Preparation method and application of a zero-dimensional two-nuclear magnetic fluorescent bifunctional dysprosium-based complex

Abstract

The present invention discloses a preparation method and application of a zero-dimensional binary magnetic fluorescent bifunctional dysprosium complex, wherein the structural formula of the dysprosium complex is [Dy(bbpen)(dppBO2)2](BPh4)·4MeCN. The present invention selects a high-performance single-ion magnet primitive and a fluorescently active phosphine oxide ligand to construct a zero-dimensional binary magnetic fluorescent bifunctional dysprosium complex. Due to the classic pentagonal bipyramidal single-ion magnet primitive [Dy III (bbpen)] + The presence of makes the complex maintain the significant magnetic anisotropy of dysprosium ions, and the selected phosphine oxide ligand has multiple conjugated π bonds showing antenna effect, so the obtained product has both magnetic and fluorescent dual functional properties. Theoretical calculation results also show that the Cramer level of the dysprosium-based complex of the present invention matches its fluorescence transition energy level. Therefore, the dysprosium-based complex of the present invention has broad application prospects in the preparation of magnetic and / or fluorescent materials.

Description

Technical Field

[0001] The invention relates to the technical field of multifunctional dysprosium complexes, and in particular to a preparation method and application of a zero-dimensional binuclear magnetic fluorescent bifunctional dysprosium-based complex. Background Art

[0002] Due to the special electronic configuration, rare earths show rich energy level transitions, significant atomic magnetic moments, and strong spin-orbit coupling and other physical and chemical characteristics. They have shown attractive application prospects in the fields of optics, electricity, magnetism, aerospace, military, agriculture, biomedicine, etc., and play an indispensable role in modern scientific and technological applications, and are known as "industrial vitamins". Rare earths have unfilled 4f and 5d electrons that are shielded by external 5s and 5p, so they have rich electronic energy levels and long excited state lifetimes. There are more than 200,000 energy level transitions, which can produce rich absorption and emission. Because they are insensitive to external fields, the energy levels and spectra of rare earths in solids have atomic state characteristics. The spectrum of ff transition is sharp and has high color purity, and the transition from 4f shell to other configurations is a band spectrum, so rare earths are very suitable for luminescent materials. The effect of the crystal field on the 4f electrons of rare earth ions is much smaller than the Coulomb effect between electrons, and also much smaller than the spin-orbit effect of 4f electrons. Rare earth ions will split their energy levels under the action of the ligand field. The form and size of the splitting depends on the strength and symmetry of the crystal field and is very sensitive to the coordination environment. Therefore, they are very suitable as spin carriers to construct magnetic materials. Strong spin-orbit coupling can produce strong magnetic anisotropy. On the other hand, the abundant unpaired 4f electrons give it a large M J state, which makes rare earth ions have unique advantages in constructing single-molecule magnets. 3+ With a ground state of 15 / 2, it is equivalent to 5 Mn 4+ The ground state is obtained via ferromagnetic coupling.

[0003] Although rare earth luminescent materials and rare earth single-molecule magnet materials have been extensively studied, there are few studies on dysprosium-based complexes that couple luminescence and magnetism. Magneto-optical dual-functional materials have broad application prospects in magneto-optical storage, magneto-optical sensors, magneto-optical regulation, etc. As a resource-rich country with the largest rare earth reserves, my country needs to increase its in-depth exploration of the unique physical and chemical properties of rare earths in order to achieve efficient utilization of rare earth resources in my country and realize the rapid development of high-tech industries with rare earths as the core. Summary of the invention

[0004] In order to overcome the above defects and shortcomings in the prior art, the present invention provides a preparation method and application of a zero-dimensional binuclear magnetic fluorescent bifunctional dysprosium-based complex.

[0005] The first object of the present invention is to provide a dysprosium-based complex having magnetic and fluorescent dual functions.

[0006] The second object of the present invention is to provide a method for preparing the dysprosium-based complex.

[0007] The third object of the present invention is to provide a dysprosium-based complex prepared by the above-mentioned method for preparing the dysprosium-based complex.

[0008] The fourth object of the present invention is to provide the use of the above-mentioned dysprosium-based complex in the preparation of magnetic and / or luminescent materials.

[0009] Therefore, the present invention claims the following:

[0010] A dysprosium-based complex with magnetic and fluorescent dual functions, wherein the structural formula of the dysprosium-based complex is [Dy(bbpen)(dppBO2)2](BPh4)·4MeCN, wherein (bbpen) 2- is the anion of N, N'-bis(2-hydroxybenzyl)-N, N'-bis(2-pyridylmethyl)ethylenediamine, dppBO2 is 1,4-butanediylbis(diphenylphosphine oxide), (BPh4) - It is the tetraphenylborate ion.

[0011] Preferably, the dysprosium-based complex crystallizes in the triclinic system, belongs to the P-1 space group, and has a unit cell parameter of: α=69.733(2)°, β=88.444(2)°, γ=80.520(2)°,

[0012] A method for preparing a dysprosium-based complex comprises the following steps:

[0013] S1. III (bbpen)NO3], acetonitrile and dichloromethane were fully mixed, and then dppBO2 was added. After mixing well, NaBPh4 was added and mixed again to obtain a mixed solution;

[0014] Said III The structural formula of (bbpen)NO3] is shown in formula (I):

[0015]

[0016] The structural formula of the dppBO2 is shown in formula (II):

[0017]

[0018] Where n = 4;

[0019] S2. The mixed solution is reacted at a constant temperature of 74 to 76°C for 72 to 73 hours, then cooled to 24 to 26°C, the solid-liquid separation is performed to obtain the liquid, and the liquid is allowed to stand at 24 to 26°C for crystallization to obtain the dysprosium-based complex.

[0020] In step S1, the [Dy III [Dy(bbpen)NO3] is “[Dy(bbpen)NO3]” in the prior art “Cyanometallate-Bridged Didysprosium Single-Molecule Magnets Constructed with Single-Ion Magnet Building Block” (DOI: 10.1021 / acs.inorgchem.9b02948, publication date: December 10, 2019), and the preparation method is shown in “Synthesis of [Dy(bbpen)NO3]” in the prior art;

[0021] The dppBO2 is "Tetra-P-phenyl-P, P'-butanediyl-bis-phosphine oxide 4" in the prior art "Understanding the structural properties of ahomologous series of bis-diphenylphosphine oxides" (DOI: 10.1002 / 1521-3765 (20000703) 6: 13 <2338::aid-chem2338> 3.0.co; 2-n, published on August 12, 2000), and the preparation method is shown in the "General procedure" and "Tetra-P-phenyl-P, P'-butanediyl-bis-phosphine oxide 4" (page 2348) in the prior art.

[0022] Preferably, in step S1, the [Dy III The usage ratio of (bbpen)NO3], acetonitrile, dichloromethane, dppBO2 and NaBPh4 is (1~1.4) mg: (1~1.4) mL: (0.6~1.0) mL: 1 mg: (0.4~0.8) mg.

[0023] More preferably, the [Dy III The usage ratio of (bbpen)NO3], acetonitrile, dichloromethane, dppBO2 and NaBPh4 is 1.2mg:1.2mL:0.8mL:1mg:0.6mg.

[0024] Preferably, in step S1, the methods of fully mixing and uniformly mixing are both stirring at 24-26° C. for 10 min.

[0025] The method used in step S2 is a solvent thermal method combined with a room temperature volatilization method.

[0026] Preferably, in step S2, the temperature is 75°C.

[0027] Preferably, in step S2, the mixed solution is heated to 75° C. within 4 hours and then reacted at a constant temperature.

[0028] Preferably, in step S2, the isothermal reaction time is 72 hours.

[0029] Preferably, in step S2, the cooling rate is 4-6°C / h.

[0030] More preferably, the cooling rate is 5°C / h.

[0031] Preferably, in step S2, the method for crystallization is a slow volatilization method, specifically, the liquid is allowed to stand at 24-26° C. to evaporate slowly, and crystals are precipitated after one to two weeks.

[0032] The dysprosium complex prepared by the above preparation method.

[0033] Use of any of the above dysprosium-based complexes in the preparation of magnetic materials and / or fluorescent materials.

[0034] Preferably, the magnetic material is a molecule-based magnetic material, and the fluorescent material is a sharp-line light source fluorescent material.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention discloses a preparation method and application of a binuclear magnetic fluorescent bifunctional dysprosium complex, wherein the structural formula of the dysprosium complex is [Dy(bbpen)(dppBO2)2](BPh4)·4MeCN. The present invention selects a high-performance single-ion magnet primitive and a fluorescently active phosphine oxide ligand to construct a zero-dimensional binuclear magnetic / fluorescent bifunctional dysprosium complex. Due to the classic pentagonal bipyramidal single-ion magnet primitive [Dy III (bbpen)] + The presence of makes the complex maintain the significant magnetic anisotropy of dysprosium ions, and the selected phosphine oxide ligand has multiple conjugated π bonds to produce antenna effects, so the obtained product has both magnetic and fluorescent functional properties. Theoretical calculation results also show that the Cramer level of the dysprosium-based complex of the present invention matches its fluorescence transition energy level. In addition, the construction and preparation of the dysprosium-based complex of the present invention also provides a new synthetic idea and method for obtaining such complexes.

[0037] The magnetic fluorescent bifunctional dysprosium-based complex of the present invention has the following advantages:

[0038] (1) The magnetic fluorescent bifunctional dysprosium-based complex of the present invention has a zero-dimensional binary structure, good stability, outstanding single-molecule magnetic properties and a fine linear fluorescence spectrum characteristic of dysprosium ions, and can be used as a multifunctional magnetic material and / or fluorescent material;

[0039] (2) The preparation method of the magnetic fluorescent bifunctional dysprosium-based complex of the present invention is low-cost and simple to operate. The bifunctional material with high yield and high crystallinity can be prepared through low-temperature solvent thermal reaction and simple room-temperature volatilization, which meets the requirements of green chemistry and is suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Schematic diagram of the synthesis of the dysprosium complex of Example 1.

[0041] Figure 2 The single crystal structure diagram of the dysprosium-based complex of Example 1; (a): the smallest asymmetric unit, (b): the zero-dimensional two-nuclear structure diagram, (c): the stacking diagram of the complex, (d): the central dysprosium ion is in a tetragonal anti-prism coordination configuration. All the structural diagrams omit H atoms for simplicity and clarity.

[0042] Figure 3 This is the infrared spectrum of the dysprosium-based complex of Example 1.

[0043] Figure 4 This is a temperature-dependent magnetic susceptibility curve of the dysprosium-based complex of Example 1 under an external magnetic field of 1 kOe.

[0044] Figure 5 The temperature-dependent magnetization curve (a) and the reduced temperature-dependent magnetization intensity curve (b) of the dysprosium-based complex of Example 1 are shown.

[0045] Figure 6 The temperature-dependent AC magnetic susceptibility diagrams of the dysprosium-based complex of Example 1 at zero external field (a) and 1000 Oe (b), wherein the solid lines serve as indicators.

[0046] Figure 7 The relaxation time distribution diagram of the dysprosium complex in Example 1 under zero field is temperature dependent. The green solid line is the full fitting result in the entire temperature range.

[0047] Figure 8 Graph showing the fluorescence emission and absorption spectra of the dysprosium-based complex of Example 1.

[0048] Fig. 9 The dysprosium complex of Example 1 was prepared at 279.62K (λ ex=312nm) and low temperature 14.55K (λ ex =483.8nm) fluorescence emission spectrum.

[0049] Fig.10 This is the fluorescence lifetime diagram of the dysprosium-based complex of Example 1.

[0050] Fig.11 This is the X-ray powder diffraction pattern of the dysprosium-based complex of Example 1. DETAILED DESCRIPTION

[0051] The present invention is further described below with reference to specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0052] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0053] [Dy III The structural formula of [Dy(bbpen)NO3] is shown in formula (I), which is the “[Dy(bbpen)NO3]” in the prior art “Cyanometallate-Bridged Didysprosium Single-Molecule Magnets Constructed with Single-Ion Magnet Building Block” (DOI: 10.1021 / acs.inorgchem.9b02948, published on December 10, 2019), and the preparation method is shown in the “Synthesis of [Dy(bbpen)NO3]” in the prior art;

[0054]

[0055] The structural formula of dppBO2 used in the embodiment is shown in formula (II), wherein n=4, which is "Tetra-P-phenyl-P, P'-butanediyl-bis-phosphine oxide 4" in the prior art "Understanding the structural properties of a homologous series of bis-diphenylphosphine oxides" (DOI: 10.1002 / 1521-3765(20000703)6:13<2338::aid-chem2338>3.0.co;2-n, published on August 12, 2000), and the preparation method is shown in "General procedure" and "Tetra-P-phenyl-P, P'-butanediyl-bis-phosphine oxide 4" (page 2348) in the prior art.

[0056]

[0057] H2bbpen: N,N'-bis(2-hydroxybenzyl)-N,N'-bis(2-pyridylmethyl)ethylenediamine, CAS No. 138614-53-6;

[0058] NaBPh4: sodium tetraphenylborate, CAS No. 143-66-8;

[0059] Acetonitrile and dichloromethane were of analytical grade and used without further purification.

[0060] Example 1 Synthesis of Dysprosium Complex

[0061] The synthesis diagram of dysprosium complexes is shown in Figure 1 shown.

[0062] Weigh 0.006g[Dy III [(bbpen)NO3] was placed in a polytetrafluoroethylene reactor, 6 mL of acetonitrile and 4 mL of dichloromethane were added, and 0.005 g of dppBO2 was added after stirring for 10 min at 25 °C, and then 0.003 g of NaBPh4 was added after stirring for 10 min and then a solvothermal reaction was carried out. The reaction conditions were as follows: the temperature was raised to 75 °C for 4 h, then kept constant for 72 h, and then dropped to 25 °C at a rate of 5 °C / h. Filtered, the filtrate was placed at 25 °C to evaporate slowly, and after one to two weeks, the solution changed from colorless to light yellow and colorless block crystals were precipitated, which was the dysprosium complex [Dy(bbpen)(dppBO2)2](BPh4)·4MeCN.

[0063] Example 2 Crystal structure determination and characterization

[0064] 1. Experimental Methods

[0065] The size of the sample prepared in Example 1 is 0.105×0.081×0.064 mm. 3 The colorless bulk single crystal product was subjected to structural testing, and the Mo Kα rays were diffracted by a Bruker D8 QUEST single crystal X-ray diffractometer at 150K, and the Mo Kα rays were monochromatized by a graphite monochromator. The diffraction data were collected and processed using the incident light source. All calculations were performed using the SHELXS-2014 and SHELXL-2014 programs.

[0066] 2. Experimental Results

[0067] The single crystal structure analysis shows that the dysprosium-based complex prepared in Example 1 (referred to as Complex 1 in Table 1) belongs to the triclinic system, the space group is P-1, and the unit cell parameters are: α=69.733(2)°, β=88.444(2)°, γ=80.520(2)°, The crystallographic data are shown in Table 1.

[0068] Table 1 Crystallographic data and refinement results of magnetic / fluorescent bifunctional dysprosium complexes

[0069]

[0070]

[0071] Note: Weighting scheme expression: a R1=∑||F o |-|F c || / ∑|F o |, b wR2=[∑w(F o 2 -F c 2 ) 2 / ∑w(F o 2 ) 2 ] 1 / 2 .

[0072] Depend on Figure 2 From (a) to (d) in the figure, it can be seen that the asymmetric unit of the magnetic / fluorescent bifunctional dysprosium complex prepared in Example 1 includes a Dy III , a bbpen 2- Schiff base chelating ligand and a BPh4 -The counter anion and one half and one complete phosphine bridge ligand are surrounded by 4 crystallization solvents, acetonitrile. The central metal ion, dysprosium, forms an eight-coordinate bond with 4 nitrogen and 4 oxygen atoms. Due to the elementary assembly strategy, the 4 nitrogen and 2 oxygen atoms come from the same bbpen. 2- ligand, and the remaining two oxygens come from two different phosphine ligands, {Dy(bbpen)} + The motif is connected to the phosphine ligand by cis coordination to form a dinuclear structure. The intermolecular Dy-Dy distance is The shortest Dy-Dy distance within a molecule is The central Dy(III) ion has a tetragonal anti-prismatic geometry (D 4d ), the coordination geometry of the metal ions was confirmed using Shape software (Table 2). The average Dy-O and Dy-N bond lengths are and The shortest Dy-O bond length is From the Schiff base ligand bbpen 2- of phenolic oxygen.

[0073] Table 2 CShM values ​​of Dy(III) ions at the center of dysprosium complexes

[0074]

[0075]

[0076] From the infrared spectrum ( Figure 3 ) can be seen that at 1620cm -1 A clear carbonyl peak can be observed at 900-650cm -1 The out-of-plane deformation vibration of the CH on the aromatic ring appeared in the region. Compared with the phosphine oxide ligand, the absorption peaks of some functional groups of the complex have undergone red shifts and the intensity has also changed to a certain extent, all of which indicate that the fluorescent active organic ligand 1,4-butanediylbis(diphenylphosphine oxide) participates in the coordination.

[0077] Comparative Example 1

[0078] 1. Experimental Methods

[0079] The dysprosium-based complex was synthesized by referring to the method of Example 1, except that the reaction temperature was adjusted to 70°C or below.

[0080] 2. Experimental Results

[0081] The product is a powdery solid, and the complex crystals are not precipitated.

[0082] Comparative Example 2

[0083] 1. Experimental Methods

[0084] The dysprosium-based complex was synthesized by referring to the method of Example 1, except that the reaction time was set to be less than 72 h.

[0085] 2. Experimental Results

[0086] The product is a powdery solid precipitate or very small crystals, and its structure cannot be determined.

[0087] Comparative Example 3

[0088] 1. Experimental Methods

[0089] The dysprosium complex was synthesized by the method of Example 1, except that NaBPh4 was not added.

[0090] 2. Experimental Results

[0091] The product is a powdery solid, and the complex crystals are not precipitated.

[0092] Comparative Example 4

[0093] 1. Experimental Methods

[0094] The dysprosium complex was synthesized by referring to the method of Example 1, except that dichloromethane was replaced by ethanol or methanol.

[0095] 2. Experimental Results

[0096] The product is a powdery solid precipitate or microcrystals and cannot be structurally determined.

[0097] Comparative Example 5

[0098] 1. Experimental Methods

[0099] The dysprosium complex was synthesized by referring to the method of Example 1, except that no dichloromethane was added.

[0100] 2. Experimental Results

[0101] The product is a powdery solid precipitate or microcrystals and cannot be structurally determined.

[0102] Comparative Example 6

[0103] 1. Experimental Methods

[0104] The dysprosium complex was synthesized by referring to the method of Example 1, except that the precursor [Dy III (bbpen)NO3] is replaced by [Dy III (bbpen)Cl].

[0105] 2. Experimental Results

[0106] The product is a cluster of multi-nuclear microcrystals, which cannot be structurally determined.

[0107] It can be seen from Example 1 and Comparative Examples 1 to 6 that the preparation of the dysprosium-based complex of the present invention requires [Dy III (bbpen)NO3] is used as a precursor to carry out a solvothermal reaction at a reaction temperature of 75°C in a mixed solvent of acetonitrile and dichloromethane for 72 hours. At the same time, NaBPh4 needs to be added to provide a counter ion to balance the charge of the product, forming an external environment that is conducive to the reaction between the high-performance single-ion magnet unit and the phosphine oxide ligand, and is also conducive to the crystallization of the final complex product with a suitable solubility, thereby obtaining a functional complex with excellent appearance and high purity.

[0108] Example 3 DC susceptibility test

[0109] 1. Experimental Methods

[0110] Under an external DC magnetic field of 1000 Oe, a variable temperature DC magnetic susceptibility test was performed on the polycrystalline powder sample of the dysprosium-based complex prepared in Example 1 within a temperature range of 2 to 300 K.

[0111] 2. Experimental Results

[0112] The results are as follows Figure 4 The molar magnetic susceptibility χ of the dysprosium-based complex prepared in Example 1 at 300K is M The T test value is 14.13cm 3 K mol -1 , which is comparable to the theoretical value of a single free Dy(III) ion (14.17 cm 3 K mol -1 , 6 H 15 / 2 ,g J =4 / 3) is very close. As the temperature gradually decreases, χ M The T value shows a trend of gradually decreasing, and the lower the temperature, the faster the rate of decrease. This phenomenon is mainly caused by the decrease in temperature, which makes the number of electrons in the excited state of rare earth dysprosium ions decrease. This phenomenon is common in paramagnetic rare earth ions, indicating that the prepared dysprosium-based complex has obvious zero-field splitting.

[0113] Example 4 Magnetization Intensity Test

[0114] 1. Experimental Methods

[0115] The magnetization intensity of the powder sample of the dysprosium-based complex prepared in Example 1 was tested at temperatures of 5K, 10K, and 15K and a magnetic field range of 0 to 7T.

[0116] 2. Experimental Results

[0117] The results are as follows Figure 5As shown in the figure, the magnetization intensity of the dysprosium-based complex increases significantly with the increase of the external magnetic field. When it increases to a certain extent, the growth rate slows down and gradually tends to saturation. When the temperature is 5K and the external magnetic field is 7T, the maximum value is 5.32Nμ. B , which is consistent with the maximum M of a strongly anisotropic ground state Dy(III) in the powder sample. J = ±15 / 2 state in the high field limit saturation magnetization theoretical value 5Nμ B near( Figure 5 (a) in the figure shows that the dysprosium-based complex prepared in Example 1 has obvious zero-field splitting and significant magnetic anisotropy.

[0118] The reduced temperature-dependent magnetization intensity curves (MH / T) of the complexes basically overlap, indicating that there is a large anisotropy and obvious zero-field splitting in the dysprosium-based complexes. As the magnetic field increases, more electrons are more likely to be distributed in the microscopic electronic energy states of the ground state and the low excited state, rather than being evenly distributed in all MH. J state( Figure 5 This is consistent with the temperature-dependent DC magnetic susceptibility curve results of Example 3, and also indicates that the dysprosium-based complex has an approximate Ising ground state and exhibits single-molecule magnetic properties.

[0119] Example 5 Slow magnetic relaxation behavior

[0120] 1. Experimental Methods

[0121] In order to further analyze the slow magnetic relaxation behavior of the dysprosium-based complex prepared in Example 1, characterization tests of variable temperature and variable frequency AC magnetic susceptibility were carried out under zero external magnetic field and 1000 Oe.

[0122] 2. Experimental Results

[0123] like Figure 6 As shown in the figure, the dynamic magnetic behavior of the dysprosium-based complex shows the typical frequency-dependent slow magnetic relaxation phenomenon of single-molecule magnets, and has obvious single-molecule magnet characteristics. Specifically, due to the obvious magnetic quantum tunneling under zero external field, the imaginary signal of the variable temperature AC magnetic susceptibility curve does not show an obvious peak at low frequency, while the peak of the imaginary AC magnetic susceptibility at the highest frequency is 45K. After applying an external magnetic field, the magnetic quantum tunneling process is effectively suppressed: the "tail-up" phenomenon disappears at the lowest frequency and a peak appears.

[0124] like Figure 7 As shown in Figure 2, the generalized Debye model is used to fit the variable frequency AC magnetic susceptibility test curve to obtain the relaxation time τ at different temperatures. In the high temperature region, it can be found that the logarithm of the relaxation time ln(τ) increases with the inverse of the temperature K. -1 It changes linearly, that is, this relaxation is an Orbach process following the Arrhenius formula τ=τ0exp(U eff / k B T). However, as the temperature decreases, the relaxation time under zero external field gradually deviates from the Arrhenius formula with the change of temperature, and the relaxation time shows a nonlinear increase trend, indicating the existence of Raman process. Finally, it tends to be flat due to the limitation of magnetic quantum tunneling effect in the system. The relaxation process in the whole temperature range can be fitted by multiple relaxation involving three processes: Aubach, Raman and magnetic quantum tunneling to obtain the following parameters: Under zero field, τ0 = 1.42 × 10 -10 s, C0=0.0012s -1 K -n , n = 3.83, τ QTM =0.062s, effective energy barrier U eff / k B =663(61)K.

[0125] Example 6 Fluorescence Spectrum Test

[0126] 1. Experimental Methods

[0127] The solid powder sample of the dysprosium complex prepared in Example 1 was tested for fluorescence spectrum at 25°C and low temperature using an Edinburgh FLS-980 steady-state / transient fluorescence spectrometer, with a xenon lamp as the light source and a photomultiplier tube (PMT) as the detector. The emission wavelength was 483.8 nm and the excitation wavelength was 312 nm.

[0128] 2. Experimental Results

[0129] Due to the successful introduction of the phosphine oxide ligand with an aromatic group, the luminescence efficiency of the rare earth ion was improved through sensitization, so three groups of Dy peaks with sharp peaks and high resolution were observed in the prepared dysprosium complex at 25°C and low temperature. III The characteristic fluorescence peak of Fig. 9 ), from which valuable energy level information was obtained, and the fluorescence lifetime was 13.272μs ( Fig.10 ). At 25°C, the spectrum peaks are broadened and mixed, and multiple peaks are difficult to distinguish. When the temperature is lowered, the peaks of the emission spectrum become sharp and clear. Figure 8 The emission spectrum shows that Dy III The three characteristic peaks are at 468nm (21358cm -1 , 4 F 9 / 2 → 6 H 15 / 2 ), 575nm(17400cm -1 , 4 F 9 / 2 → 6 H 13 / 2 ) and 670nm(15000cm -1 ,4 F 9 / 2 → 6 H 11 / 2 ), corresponding to the ff transition of rare earth ions.

[0130] Example 7 X-ray powder diffraction

[0131] 1. Experimental Methods

[0132] In order to detect the stability of the dysprosium-based complex prepared in Example 1, an X-ray powder diffraction test was performed after it was placed in air for two weeks.

[0133] 2. Experimental Results

[0134] The results are as follows Fig.11 As shown, the peak position, peak shape and peak intensity of the simulated peak and the test peak are basically consistent, indicating that the complex is relatively stable and can be stored in an air environment for a long time.

[0135] In general, based on the above test results, it can be seen that the dysprosium-based complex prepared in Example 1 is a zero-dimensional binary core structure, has excellent slow magnetic relaxation properties of a single-molecule magnet, and exhibits a fine linear fluorescence spectrum characteristic of dysprosium ions, has a magnetic and fluorescent dual function, and can be used as a magnetic / optical functional material. In terms of the preparation method, the dysprosium-based complex of the present invention has a rich selection of raw materials for preparation, is simple and easy to operate, and can achieve high yield and high crystallinity sample preparation through low-temperature solvent heat and room temperature volatilization reaction, which meets the development needs of green chemistry. The bifunctional dysprosium-based complex has a high application value in molecular-based magnetic materials and sharp-line light source fluorescent materials.

[0136] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A dysprosium-based complex having magnetic and fluorescent dual functions, characterized in that: The structural formula of the dysprosium complex is [Dy(bbpen)(dppBO2)2](BPh4)·4MeCN, wherein (bbpen) 2- is the anion of N, N'-bis(2-hydroxybenzyl)-N, N'-bis(2-pyridylmethyl)ethylenediamine, dppBO2 is 1,4-butanediylbis(diphenylphosphine oxide), (BPh4) - is the tetraphenylborate ion; The dysprosium-based complex crystallizes in the triclinic system, belongs to the P-1 space group, and the unit cell parameters are: α=69.733(2)°, β=88.444(2)°, γ=80.520(2)°, 2. The method for preparing the dysprosium-based complex according to claim 1, characterized in that: The following steps are involved: S1. III (bbpen)NO3], acetonitrile and dichloromethane were fully mixed, and then dppBO2 was added. After mixing well, NaBPh4 was added and mixed again to obtain a mixed solution; Said III The structural formula of (bbpen)NO3] is shown in formula (I): The structural formula of the dppBO2 is shown in formula (II): Where n = 4; S2. The mixed solution is reacted at a constant temperature of 74 to 76°C for 72 to 73 hours, then cooled to 24 to 26°C, the solid-liquid separation is performed to obtain the liquid, and the liquid is allowed to stand at 24 to 26°C for crystallization to obtain the dysprosium-based complex.

3. The preparation method according to claim 2, characterized in that: In step S1, the [Dy III The usage ratio of (bbpen)NO3], acetonitrile, dichloromethane, dppBO2 and NaBPh4 is (1~1.4) mg: (1~1.4) mL: (0.6~1.0) mL: 1 mg: (0.4~0.8) mg.

4. The preparation method according to claim 3, characterized in that: Said III The usage ratio of (bbpen)NO3], acetonitrile, dichloromethane, dppBO2 and NaBPh4 is 1.2mg:1.2mL:0.8mL:1mg:0.6mg.

5. The preparation method according to claim 2, characterized in that: In step S2, the temperature is 75°C.

6. The preparation method according to claim 2, characterized in that: In step S2, the isothermal reaction time is 72 hours.

7. The preparation method according to claim 2, characterized in that: In step S2, the cooling rate is 4-6°C / h.

8. Use of the dysprosium-based complex according to claim 1 in the preparation of magnetic materials and / or fluorescent materials.

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