A high quantum yield rare earth terbium cluster compound with thiacalixarene as ligand, preparation method and application thereof

Abstract

The present invention provides a high quantum yield rare earth terbium cluster compound with thiacalixarene as a ligand, a preparation method and an application thereof. The chemical formula of the rare earth terbium cluster compound is: [(CH3)2NH2][Tb9(TC4A)2(μ3-O)8(μ4-O)2(H2O) 24 The rare earth terbium cluster compound is constructed with H4TC4A as a ligand and Tb(CH3COO)3·6H2O as a metal source. The rare earth terbium cluster compound provided by the present invention has good photoluminescence properties, good solubility in methanol and high fluorescence quantum yield, and can be widely used in technical fields such as light detection.

Description

Technical Field

[0001] The invention relates to the technical field of rare earth metals, and in particular to a high quantum yield rare earth terbium cluster compound using thiacalixarene as a ligand, a preparation method and an application thereof. Background Art

[0002] Rare earth metals are often used to prepare high-performance luminescent complexes. Compared with transition metals, luminescent rare earth complexes have the following advantages: (1) rich and diverse emission spectra; (2) ff transitions present sharp linear spectra and high color purity of luminescence; (3) fluorescence lifetimes span six orders of magnitude from nanoseconds to milliseconds; (4) strong ability to absorb excitation energy and high conversion rate; (5) stable physical and chemical properties, and can withstand high-power electron beams, high-energy radiation, and strong ultraviolet light.

[0003] The electron transfer of lanthanide ions is often constrained by the Laporte rule, and its 4f-4f transition is forbidden. Therefore, lanthanide ions are not easy to produce good emission light when directly excited by light. In order to overcome the problem of low luminescence efficiency caused by the Laporte rule, the most common and effective method is to find an organic ligand to combine with it. After the organic ligand absorbs the energy of the radiation light, it transfers the energy to the rare earth ion, thereby enhancing the luminescence of the rare earth ion.

[0004] After common organic ligands form complexes with rare earth metals, the radiation and non-radiation processes are not ideal, and the fluorescence quantum yield is low. In order to solve this problem, researchers have tried to find suitable ligands to synthesize chelates, reducing the contact between the central rare earth ions and external substances to reduce energy loss, so as to achieve the purpose of enhancing the fluorescence quantum yield; on the other hand, by adding a second metal or an auxiliary ligand, under certain reaction conditions, the raw materials are added in a certain proportion to synthesize rare earth complexes with a specific structure, and the coordination environment of the rare earth ions is changed by coordination configuration, electronic regulation, or the combined action of the two to improve its fluorescence quantum yield. However, when different ligands are used to enhance the luminescence intensity of rare earth ions, some of the synthesis processes are complicated and the fluorescence quantum yield is low. Summary of the invention

[0005] The present invention provides a high quantum yield rare earth terbium cluster compound with thiacalixarene as a ligand, a preparation method and an application thereof, so as to solve the problem of low fluorescence quantum yield when different ligands enhance the luminescence intensity of rare earth ions.

[0006] The invention provides a high quantum yield rare earth terbium cluster compound with thiacalixarene as a ligand, the chemical formula of the rare earth terbium cluster compound is: [(CH3)2NH2][Tb9(TC4A)2(μ3-O)8(μ4-O)2(H2O) 24For ease of description, the rare earth terbium cluster compound in this application is abbreviated as Tb9. The Tb9 belongs to the tetragonal system, the space group is P-4, and the unit cell parameters are α=90°, β=90°, γ=90°,

[0007] At an excitation wavelength of 320 nm, the concentration was 2×10 -5 The fluorescence quantum yield of the methanol solution of Tb9 at mol / L is 59.19%. At an excitation wavelength of 340 nm, the concentration is 2×10 -5 The fluorescence quantum yield of mol / L Tb9 methanol solution is 59.65%.

[0008] The present application also provides a method for preparing a high quantum yield rare earth terbium cluster compound with thiacalixarene as a ligand, wherein H4TC4A (Chinese name: tert-butylthiacalix[4]arene) is used as a ligand and Tb(CH3COO)3·6H2O is used as a metal source to construct Tb9. The specific preparation method includes:

[0009] S01: H4TC4A and Tb(CH3COO)3·6H2O were dissolved in a mixed solvent, and the temperature was raised to 130°C at a heating rate of 1°C / min, and the temperature was maintained at a constant temperature for three days.

[0010] H4TC4A and Tb(CH3COO)3·6H2O were dissolved in a mixed solvent at a molar ratio of 1:5, and the mixed solvent included CH3OH, DMF (English name: N,N-Dimethylformamide, Chinese name: N,N-dimethylformamide) and H2O, and the volume ratio was 3:7:1. Adding a small amount of water to the mixed solvent is conducive to the crystallization of Tb9. After being placed in a polytetrafluoroethylene liner, the temperature was raised to 130°C at a heating rate of 1°C / min and kept at a constant temperature for three days.

[0011] S02: After the constant temperature is completed, the temperature is lowered to room temperature at a cooling rate of 4°C / min to obtain a suspension;

[0012] S03: filtering the suspension to obtain a colorless transparent solution, and volatilizing the colorless transparent solution at 25° C. to obtain a blocky crystalline rare earth terbium cluster compound.

[0013] The key to the preparation of Tb9 lies in the ratio of the reaction raw materials and the type and proportion of the mixed solvent. After a large number of experiments, it was found that only when the molar ratio of H4TC4A and Tb(CH3COO)3·6H2O is 1:5 and the volume ratio of CH3OH, DMF and H2O is 3:7:1, can the pure Tb9 with a yield of 60% be synthesized. Figure 1 Rare earth terbium cluster compound with the crystal structure shown.

[0014] The Tb9 provided in the present application has good photoluminescence properties, good solubility in methanol and high fluorescence quantum yield, and can be used in the field of light detection.

[0015] The technical solution provided by the embodiments of the present invention may have the following beneficial effects:

[0016] The present invention provides a high quantum yield rare earth terbium cluster compound with thiacalixarene as a ligand, a preparation method and an application thereof. The chemical formula of the rare earth terbium cluster compound is: [(CH3)2NH2][Tb9(TC4A)2(μ3-O)8(μ4-O)2(H2O) 24 The rare earth terbium cluster compound is constructed with H4TC4A as a ligand and Tb(CH3COO)3·6H2O as a metal source. The rare earth terbium cluster compound provided by the present invention has good photoluminescence properties, good solubility in methanol and high fluorescence quantum yield, and can be widely used in technical fields such as light detection.

[0017] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the embodiments are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Figure 1 A crystal structure diagram of Tb9 provided in an embodiment of the present invention;

[0020] Figure 2 The PXRD (full name in English: powder diffraction of x-rays; Chinese name: powder X-ray diffraction) diagram of Tb9 provided in the embodiment of the present invention;

[0021] Figure 3 FTIR (Full name in English: Fourier Transform infrared spectroscopy; Chinese name: Fourier transform infrared spectroscopy) graph of Tb9 provided in the embodiment of the present invention;

[0022] Figure 4 A thermogravimetric graph of Tb9 provided in an embodiment of the present invention;

[0023] Figure 5 This is a solid-state fluorescence spectrum diagram of Tb9 provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The present application provides a high quantum yield rare earth terbium cluster compound with thiacalixarene as a ligand, the rare earth terbium cluster compound is referred to as Tb9. The chemical formula of Tb9 is: [(CH3)2NH2][Tb9(TC4A)2(μ3-O)8(μ4-O)2(H2O) 24 ]. The Tb9 is constructed with H4TC4A as ligand and Tb(CH3COO)3·6H2O as metal source. It belongs to the tetragonal system, the space group is P-4, and the unit cell parameters are α=90°, β=90°, γ=90°,

[0025] The Tb9 was subjected to X-ray single crystal diffraction detection on a Bruker D8 QUEST diffractometer, wherein a graphite monochromator was used, Mo-Kα (λ=0.071073 nm) was used as the light source, and the data was restored using the Saint software package to obtain the attached Figure 2 The XRD pattern is shown in Figure 2. In addition, the structure was analyzed using the SHELXL-2014 program, and the full-matrix least-squares refinement based on F 2 ) to perform structural refinement, and obtain the crystallographic data and structural refinement parameters shown in Table 1 and the attached Figure 1 The crystal structure diagram is shown.

[0026] Table 1: Crystallographic data and structure refinement parameters of Tb9

[0027]

[0028] a R1=Σ||F0|-|F c || / Σ|F0|; b wR2={Σ[w(F0 2 -F c 2 ) 2 ] / Σ[w(F0 2 ) 2 ]} 1 / 2 .

[0029] From Table 1, Appendix Figure 1 and 2 It can be seen that the molecular structure of Tb9 contains two tert-butylthiacalix[4]arene ligands and nine rare earth terbium ion centers, forming a structure in which two "tail-to-tail" calixarene ligands sandwich nine metal terbium. Tb9 loses its crystallinity under ambient conditions.

[0030] The following is a description of the preparation method of Tb9 provided in the present application in the form of a specific embodiment, but the specific numerical values ​​in the method do not limit the protection scope of the present application.

[0031] The preparation method of Tb9 provided in the present application comprises:

[0032] S01: Weigh 80 mg of H4TC4A and 200 mg of Tb(CH3COO)3·6H2O, and place the weighed H4TC4A and Tb(CH3COO)3·6H2O in a 20 mL polytetrafluoroethylene liner. Add 3 mL of CH3OH, 7 mL of DMF, and 1 mL of H2O to the polytetrafluoroethylene liner, mix them evenly, and then seal them in a stainless steel reactor. In a forced air oven, heat the mixture to 130°C at a heating rate of 1°C / min and keep the temperature constant for three days.

[0033] S02: After the constant temperature is completed, the temperature is slowly lowered to room temperature at a cooling rate of 4°C / min to obtain a suspension.

[0034] S03: The suspension is filtered through filter paper to obtain a colorless transparent solution, and the colorless transparent solution is placed at room temperature of 25° C. to slowly evaporate to obtain a blocky crystalline rare earth terbium cluster compound, namely Tb9. The yield of Tb9 is 60%.

[0035] In the present application, except for tert-butylthiacalix[4]arene which is self-made, the other reagents are purchased from commercial channels without any treatment. The preparation method of tert-butylthiacalix[4]arene in the present application includes:

[0036] S11: NaOH and tetraethylene glycol dimethyl ether were heated in a nitrogen atmosphere at 150°C oil bath for 1 h to obtain reaction product a;

[0037] S12: adding p-tert-butylphenol and sublimed sulfur to the reaction product a cooled to room temperature, raising the temperature from 25° C. to 238° C. over 4 hours, and reacting at the constant temperature for 4 hours to obtain a reaction product b;

[0038] S13: Add ether and toluene to the reaction product b cooled to room temperature, stir at room temperature until all large lumps are dispersed into small particles, then add dilute sulfuric acid, and continue stirring until no lumps exist to obtain a reaction product c; wherein the concentration of the dilute sulfuric acid is 4 mol / L.

[0039] S14: The reaction product c is filtered, washed with ethanol, dried, and recrystallized from CHCl3 to obtain tert-butylthiacalix[4]arene.

[0040] The present invention also characterizes Tb9 by Fourier infrared spectroscopy, thermogravimetric curve and solid-state fluorescence, and obtains the attached Figure 3-5 Attached Figure 3The FTIR graph shown in the figure shows that 2965cm -1 The peak at 1584 cm is attributed to the CH bond in the p-tert-butyl group of the calixarene. -1 and 1455cm -1 The peak of Ln-OC is located at 1308 cm -1 and 1251cm -1 Attached Figure 4 The thermogravimetric curve shown in the figure shows that the crystal framework of Tb9 can be maintained up to 460°C, after which the framework begins to decompose. Figure 5 The solid-state fluorescence spectrum shown in the figure shows that at room temperature, the excitation wavelength of Tb9 is 350nm. At the excitation wavelength of 350nm, the four typical characteristic emission peaks of the corresponding rare earth terbium are 492nm, 547nm, 586nm and 621nm. This shows that Tb9 has good photoluminescence properties.

[0041] Furthermore, the present application also tested the fluorescence quantum yield of different concentrations of Tb9 dissolved in methanol at room temperature. The fluorescence quantum yield is shown in Table 2.

[0042] Table 2: Fluorescence quantum yield of methanol solutions of Tb9 at different concentrations

[0043] <![CDATA[2×10 -5 mol / L]]> <![CDATA[8×10 -6 mol / L]]> <![CDATA[6×10 -6 mol / L]]> <![CDATA[4×10 -6 mol / L]]> <![CDATA[2×10 -6 mol / L]]> 320nm 59.19％ 59.19％ 58.98％ 54.40％ 54.40％ 340nm 59.65％ 59.48％ 55.12％ 54.86％ 55.50％

[0044] As can be seen from Table 2, at room temperature, under an excitation wavelength of 320 nm, the concentration is 2×10 -5 The fluorescence quantum yield of the methanol solution of Tb9 at mol / L is 59.19%; at an excitation wavelength of 340 nm, the concentration is 2×10 -5 The fluorescence quantum yield of the mol / L Tb9 methanol solution is 59.65%, which shows that Tb9 has good solubility and high fluorescence quantum yield in methanol and can be widely used in technical fields such as light detection.

[0045] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the disclosure of the invention herein. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0046] It should be understood that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A high quantum yield rare earth terbium cluster compound with thiacalixarene as ligand, characterized in that: The chemical formula of the rare earth terbium cluster compound is: [(CH3)2NH2][Tb9(TC4A)2(μ3-O)8(μ4-O)2(H2O) 24 ], the rare earth terbium cluster compound belongs to the tetragonal system, the space group is P-4, and the unit cell parameters are α=90°, β=90°, γ=90°, 2. The high quantum yield rare earth terbium cluster compound with thiacalixarene as ligand according to claim 1, characterized in that: At an excitation wavelength of 320 nm, the concentration was 2×10 -5 The fluorescence quantum yield of the mol / L methanol solution of the rare earth terbium cluster compound is 59.19%.

3. The high quantum yield rare earth terbium cluster compound with thiacalixarene as ligand according to claim 1, characterized in that: At an excitation wavelength of 340 nm, the concentration was 2×10 -5 The fluorescence quantum yield of the mol / L methanol solution of the rare earth terbium cluster compound is 59.65%.

4. The method for preparing a high quantum yield rare earth terbium cluster compound with thiacalixarene as a ligand according to any one of claims 1 to 3, characterized in that: The method comprises: H4TC4A and Tb(CH3COO)3·6H2O were dissolved in a mixed solvent, heated to 130°C at a heating rate of 1°C / min, and kept at a constant temperature for three days; After the constant temperature is completed, the temperature is lowered to room temperature at a cooling rate of 4°C / min to obtain a suspension; Filtering the suspension to obtain a colorless transparent solution, and volatilizing the colorless transparent solution to obtain a blocky crystalline rare earth terbium cluster compound; The molar ratio of the H4TC4A to the Tb(CH3COO)3·6H2O is 1:5; The mixed solvent is selected from CH3OH, DMF and H2O; The volume ratio of the CH3OH, the DMF and the H2O is 3:7:

1.

5. The method for preparing a high quantum yield rare earth terbium cluster compound with thiacalixarene as a ligand according to claim 4, characterized in that: The evaporation temperature of the colorless transparent solution is 25°C.

6. Use of the high quantum yield rare earth terbium cluster compound with thiacalixarene as ligand according to any one of claims 1 to 3 in light detection.

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