocluster, the chemical formula of which is C 174 H 180 Ag 14 Cl4P 12 Pd, which is composed of 14 Ag atoms, 1 Pd atom, 6 chiral R-BDPP / S-BDPP organic ligands and 4 Cl halogen ligands, and is abbreviated as Ag14 Pd(R / S-BDPP)6Cl4 or R / S-Ag 14 Pd; wherein, Ag 14 Pd(S-BDPP)6Cl4 or S-Ag 14 Pd belongs to monoclinic system, chiral space group is P21, α = 90°, β = 109.745(3)°, γ = 90°, The molecular weight is 4401.19 Da;
[0006] The organic ligand R-BDPP is (2R, 4R)-bis (diphenylphosphine) pentane, and the organic ligand S-BDPP is (2S, 4S)-bis (diphenylphosphine) pentane, and the structural formula is as follows:
[0007]
[0008] As a further description of the chiral silver-palladium nanocluster structure:
[0009] Preferably, the chiral silver-palladium nanocluster contains an icosahedral cluster core composed of 12 silver atoms and one palladium atom, and the icosahedral cluster core is protected by 6 chiral R-BDPP / S-BDPP organic ligands.
[0010] The second object of the present application is to provide a preparation method of the chiral silver-palladium nanocluster as described in any one of the above, comprising the following steps:
[0011] S1, dissolving silver trifluoromethanesulfonate, palladium acetate and chiral phosphine ligand in a mixed solvent of dichloromethane and methanol, adding sodium borohydride aqueous solution, reacting at room temperature in the dark for 10-16h, then removing water-soluble impurities in the solution by adding distilled water, and precipitating the crude product with diethyl ether;
[0012] S2, dissolving the crude product in dichloromethane, introducing diethyl ether into the solution to induce crystal formation by gas phase diffusion, collecting and air-drying the crystal product, and obtaining the chiral silver-palladium nanocluster.
[0013] As a further improvement of the preparation method of the chiral silver-palladium nanocluster:
[0014] Preferably, the dichloromethane and methanol in step S1 are mixed in a volume ratio of (5-6):1 to form a mixed solvent.
[0015] Preferably, in step S1, the chiral phosphine ligand is (2R, 4R)-2, 4-bis (diphenylphosphine) pentane or (2S, 4S)-2, 4-bis (diphenylphosphine) pentane.
[0016] Preferably, in step S1, the molar mass ratio of silver trifluoromethanesulfonate, palladium acetate, chiral phosphine ligand and sodium borohydride contained in the aqueous sodium borohydride solution is 1:(0.1-0.4):(1-1.6):(1-2).
[0017] Preferably, in step S1, the silver trifluoromethanesulfonate has a solubility concentration of 0.008-0.01 mmol / ml in the mixed solvent of dichloromethane and methanol.
[0018] A third object of the present application is to provide the application of the chiral silver-palladium nanocluster described in any of the above to aggregation-induced emission and circularly polarized luminescence.
[0019] As a further improvement of the application of the chiral silver-palladium nanocluster to aggregation-induced emission and circularly polarized luminescence:
[0020] Preferably, the application process of aggregation-induced emission is as follows: 1 mg of chiral silver-palladium nanocluster is dispersed in N,N-dimethylformamide DMF, and at the same time, 1 mg of chiral silver-palladium nanocluster is dispersed in a mixed solvent of water with a volume fraction of 95% and N,N-dimethylformamide DMF, both of which are configured into a solution with a concentration of 200 ug / mL. The emission peak intensity change of the two solutions is measured by a fluorescence spectrometer, and the size distribution of the nanoclusters in the two solutions is measured by a transmission electron microscope and a laser particle size analyzer.
[0021] Preferably, the application process of circularly polarized luminescence is as follows: 1 mg of chiral silver-palladium nanocluster is dissolved in dichloromethane to configure a solution with a concentration of 0.2 mg / mL, which is tested by a circular dichroism spectrometer; at the same time, 1 mg of chiral silver-palladium nanocluster is dissolved in dichloromethane to configure a solution with a concentration of 1.0 mg / mL, which is tested by a circularly polarized fluorescence spectrometer.
[0022] The present application has the following beneficial effects compared with the prior art:
[0023] 1) The present application provides a chiral silver-palladium nanocluster, the chemical formula of which is C 174 H 180 Ag 14 Cl4P 12 Pd, which has an atomic-level precise structure, a small size (~1.82 nm) and good monodispersity. The chiral nanocluster exhibits good chiral optical activity, with an emission peak at 662 nm, and has significant chiral optical activity characteristics and circular dichroism signals, and also has the two characteristics of aggregation-induced emission and circularly polarized luminescence, with an absorption asymmetry factor and an emission asymmetry factor as high as 8.2 x 10 -4 and 2.2 x 10 -3 .
[0024] 2) The present application provides a preparation method of silver-palladium nanoclusters, which has simple synthesis method, mild reaction condition, low cost, no need for calcination, and only needs to select easily available silver salt, (2R,4R)-2,4-bis(diphenylphosphino)pentane or (2S,4S)-2,4-bis(diphenylphosphino)pentane, palladium salt and sodium borohydride, so that the chiral silver-palladium nanoclusters can be prepared simply and quickly by one-pot method at room temperature. BRIEF DESCRIPTION OF DRAWINGS
[0025] Figure 1 Structure diagram of the chiral silver-palladium nanoclusters prepared in Examples 1-2 of the present application;
[0026] Figure 2 UV absorption spectrum of the chiral silver-palladium nanocluster solution prepared in Example 1-4 of the present application;
[0027] Figure 3 Electrospray high-resolution mass spectrum of the chiral silver-palladium nanoclusters prepared in Example 1-4 of the present application;
[0028] Figure 4 Particle size distribution diagram of the chiral silver-palladium nanoclusters prepared in Example 1-4 of the present application;
[0029] Figure 5 Excitation spectrum and emission spectrum diagram of the chiral silver-palladium nanoclusters prepared in Example 1-4 of the present application;
[0030] Figure 6 Emission spectrum diagram of the chiral silver-palladium nanoclusters prepared in Example 1-4 of the present application dispersed in mixed solvents of water and DMF in different proportions, wherein the volume fraction of water is f=0 and 95%, respectively;
[0031] Figure 7 Particle size distribution diagram of the chiral silver-palladium nanoclusters prepared in Example 1-4 of the present application dispersed in mixed solvents of water and DMF with a volume fraction of pure water of 95%;
[0032] Figure 8 Circular dichroism spectrum (CD) diagram of the chiral silver-palladium nanocluster solution prepared in Example 1-4 of the present application.
[0033] Figure 9 Absorption asymmetry factor diagram of the chiral silver-palladium nanocluster solution prepared in Example 1-4 of the present application.
[0034] Figure 10 Circularly polarized luminescence spectrum (CPL) diagram of the chiral silver-palladium nanocluster solution prepared in Example 1-4 of the present application.
[0035] Figure 11 Emission asymmetry factor diagram of the chiral silver-palladium nanocluster solution prepared in Example 1-4 of the present application. DETAILED DESCRIPTION
[0036] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application 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 in the present application without creative labor shall fall within the scope of protection of the present application.
[0037] Embodiment 1
[0038] The embodiment provides a preparation method of a chiral silver-palladium nanocluster, comprising the following steps:
[0039] S1, silver trifluoromethanesulfonate (15 mg, 0.058 mmol), palladium acetate (3 mg, 0.013 mmol) and (2S, 4S)-2, 4-bis (diphenylphosphine) pentane (30 mg, 0.068 mmol) are dissolved in a mixed solvent of 6 mL of dichloromethane and 1 mL of methanol, 1 mL of sodium borohydride solution (3 mg / mL, containing 0.079 mmol of sodium borohydride) is added, and the reaction is carried out for 16 h under light-proof conditions, followed by removing water-soluble impurities in the solution by adding distilled water, and precipitating the crude product with diethyl ether;
[0040] The molar mass ratio of the silver trifluoromethanesulfonate, the palladium acetate, the chiral phosphine ligand and the sodium borohydride contained in the sodium borohydride aqueous solution is 1:0.22:1.17:1.36.
[0041] S2, the crude product is dissolved in dichloromethane, diethyl ether is introduced into the solution to induce crystal formation by gas-phase diffusion, and the crystal product is collected and dried to obtain the chiral silver-palladium nanocluster.
[0042] Embodiment 2
[0043] The embodiment provides a preparation method of a chiral silver-palladium nanocluster, comprising the following steps:
[0044] S1, silver trifluoromethanesulfonate (15 mg, 0.058 mmol), palladium acetate (3 mg, 0.013 mmol) and (2S, 4S)-2, 4-bis (diphenylphosphine) pentane (30 mg, 0.068 mmol) are dissolved in a mixed solvent of 6 mL of dichloromethane and 1 mL of methanol, 1 mL of sodium borohydride solution (3 mg / mL, containing 0.079 mmol of sodium borohydride) is added, and the reaction is carried out for 16 h under light-proof conditions, followed by removing water-soluble impurities in the solution by adding distilled water, and precipitating the crude product with diethyl ether;
[0045] The molar mass ratio of the silver trifluoromethanesulfonate, the palladium acetate, the chiral phosphine ligand and the sodium borohydride contained in the sodium borohydride aqueous solution is 1:0.22:1.17:1.36.
[0046] S2, dissolve the crude product in dichloromethane, and pass ether into the solution to induce crystal formation by gas-phase diffusion, collect and air-dry the crystal product to obtain the chiral silver-palladium nanocluster.
[0047] Example 3
[0048] The embodiment provides a preparation method of a chiral silver-palladium nanocluster, and the method comprises the following steps:
[0049] S1, dissolve silver trifluoromethanesulfonate (15 mg, 0.058 mmol), palladium acetate (1.3 mg, 0.0058 mmol) and (2R, 4R)-2, 4-bis (diphenylphosphine) pentane (25.5 mg, 0.058 mmol) in a mixed solvent of 5 mL of dichloromethane and 1 mL of methanol, add 1 mL of sodium borohydride solution (2.2 mg / mL, containing 0.058 mmol of sodium borohydride), react for 14 h under light-proof conditions, then remove water-soluble impurities in the solution by adding distilled water, and precipitate the crude product by using ether;
[0050] The molar mass ratio of the silver trifluoromethanesulfonate, the palladium acetate, the chiral phosphine ligand and the sodium borohydride contained in the sodium borohydride aqueous solution is 1:0.1:1:1.
[0051] S2, dissolve the crude product in dichloromethane, and pass ether into the solution to induce crystal formation by gas-phase diffusion, collect and air-dry the crystal product to obtain the chiral silver-palladium nanocluster.
[0052] Example 4
[0053] The embodiment provides a preparation method of a chiral silver-palladium nanocluster, and the method comprises the following steps:
[0054] S1, dissolve silver trifluoromethanesulfonate (15 mg, 0.058 mmol), palladium acetate (1.3 mg, 0.0058 mmol) and (2R, 4R)-2, 4-bis (diphenylphosphine) pentane (25.5 mg, 0.058 mmol) in a mixed solvent of 5 mL of dichloromethane and 1 mL of methanol, add 1 mL of sodium borohydride solution (2.2 mg / mL, containing 0.058 mmol of sodium borohydride), react for 14 h under light-proof conditions, then remove water-soluble impurities in the solution by adding distilled water, and precipitate the crude product by using ether;
[0055] The molar mass ratio of the silver trifluoromethanesulfonate, the palladium acetate, the chiral phosphine ligand and the sodium borohydride contained in the sodium borohydride aqueous solution is 1:0.1:1:1.
[0056] S2, dissolve the crude product in dichloromethane, and pass ether into the solution to induce crystal formation by gas-phase diffusion, collect and air-dry the crystal product to obtain the chiral silver-palladium nanocluster.
[0057] The chiral silver-palladium nanoclusters of the present invention prepared in Examples 1-4 were further characterized as follows:
[0058] (1) Crystal structure determination
[0059] Under nitrogen protection and a low temperature of 193 K, the crystal products from Examples 1-2 were selected under a microscope and tested using a single-crystal X-ray diffractometer (Bruker D8 Venture). The diffracted crystals were then monochromated using a graphite monochromator. Cu-Kα diffraction was performed, and diffraction data were collected using the ω-scan method. The single-crystal structure was determined directly using the SHELXL-97 software program, with the least squares F2 method used for refinement and the SADABS program used for empirical absorption correction. First, the positions of all non-hydrogen atoms were determined and anisotropic corrections were made. All Ag, Pd, P, Cl, and C atoms were directly identified. The refinement of the hydrogen atom positions in the molecule was obtained using isotropic calculations. Detailed crystal measurement data are shown in Table 1. Figure 1 As shown, the results indicate that the molecular formula of the chiral silver-palladium nanoclusters in Examples 1-2 after analysis is C 174 H 180 Ag 14 Cl4P 12 Pd, abbreviated as Ag 14 Pd(S-BDPP)6Cl4 or S-Ag 14 Pd; its precise structure contains an icosahedral cluster core consisting of 12 silver atoms and one palladium atom, protected by 6 S-BDPP chiral ligands.
[0060] Single-crystal X-ray diffraction was used to measure the Ag crystals prepared in Examples 3-4. 14 Pd(R-BDPP)6Cl4 or R-Ag 14 Pd chiral nanoclusters, with cell parameters of: α=90°, β=109.70°, γ=90°, R-Ag 14 Pd and S-Ag 14 Pd's unit cell parameters (Table 1), UV-Vis absorption spectrum ( Figure 2 ) and electrospray high-resolution mass spectrometry ( Figure 3 By comparison, it can be determined that the S-Ag prepared in Examples 1-2 is superior. 14 Pd nanoclusters have identical structures and are chiral enantiomers of each other. Specifically, Figure 2 The chiral silver-palladium nanoclusters prepared in Examples 1-4 were dissolved in dichloromethane and tested using a UV8000 (METASH) ultraviolet-visible absorption spectrometer. R-Ag 14Pd and S-Ag 14 The UV absorption peak position of Pd is consistent, indicating that the structures of the two are the same.
[0061] Figure 3 The chiral nanoclusters prepared in the above examples 1-2 and example 3-4 were respectively dissolved in methanol and tested by electrospray high-resolution mass spectrometry (model Xevo G3 QTOF) in positive ion mode, the S-Ag prepared in example 1-2 14 The mass spectrometry peak of Pd is at m / z 2201.75 Da, corresponding to [Ag 14 Pd(S-BDPP)6Cl4] 2+ ; the R-Ag prepared in example 3-4 14 The mass spectrometry peak of Pd is at m / z 2201.76 Da, corresponding to [Ag 14 Pd(R-BDPP)6Cl4] 2+ ; S-Ag 14 Pd and R-Ag 14 The mass spectrometry peak position and molecular weight of Pd are consistent, further proving that the two are chiral enantiomers of each other.
[0062] Table 1 main crystallographic parameters
[0063]
[0064]
[0065] R1 = ∑||Fo|-|Fc|| / ∑|Fo|. wR2 = [∑w(F o 2 -F c 2 ) 2 / ∑w(F o 2 ) 2 ] 1 / 2
[0066] (2) Application of the chiral silver-palladium nanocluster of the present application in aggregation-induced emission and circularly polarized luminescence
[0067] The circularly polarized luminescence application includes the following process: 1 mg of the chiral silver-palladium nanocluster is dissolved in dichloromethane to prepare a solution with a concentration of 0.2 mg / mL, and tested by a circular dichroism spectrometer; at the same time, 1 mg of the chiral silver-palladium nanocluster is dissolved in dichloromethane to prepare a solution with a concentration of 1.0 mg / mL, and tested by a circularly polarized fluorescence spectrometer.
[0068] The aggregation-induced emission application includes the following process: 1 mg of chiral silver palladium nanoclusters is dispersed in N,N-dimethylformamide DMF, while 1 mg of chiral silver palladium nanoclusters is dispersed in a mixed solvent of water / N,N-dimethylformamide DMF with a water volume fraction of 95%, both of which are configured into a solution with a concentration of 200 ug / mL, and the water volume fraction is f=0% and 95% respectively. The emission peak intensity of the two solutions is measured by a fluorescence spectrometer, and the size distribution of the particles in the solution is measured by transmission electron microscopy and a laser particle size analyzer.
[0069] Figure 4 The chiral silver palladium nanoclusters prepared in the above embodiments 1-4 are dissolved in DMF, and then dropped on a copper mesh and dried to perform transmission electron microscopy TEM (Hitachi HT7700) test, and the results show that the size of the chiral silver palladium nanoclusters is small and uniform, and the average size is 1.82 nm.
[0070] Figure 5 The chiral silver palladium nanoclusters prepared in the above embodiments 1-4 are dissolved in DMF, and then dropped on a copper mesh and dried to perform transmission electron microscopy TEM (Hitachi HT7700) test, and the results show that the size of the chiral silver palladium nanoclusters is small and uniform, and the average size is 1.82 nm. 14 The maximum excitation wavelength of the Pd(R / S-BDPP)6Cl4 nanoclusters is 406 nm, and the maximum emission wavelength is 662 nm, which belongs to the red light region.
[0071] Figure 6 The chiral silver palladium nanoclusters prepared in the above embodiments 1-4 are dispersed in a mixed solvent of water / DMF with a water volume fraction of 95% and a single DMF solvent in an equal amount, and both are configured into a solution with a solution concentration of 200 ug / mL. A light source with a wavelength of 430 nm is used for excitation, and the emission peak intensity of the two solutions is measured by a fluorescence spectrophotometer. The results show that the emission peak intensity of the chiral silver palladium nanoclusters added to the mixed solvent of water / DMF with a water volume fraction of 95% is 4.5 times that of the single DMF solvent. Under the irradiation of a 365 nm ultraviolet lamp, the luminescence intensity of the two solutions is obviously compared. The above results all show that the chiral silver palladium nanoclusters have the property of aggregation-induced emission.
[0072] Figure 7 The chiral silver palladium nanoclusters prepared in the above embodiments 1-4 are dispersed in a mixed solvent of water / DMF with a water volume fraction of 95%, and a Malvern laser particle size analyzer (model Nano ZS90) is used to measure the size distribution of the particles in the solution by dynamic light scattering. The results show that the average size of the chiral silver palladium nanoclusters is 852 nm, which indicates that the chiral silver palladium nanoclusters have undergone an aggregation process in the mixed solvent of water / DMF with a water volume fraction of 95%, so the average particle size of the chiral silver palladium nanoclusters increases from 1.82 nm Figure 4 ) to 852 nm. Combined with the above results, it can be seen that the chiral silver palladium nanoclusters have the property of aggregation-induced emission. Figure 6It can be further confirmed that the luminescence enhancement phenomenon of the chiral silver palladium nanoclusters in the mixed solvent of water / DMF with a water volume fraction of 95% is mainly attributed to the aggregation behavior of the chiral silver palladium nanoclusters. Specifically, the aggregation inhibits the motion between the chiral silver palladium nanoclusters, thereby reducing the non-radiative transition and enhancing the luminescence performance of the chiral silver palladium nanoclusters.
[0073] Figure 8 The chiral silver palladium nanoclusters prepared in the above-mentioned Examples 1-4 were dissolved in dichloromethane to prepare a solution with a concentration of 0.2 mg / mL, and tested by a circular dichroism spectrometer (model JASCO J-1500). The results show that the chiral silver palladium nanoclusters have significant chiral optical activity, and the characteristic is the mirror-symmetric circular dichroism signal.
[0074] Figure 9 The chiral silver palladium nanoclusters prepared in the above-mentioned Examples 1-4 were dissolved in dichloromethane to prepare a solution with a concentration of 0.2 mg / mL, and tested by a circular dichroism spectrometer (model JASCO J-1500). The results show that the chiral silver palladium nanoclusters have significant chiral optical activity, and the characteristic is the mirror-symmetric circular dichroism signal. abs , is 8.2 x 10 -4 .
[0075] Figure 10 The chiral silver palladium nanoclusters prepared in the above-mentioned Examples 1-4 were dissolved in dichloromethane to prepare a solution with a concentration of 1.0 mg / mL, and tested by a circular polarization fluorescence spectrometer (model JASCO CPL-300). The results show that the chiral silver palladium nanoclusters have obvious mirror-symmetric circular polarization luminescence signals.
[0076] Figure 11 The chiral silver palladium nanoclusters prepared in the above-mentioned Examples 1-2 were dissolved in dichloromethane to prepare a solution with a concentration of 1.0 mg / mL, and tested by a circular polarization fluorescence spectrometer (model JASCO CPL-300). The results show that the chiral silver palladium nanoclusters have a larger circular polarization luminescence asymmetry factor g lum , of 2.2 x 10 -3 .
[0077] Those skilled in the art should understand that the above-mentioned is only several specific embodiments of the present application, not all embodiments. It should be noted that many modifications and improvements can also be made by those skilled in the art, and all modifications or improvements that do not exceed the scope of the claims should be considered as the protection scope of the present application.
Claims
1. A chiral silver palladium nanocluster, characterized in that, The molecular formula of the chiral silver-palladium nanocluster cation body structure is [C 174 H 180 Ag 14 Cl4P 12 Pd] 2+ , which is composed of 14 Ag atoms, 1 Pd atom, 6 chiral R-BDPP / S-BDPP organic ligands and 4 Cl halogen ligands, and the molecular formula of the cation body structure is abbreviated as [Ag 14 Pd(R / S-BDPP)6Cl4] 2+ , or R / S-Ag 14 Pd; wherein, [Ag 14 Pd(S-BDPP)6Cl4] 2+ , or S-Ag 14 Pd belongs to a monoclinic system, and the chiral space group is P21, α = 90°, β = 109.745(3)°, γ = 90°, The molecular weight is 4401.19 Da; The organic ligand R-BDPP is (2R,4R)-bis(diphenylphosphino)pentane, and the organic ligand S-BDPP is (2S,4S)-bis(diphenylphosphino)pentane, and the structural formula is as follows:
2. A method of preparing the chiral silver palladium nanocluster of claim 1, wherein, The method comprises the following steps: S1, dissolving silver trifluoromethanesulfonate, palladium acetate and a chiral phosphine ligand in a mixed solvent of dichloromethane and methanol, adding an aqueous sodium borohydride solution, and reacting at room temperature for 10-16 hours in the dark, then removing water-soluble impurities in the solution by adding distilled water, and precipitating the crude product with diethyl ether; S2, dissolving the crude product in dichloromethane, introducing diethyl ether into the solution to induce crystal formation by gas-phase diffusion, collecting and air-drying the crystal product, thereby obtaining the chiral silver-palladium nanocluster.
3. The method for preparing chiral silver-palladium nanoclusters according to claim 2, characterized in that, In step S1, the dichloromethane and methanol are mixed in a volume ratio of (5-6):1 to form a mixed solvent.
4. The method for preparing chiral silver-palladium nanoclusters according to claim 2, characterized in that, In step S1, the chiral phosphine ligand is (2R,4R)-2,4-bis(diphenylphosphino)pentane or (2S,4S)-2,4-bis(diphenylphosphino)pentane.
5. The method for preparing chiral silver-palladium nanoclusters according to claim 2, characterized in that, In step S1, the molar mass ratio of silver trifluoromethanesulfonate, palladium acetate, chiral phosphine ligand and sodium borohydride contained in the aqueous sodium borohydride solution is 1:(0.1-0.4):(1-1.6):(1-2).
6. The method for preparing chiral silver-palladium nanoclusters according to claim 2, characterized in that, In step S1, the solubility concentration of silver trifluoromethanesulfonate in the mixed solvent of dichloromethane and methanol is 0.008-0.01 mmol / ml.
7. The chiral silver-palladium nanocluster of claim 1 is used in the applications of aggregation-induced emission and circularly polarized luminescence.
8. Use of the chiral silver palladium nanoclusters according to claim 7 for aggregation induced emission and circularly polarized luminescence. The application process of aggregation-induced emission is as follows: 1 mg of the chiral silver-palladium nanocluster is dispersed in N,N-dimethylformamide DMF, and 1 mg of the chiral silver-palladium nanocluster is dispersed in a mixed solvent of water with a volume fraction of 95% and N,N-dimethylformamide DMF, both of which are configured into a solution with a concentration of 200 ug / mL, the emission peak intensity changes of the two solutions are measured by a fluorescence spectrometer, and the size distribution of the nanoclusters in the two solutions is measured by a transmission electron microscope and a laser particle size analyzer.
9. Use of the chiral silver palladium nanocluster according to claim 7 for aggregation induced emission and circularly polarized luminescence. The application process of circularly polarized luminescence is as follows: 1 mg of the chiral silver-palladium nanocluster is dissolved in dichloromethane to configure a solution with a concentration of 0.2 mg / mL, which is tested by a circular dichroism spectrometer; meanwhile, 1 mg of the chiral silver-palladium nanocluster is dissolved in dichloromethane to configure a solution with a concentration of 1.0 mg / mL, which is tested by a circularly polarized fluorescence spectrometer.