A two-dimensional dysprosium complex with magnetic and fluorescent properties, and a preparation method and application thereof

Abstract

The application discloses a two-dimensional dysprosium complex with magnetic and fluorescent properties, a preparation method and application thereof, relates to the technical field of multifunctional dysprosium complexes, and aims to provide a two-dimensional dysprosium complex with good controllability, simple preparation and magnetic and fluorescent properties.The technical scheme points are as follows: the chemical formula of the dysprosium complex is [Dy2(INO)4(NO3)2] n The complex Dy(III) ions are all nine-coordinated single cap tetragonal antiprism configuration; the complex in the application presents typical single-molecule magnet behavior, and can be used as a molecular-based magnetic material in high-density information storage equipment.The complex in the application belongs to a luminescent material, and can emit strong blue fluorescence under ultraviolet lamp irradiation.The sensitization of the HINO ligand can provide energy for dysprosium ions to be excited, so that the complex exhibits dysprosium ion characteristic linear fluorescent spectrum.The complex can be synthesized through a simple solvothermal method, and has simple preparation process and easy operation, and is easy to obtain a pure phase.

Description

Technical Field

[0001] This invention relates to the field of multifunctional dysprosium complex technology, specifically to a two-dimensional dysprosium complex with magnetic and fluorescent properties, its preparation method, and its application. Background Technology

[0002] Existing rare earth complex emitters suffer from several prominent problems, including insufficient stability, poor solubility, susceptibility to aggregation-induced quenching (ACQ) in aqueous solutions, and unclear luminescence mechanisms. These issues limit the application of rare earth complex emitters.

[0003] Chinese patent CN102993222B discloses a dysprosium coordination polymer material with solvent molecular magnetic response and its preparation method. It uses HINO (isonicotinic acid-N-oxide) ligand to obtain a binuclear dysprosium complex with a three-dimensional porous structure. Although the complex exhibits slow magnetic relaxation behavior and its preparation method is simplified compared to traditional methods, there are two μ2 oxygen atoms and two carboxyl oxygen atoms between the binucleates. During the synthesis process, they are bridged into a three-dimensional structure by ligands. Moreover, its magnetic regulation depends on multiple post-processing steps such as acetonitrile solvent exchange and high-temperature activation at 200℃. The synthesis process still has room for simplification and improvement. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the existing defects and provide a two-dimensional dysprosium complex with magnetic and fluorescent properties, its preparation method and application, which can effectively solve the problems in the background art.

[0005] To achieve the above objectives, this invention first discloses a two-dimensional dysprosium complex with magnetic and fluorescent properties. The technical solution adopted is that the chemical formula of the complex is [Dy(INO)4(NO3)2]. n INO - The isonicotinic acid-N-oxide anion is formed by removing one carboxyl motonic atom, where n represents the degree of polymerization and is a positive integer; the complete coordination structure of the central metal Dy(III) ion is shown below:

[0006] ;

[0007] It contains multiple HINO ligands, the structural formulas of which are as follows:

[0008] ;

[0009] The complex is composed of binuclear {Dy2} molecules. By adding triethylamine during synthesis, Dy1 and Dy1A are connected by the carboxyl oxygen atom of ligand HINO (isonicotinic acid-N-oxide). The molecules are extended into a two-dimensional network structure through the extension of coordination on both sides of ligand HINO. The complex exhibits single-molecule magnetic behavior and a line emission fluorescence spectrum characteristic of dysprosium ions.

[0010] As a preferred embodiment of the two-dimensional dysprosium complex of the present invention, the complex belongs to the monoclinic crystal system with space group P21 / c; the cell parameters are a = 10.1122 (3) Å, b = 17.4075 (6) Å, c = 11.4581 (3) Å, α = 90°, β = 109.660 (2)°, γ = 90°, Z = 2, ρ cal (g / cm 3 = 1.751 g / cm 3 μ = 21.49 mm -1 , F(000) = 956, R1 = 0.0412, wR2 = 0.1243 [I > 2σ(I)].

[0011] As a preferred embodiment of the two-dimensional dysprosium complex of the present invention, the complex includes Dy(III) ions and ligand INO. - Ions and NO 3- The Dy(III) ions are all nine-coordinated monocapted tetragonal antiprisms, wherein the nine coordinated oxygen atoms are: two from the N-oxide in the HINO ligand, five from the carboxyl group in the HINO ligand, and two from the NO3 in the metal salt Dy(NO)3·6H2O. - O atoms.

[0012] Furthermore, this invention discloses a method for preparing the above-mentioned two-dimensional dysprosium complex. The technical solution is as follows: HINO, Dy(NO)3·6H2O, EtOH and Et3N are added to a reaction vessel, stirred at room temperature for 5 minutes, and then placed in an oven at 120°C for 3 days to obtain colorless elongated crystals. After filtration and washing with ethanol, the dysprosium complex is obtained.

[0013] As a preferred technical solution of the preparation method of the present invention, the molar ratio of HINO, Dy(NO)3·6H2O and Et3N is 5:1:1.

[0014] The two-dimensional dysprosium complexes disclosed in this invention are used in the fields of biomedical imaging, chemical sensing, information storage, or optoelectronic functional materials.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: By adding triethylamine during synthesis, the binucleates of the complex are linked by the carboxyl oxygen atoms of the HINO ligand, thus providing a basis for two-dimensional extension; the structure of the obtained complex is stable and controllable, exhibiting a highly symmetrical spatial structure, and it exists stably in air. It also has outstanding single-molecule magnetic behavior and a linear emission fluorescence spectrum characteristic of dysprosium ions, which can be used as a multifunctional magnetic / optical material in special environments; the synthesis only requires one solvothermal synthesis to directly obtain high-purity crystalline products without subsequent processing, making the process more economical, simple, and controllable. Attached Figure Description

[0016] Figure 1 This is a diagram of the HINO ligand used in the magnetic / fluorescent two-dimensional dysprosium complex of this invention;

[0017] Figure 2 This is a schematic diagram of the crystal structure of the magnetic / fluorescent two-dimensional dysprosium complex of the present invention;

[0018] Figure 3 This is a polyhedral structure diagram of the magnetic / fluorescent two-dimensional dysprosium complex of the present invention;

[0019] Figure 4 This is a coordination mode diagram of the magnetic / fluorescent two-dimensional dysprosium complex of the present invention;

[0020] Figure 5 This is a two-dimensional diagram of the magnetic / fluorescent two-dimensional dysprosium complex of the present invention;

[0021] Figure 6 This is a temperature-dependent magnetic susceptibility diagram of the magnetic / fluorescent two-dimensional dysprosium complex of the present invention;

[0022] Figure 7 This is a magnetization curve of the magnetic / fluorescent two-dimensional dysprosium complex of the present invention;

[0023] Figure 8 This is a diagram showing the imaginary part of the temperature-dependent AC magnetic susceptibility of the magnetic / fluorescent two-dimensional dysprosium complex of the present invention.

[0024] Figure 9 This is a swept-frequency AC magnetic susceptibility diagram of the magnetic / fluorescent two-dimensional dysprosium complex of the present invention.

[0025] Figure 10 This is the fluorescence emission spectrum of the magnetic / fluorescent two-dimensional dysprosium complex of the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1

[0028] This invention discloses a method for preparing two-dimensional dysprosium complexes with magnetic and fluorescent properties. The technical solution includes the following steps:

[0029] HINO (0.25 mmol) and Dy(NO)3·6H2O (0.05 mmol) were weighed into a reaction vessel, and 8 mL of EtOH and 1 d of Et3N (0.05 mmol) were added. The mixture was stirred at room temperature for 5 min, then placed in an oven and reacted at 120 °C for 3 days to obtain colorless elongated crystals. After filtration and washing with ethanol, the magnetic / fluorescent two-dimensional dysprosium complex was obtained. The complete coordination structure of the central metal Dy(III) is as follows:

[0030] ,

[0031] The chemical formula of this complex is [Dy2(INO)4(NO3)2]. n Its ligand structure is as follows Figure 1 As shown, INO - The isonicotinic acid-N-oxide anion is formed by removing one carboxyl motif, where n represents the degree of polymerization and is a positive integer. The unit cell parameters of the complex are: a = 10.1122 (3) Å, b = 17.4075 (6) Å, c = 11.4581 (3) Å, α = 90°, β = 109.660 (2)°, γ = 90°, Z = 2, ρ cal (g / cm 3 = 1.751 g / cm 3 μ = 21.49 mm -1 F(000) = 956, R1 = 0.0412, wR2 = 0.1243 [I > 2σ(I)]; detailed crystallographic data are shown in Table 1:

[0032] Table 1 Crystallographic data of the magnets

[0033]

[0034] Depend on Figure 2It can be seen that the binuclear {Dy2} structure of the complex consists of the following: two Dy(III) ligands and four INO ligands. - and two NO3 - Composition. Both Dy(III) ions are nine-coordinated monocapted tetragonal antiprisms. Figure 3 As shown), of the 9 coordinated oxygen atoms, 2 come from the ligand INO. - The oxygen atoms (O8A″, O9A′) in the N-oxide come from the ligand INO. - The oxygen atoms on the carboxyl group (O1, O2, O2A, O6A, O7A), and the remaining two O atoms come from NO3 in the metal salt Dy(NO)3·6H2O. - The O atoms (O3, O4). The central Dy(III) ion exhibits two different coordination modes, namely μ3-η. 1 :η 1 :η 1 and μ3-η 1 :η 2 :η 1 ( Figure 4 As shown). The complex is composed of two nuclei, with Dy1 and Dy1A linked together by the carboxyl oxygen atom bridge of ligand HINO, while the molecules are extended into a two-dimensional network structure through the extension of coordination on both sides of ligand HINO. Figure 5 (As shown).

[0035] The magnetic and optical properties of the obtained two-dimensional dysprosium complex were tested:

[0036] Figure 6 This is a temperature-varying magnetic susceptibility diagram of a two-dimensional dysprosium complex (magnet) under an applied DC field of 1000 Oe, within the temperature range of 300-2 K. Its magnetic susceptibility at 300 K is shown below. Value Below two spin-only Dy(III) ions ( 6 H 15 / 2 The theoretical values ​​of S = 5 / 2, L = 5, g = 4 / 3) As the temperature decreases, the magnet... The value then decreased.

[0037] Figure 7 The graph shows the magnetization of the magnet at different temperatures. With increasing external field, the magnetization at each temperature increases, eventually approaching saturation. Furthermore, the magnetization curves at different temperatures (2, 4, and 6 K) do not overlap. These results indicate that the Dy(III) ions within the magnet molecules exhibit anisotropic and / or low-level excited-state distribution.

[0038] Figure 8 and Figure 9 These are the imaginary parts of the alternating magnetic susceptibility of the magnet under zero DC external field conditions. The molecule exhibits frequency dependence in the temperature range of 2-4 K, indicating that it has typical single-molecule magnet behavior.

[0039] Figure 10 The image shows the fluorescence spectrum of this complex. The fluorescence spectra of the prepared two-dimensional dysprosium complex solid sample were measured at room temperature using an Edinburgh FS5 fluorescence spectrometer. Figure 10 As shown in (a), with a fixed emission wavelength of 574 nm, scanning the excitation spectrum between 320 and 500 nm revealed multiple excitation peaks, leading to the determination that 353 nm was the optimal excitation wavelength. Figure 10 As shown in (b), with a fixed excitation wavelength of 353 nm, the emission spectrum was scanned between 400 and 700 nm. Fluorescence emission peaks of the complex were observed at 488 nm, 578 nm, and 677 nm, which belong to the dysprosium ion, respectively. 4 F 9 / 2 → 6 H 15 / 2 , 4 F 9 / 2 → 6 H 13 / 2 and 4 F 9 / 2 → 6 H 11 / 2 Three energy level transitions produce emission spectra at specific frequencies. This characteristic spectrum is generated by the ligand absorbing energy, transitioning from the ground state to an excited singlet state, then transferring energy between systems to the triplet state, and finally transferring the energy to the dysprosium ion. The dysprosium ion's ground-state electrons are excited, transforming into an excited state, and then emitting fluorescence in the form of radiation, releasing the energy back to the ground state.

[0040] Based on the above test results, it can be seen that the two-dimensional dysprosium complex of Example 1 exhibits a highly symmetrical spatial structure, is stable in air, and has a prominent single-molecule magnetic behavior and a linear emission fluorescence spectrum characteristic of dysprosium ions. It can be used as a multifunctional magnetic / optical material in special environments.

[0041] The preparation method of this invention is simple, easy to implement, highly controllable, and produces high purity. This two-dimensional dysprosium complex can be used as a potential molecular-based magnetic material and a sharp-line fluorescent material for special working environments, demonstrating high application value.

[0042] Compared with Chinese patent CN102993222B (comparative example), Example 1 exhibits substantial differences in coordination chemistry, structural construction, synthetic strategy, and performance integration. By adding triethylamine during the preparation process, the proton on the carboxyl group is removed, achieving bridging between the binucleates via the carboxyl oxygen atom of the ligand HINO. In terms of preparation, Example 1 requires only one solvothermal synthesis (120°C, in the presence of triethylamine) to directly obtain a high-purity crystalline product, requiring no subsequent processing, making the process more economical and simpler. Regarding functional properties, the comparative example mainly focuses on the response regulation of solvent molecules to magnetic properties, without addressing fluorescence performance; while Example 1 simultaneously achieves single-molecule magnetic behavior and dysprosium ion-like linear fluorescence emission in the same complex, demonstrating the unique advantage of integrated magneto-optical dual functions. In summary, both examples represent fundamental differences and advancements in coordination mode, spatial dimension, synthetic route, and performance orientation.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A two-dimensional dysprosium complex with magnetic and fluorescent properties, characterized in that, The chemical formula of the complex is [Dy(INO)4(NO3)2]. n INO - The isonicotinic acid-N-oxide anion is formed by removing one carboxyl motonic atom, where n represents the degree of polymerization and is a positive integer; the complete coordination structure of the central metal Dy(III) ion is shown below: ； The complex is composed of binuclear {Dy2} molecules. By adding triethylamine during synthesis, Dy1 and Dy1A are connected by carboxyl oxygen atoms of ligand HINO, and the molecules are extended into a two-dimensional network structure through the extension of coordination on both sides of ligand HINO. The complex has a single-molecule magnetic behavior and a linear emission fluorescence spectrum characteristic of dysprosium ions.

2. The two-dimensional dysprosium complex with magnetic and fluorescent properties according to claim 1, characterized in that: The complex belongs to the monoclinic crystal system with space group P21 / c; the cell parameters are a = 10.1122 (3) Å, b = 17.4075 (6) Å, c = 11.4581 (3) Å, α = 90°, β = 109.660 (2)°, γ = 90°, Z = 2, ρ cal (g / cm 3 = 1.751g / cm 3 μ = 21.49 mm -1 , F(000) = 956, R1 = 0.0412, wR2 = 0.1243 [I > 2σ(I)].

3. The two-dimensional dysprosium complex with magnetic and fluorescent properties according to claim 1, characterized in that: The complex includes Dy(III) ions and ligand INO. - Ions and NO 3- The Dy(III) ions are all nine-coordinated monocapted tetragonal antiprisms, wherein the nine coordinated oxygen atoms are: two from the N-oxide in the HINO ligand, five from the carboxyl group in the HINO ligand, and two from the NO3 in the metal salt Dy(NO)3·6H2O. - The O atom in it.

4. A method for preparing a two-dimensional dysprosium complex with magnetic and fluorescent properties as described in claim 1, characterized in that: HINO, Dy(NO)3·6H2O, EtOH and Et3N were added to a reaction vessel and stirred at room temperature for 5 min. The mixture was then placed in an oven and reacted at 120℃ for 3 days to obtain colorless elongated crystals. After filtration and washing with ethanol, the dysprosium complex was obtained.

5. The method according to claim 4, characterized in that: The molar ratio of HINO, Dy(NO)3·6H2O and Et3N is 5:1:

1.

6. An application of a two-dimensional dysprosium complex with magnetic and fluorescent properties, characterized in that: The two-dimensional dysprosium complex with magnetic and fluorescent properties as described in claim 1 can be used in the fields of biomedical imaging, chemical sensing, information storage, or optoelectronic functional materials.

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