CN110229194B

CN110229194B - Antimony tungstate material with dysprosium ions and antimony ions bridged simultaneously, and preparation method and application thereof

Info

Publication number: CN110229194B
Application number: CN201910566535.8A
Authority: CN
Inventors: 陈利娟; 赵俊伟; 徐鑫; 张琰
Original assignee: Henan University
Current assignee: Henan University
Priority date: 2019-06-27
Filing date: 2019-06-27
Publication date: 2021-09-07
Anticipated expiration: 2039-06-27
Also published as: CN110229194A

Abstract

The invention relates toAn antimony tungstate material with dysprosium ions and antimony ions bridged simultaneously, which has the chemical formula: [ H ]₂N(CH₃)₂]₈Na₆H₈{[Dy₄(H₂O)₆Sb₆O₄](SbW₁₀O₃₇)₂(SbW₈O₃₁)₂}·24H₂O, belonging to the monoclinic system,P2(1)/nspace group, cell parameter ofa=13.0803(2)Å，b=40.6206(8)Å，c=19.3144(3)Å，α=90.00º，β=99.4600(10)º，γ=90.00º,V=10122.7(3)Å³,Z=2,R ₁=0.0369,wR ₂= 0.1005. The synthesis of the antimony tungstate material with simultaneous dysprosium ion and antimony ion bridging adopts a step-by-step assembly strategy and utilizes the prepared precursor Na₉[B‑α‑SbW₉O₃₃]∙19.5H₂O, dimethylamine hydrochloride, antimony trichloride solution and Dy (NO)₃)₃∙6H₂The O is obtained by reaction under the traditional aqueous solution condition, and has simple steps and lower cost. The research of the invention finds that the antimony tungstate material with simultaneous bridging of dysprosium ions and antimony ions can be used for exploring the phenomenon of luminescent sensitization of antimony tungstate fragments to dysprosium ions and the difference of dysprosium ionsf–fThe sensitization effect of the transition is a luminescent material with potential application.

Description

Antimony tungstate material with dysprosium ions and antimony ions bridged simultaneously, and preparation method and application thereof

Technical Field

The invention belongs to the technical field of preparation of polyoxometallate chemical materials, and particularly relates to an antimony tungstate material with dysprosium ions and antimony ions bridged simultaneously, a preparation method thereof and application thereof in the field of luminescence.

Background

Rare earth-substituted polyoxometallate materials have become a hotspot of research in recent years due to their abundant and diverse structural types and compositions and the vast development space in the fields of applications of optics, materials science, chemistry, magnetism, etc. (see a. Dolbecq, e. Dumas, c.r. Mayer, p. Mialane,Chem. Rev. 2010, 110, 6009-6048). Because polyoxometallate is a widely recognized transition metal oxygen cluster, its characteristics can maintain self-stability and skeleton integrity in aqueous solution or in solid state, and possesses a huge oxygen-rich surface and interesting electronic properties, making it an excellent inorganic polydentate ligand (see a. Blazevic, a. Rompel).Coord. Chem. Rev. 2016, 307, 42-64). The three-position Keggin polyoxometallate fragments with clear vacant sites are more excellent as inorganic multidentate ligands, such as some representative three-position Keggin fragments: [ B-alpha-XW ] containing lone electron pairs₉O₃₃]ⁿ⁻ (X = Se^IV、Te^IV，n = 8；As^III、Sb^III、Bi^IIIN = 9) fragment and [ B- α -XW without lone pair₉O₃₄]ⁿ⁻ (X = P^V、As^V，n = 9；Si^IV、Ge^IVN = 10) fragment (see h. Liu, c. Qin, y.g. Wei, l. Xu, g.g. Gao, f.y. Li, x.s. Qu.Inorg. Chem. 2008, 47, 4166-4172). The vacancy antimony tungstate fragment has high negative charge and strong nucleophilicity, is easy to combine with rare earth ions to form rare earth substituted antimony tungstate materials with various structures, and trivalent antimony ions can also be used as metal bridging atoms to form rare earth ions and antimony ions which are commonly bridged to form the antimony tungstate material. For example, Gouzecrh et al reported that one example of antimony ion and cerium ion linked four [ B- α -SbW ] ions in 2002₉O₃₃]⁹⁻Fragmented formation of Tetrapoly antimony tungstate Material (NH)₄)₁₉[(SbW₉O₃₃)₄{WO₂(H₂O)}₂Ce₃(H₂O)₈(Sb₄O₄)]·48H₂O (see g.l. Xue, j. Vaissermann, p. Gouzerh.J. Clust. Sci. 2002, 13, 409-421). In 2016, Reinoso task group reported a series of organic-inorganic hybrid transition and rare earth heterometal substituted antimony tungstate materials Na₁₇[Sb₇W₃₆O₁₃₃Ln₃M₂(OAc)(H₂O)₈]·72H₂O (Ln = La³⁺−Gd³⁺，M = Co²⁺; Ln = Ce³⁺, M = Ni²⁺、Zn²⁺) Wherein a part of the antimony ions also act as bridging atoms (see b. arttexe, s. Reinoso, l.s. felics, l. Lezama, j.m. Gutierrez-Zorrilla, c. Vicent, f. Haso, t. Liu).Chem. Eur. J. 2016, 22, 4616-4625). Professor Longyansheng in 2017Subject group reports a series of organic-inorganic hybrid transition and rare earth hetero metal substituted antimony tungstate materials Na₁₇[Ln₃(H₂O)₅Ni(H₂O)₃(Sb₄O₄)(SbW₉O₃₃)₃(NiW₆O₂₄)(WO₂)₃(CH₃COO)]·(H₂O)₆₅ [Ln = La³⁺、Pr³⁺、Nd³⁺](see J.Cai, X.Y. Zheng, J.Xie, Z.H. Yan, X.J. Kong, Y.P. Ren, L.S. Long, L.S. Zheng.Inorg. Chem. 2017, 56, 8439–8445)。

At present, the research on the luminescent property of rare earth substituted antimony tungstate material and the luminescent sensitization of antimony tungstate fragments to rare earth ions is very little, and the difference of the antimony tungstate fragments to the rare earth ionsf−fThe difference of the sensitization effect of the emission is not reported, so that the design and the detection of the fluorescence property of the synthesized rare earth substituted antimony tungstate luminescent material are necessary. Based on the bridging action of rare earth ions and antimony ions and the idea that the antimony tungstate material can be applied to the field of luminescence, the invention synthesizes an antimony tungstate material with dysprosium ions and antimony ions bridged simultaneously for the first time, and carries out systematic research on the luminescence property and the energy transfer process from antimony tungstate fragments to dysprosium ions; it is noteworthy that the antimony tungstate fragments were found for the first time to be different for dysprosium ionsf−fDifferences in the sensitizing effect of the emission.

Disclosure of Invention

The invention aims to provide an antimony tungstate material with dysprosium ions and antimony ions bridged simultaneously, which can show the phenomenon of energy transfer from antimony tungstate fragments to dysprosium ions in molecules and has potential application value in the field of luminescent materials.

The invention also provides a preparation method and a luminous performance research of the antimony tungstate material with simultaneous bridging of dysprosium ions and antimony ions.

In order to achieve the purpose, the invention adopts the following technical scheme:

antimony tungstic acid with dysprosium ions and antimony ions bridged simultaneouslyA salt material having the formula: [ H ]₂N(CH₃)₂]₈Na₆H₈{[Dy₄(H₂O)₆Sb₆O₄](SbW₁₀O₃₇)₂(SbW₈O₃₁)₂}·24H₂O。

The preparation method of the antimony tungstate material with simultaneous bridging of dysprosium antimony ions and antimony ions is synthesized by a step-by-step assembly method and comprises the following specific steps:

1) synthesizing a precursor Na according to a method reported in the literature in the field₉[B-α-SbW₉O₃₃]·19.5H₂O (see in particular literature (baby, m.; los, i.; Pohlmann, h.; Krebs, B).Chem. Eur. J. 1997, 3, 1232−1237）；

2) The preparation method of the antimony trichloride solution is that solid antimony trichloride salt is dissolved into 6 mol/L hydrochloric acid to obtain a solution;

3) under the condition of stirring, adding Na₉[B-α-SbW₉O₃₃]∙19.5H₂Dissolving O and dimethylamine hydrochloride in distilled water, adding antimony trichloride solution, adjusting pH of the reaction system to 5.40-5.80, and adding Dy (NO)₃)₃∙6H₂And after O, adjusting the pH value of the reaction system to 5.40-5.80 again, stirring for 0.5-1 h, finally placing in a water bath at 85-95 ℃ for heating for 0.5-1.5 h, taking out, cooling to room temperature, filtering, and standing the filtrate at room temperature until yellow green needle crystals (generally requiring 1-2 weeks) are separated out, namely the antimony tungstate material.

The preparation method of the antimony tungstate material with dysprosium ions and antimony ions bridged simultaneously is specifically the Na₉[B-α-SbW₉O₃₃]∙19.5H₂O, dimethylamine hydrochloride, antimony trichloride and Dy (NO)₃)₃∙6H₂The molar ratio of O to distilled water is 0.873-0.978: 10.423-14.715: 0.150-0.250: 0.394-0.482: 720-950.

The invention also provides the application of the antimony tungstate material with simultaneous bridging of dysprosium ions and antimony ions as a luminescent material in the field of luminescence.

The invention adopts a stepwise assembly method, and prepares an antimony tungstate material with simultaneous bridging of dysprosium ions and antimony ions by using an antimony tungstate precursor, trivalent antimony ions and dysprosium ions in a certain molar ratio in the presence of an organic solubilizer, namely dimethylamine hydrochloride. During the reaction, dimethylamine hydrochloride as an organic solubilizer can increase Na₉[B-α-SbW₉O₃₃]·19.5H₂Activity of O, reduction of Na₉[B-α-SbW₉O₃₃]·19.5H₂And reacting O with rare earth to generate a precipitate, wherein antimony ions can be used as a bridging unit to form a bridging segment together with dysprosium ions, and the vacancy antimony tungstate segments are connected together, so that the antimony tungstate material with dysprosium ions and antimony ions bridged simultaneously is formed. The research of the invention finds that the antimony tungstate material with simultaneous bridging of dysprosium ions and antimony ions can be used for exploring the phenomenon of luminescent sensitization of antimony tungstate fragments to dysprosium ions and the difference of dysprosium ionsf–fThe sensitization effect of the transition is a luminescent material with potential application.

The invention provides a preparation method of an antimony tungstate material with dysprosium ions and antimony ions bridged simultaneously and a luminescent property research thereof, compared with the prior art, the invention has the following advantages:

1) the molecular structure of the antimony tungstate material with simultaneous bridging of dysprosium ions and antimony ions provided by the invention can be accurately determined by an X-ray single crystal diffraction technology;

2) the antimony tungstate material with simultaneous bridging of dysprosium ions and antimony ions provided by the invention is prepared by a step-by-step assembly method, and the synthesis method is simple and convenient to operate;

3) the antimony tungstate material bridged by the dysprosium ions and the antimony ions simultaneously shows the phenomenon of energy transfer from antimony tungstate fragments to the dysprosium ions in molecules, has high luminous intensity and has potential application value in the aspect of luminescent materials.

Drawings

In FIG. 1, a) is a diagram of a molecular structural unit of a target material, b) is a diagram of structural breakdown of the molecular structural unit, and c) and d) are diagrams of dysprosium in the molecular structural unitBridged fragments of ions and antimony ions and their mode of connection, e) and f) two crystallographically independent Dy1³⁺And Dy2³⁺Eight-coordinated twisted tetragonal antiprism configuration of the ion, g) four Sb³⁺Parallelograms composed of heteroatoms (Sb 1, Sb1A, Sb2, Sb 2A), Sb 1. cndot. Sb2 and Sb 1. cndot. Sb2A at a distance of 7.767 and 10.055. cndot. h) four Dy³⁺A parallelogram formed by ions (Dy 1, Dy1A, Dy2 and Dy 2A), wherein the distance of Dy & Dy is 5.976-6.481A;

FIG. 2, a) is an infrared spectrum of a target material, b) is a graph of the thermal weight loss of the target material;

FIG. 3 is an X-ray powder diffraction pattern of a target material;

FIG. 4 is a solid fluorescence emission spectrum (black curve) and excitation spectrum (grey curve) obtained by monitoring the strongest emission peak at 575 nm for the target material under 268 nm excitation;

FIG. 5 shows fluorescence emission spectra of target materials under the same test conditions under excitation at 268 nm and 450 nm, respectively;

FIG. 6, a) and b) are time-resolved fluorescence spectra obtained from the target material under 268 nm excitation, c) and d) are time-resolved fluorescence spectra obtained from the target material under 450 nm excitation, which are used for showing the relationship between the emission intensity of the target material and the time-resolved fluorescence spectra obtained under 268 nm and 450 nm excitation and comparing the time-resolved fluorescence spectra obtained under 268 nm and 450 nm excitation to illustrate the fact that the antimony tungstate fragment has a Dy-dependent effect³⁺Ion threef−f ⁴F_9/2→⁶H_15/2、⁴F_9/2→⁶H_13/2、⁴F_9/2→⁶H_11/2Differences in the sensitization degree of the transitions;

FIG. 7, a) and b) are diagrams of Dy in target materials obtained under excitation at 268 and 450 nm respectively under the same test conditions³⁺Of ions⁴F_9/2→⁶H_15/2（483 nm）、⁴F_9/2→⁶H_13/2(575 nm) and⁴F_9/2→⁶H_11/2lifetime of (663 nm) luminescence PeakAn attenuation curve;

FIG. 8 shows the intramolecular transition from antimony tungstate fragment to Dy of target material³⁺Energy transfer process energy level diagram of the ion;

FIG. 9 shows that the strongest emission peak of target material is monitored at 575 nm under the excitation of 450 nm (⁴F_9/2→⁶H_13/2) And (4) obtaining an excitation spectrum.

Detailed description of the invention

The present invention is further illustrated by the following specific examples, but the scope of the invention is not limited thereto.

Example 1:

an antimony tungstate material with dysprosium ions and antimony ions bridged simultaneously, which has the chemical formula: [ H ]₂N(CH₃)₂]₈Na₆H₈{[Dy₄(H₂O)₆Sb₆O₄](SbW₁₀O₃₇)₂(SbW₈O₃₁)₂}·24H₂O。

The antimony tungstate material with dysprosium ions and antimony ions bridged simultaneously is synthesized by a stepwise assembly method, and the specific preparation method relates to the following steps:

1) synthesis of solid Na according to the conventional method reported in the literature of the field₉[B-α-SbW₉O₃₃]·19.5H₂O precursors (see in particular literature (baby, m.; los, i.; Pohlmann, h.; Krebs, B).Chem. Eur. J.1997, 3, 1232−1237）；

2) The antimony trichloride solution was prepared by dissolving solid antimony trichloride salt (4.566 g, 0.020 mol) to 6 mol. L^–1Hydrochloric acid (20 mL);

3) under the condition of stirring, adding Na₉[B-α-SbW₉O₃₃]·19.5H₂O (2.600 g, 0.908 mmol) and dimethylamine hydrochloride (1.000 g, 12.262 mmol) were dissolved in 15 mL of distilled water, and after stirring, antimony trichloride solution (0.25 mL, 0.25 mmol) was added thereto in an amount of 6 mol. L^–1Adjusting pH to 5.60, adding Dy (NO)₃)₃·6H₂O (0.200 g, 0.438 mmol), and 6 mol. L^–1Adjusting the pH value to 5.60 by NaOH, stirring for 0.5 h, finally placing in a water bath at 90 ℃ for heating for 1h, taking out, cooling to room temperature, filtering, standing the filtrate at room temperature for slow evaporation, and separating out a yellowish green needle crystal which is the antimony tungstate material after about 7 days. Yield: 0.14 g (as SbCl)₃Calculated yield 28.5%).

Example 2:

an antimony tungstate material with dysprosium ions and antimony ions simultaneously connected has a chemical formula: [ H ]₂N(CH₃)₂]₈Na₆H₈{[Dy₄(H₂O)₆Sb₆O₄](SbW₁₀O₃₇)₂(SbW₈O₃₁)₂}·24H₂O。

3) under the condition of stirring, adding Na₉[B-α-SbW₉O₃₃]·19.5H₂O (2.500 g, 0.873 mmol) and dimethylamine hydrochloride (0.850 g, 10.423 mmol) were dissolved in 13 mL of distilled water, and after stirring the solution well, antimony trichloride solution (0.15 mL, 0.15 mmol) was added thereto in an amount of 6 mol. L^–1Adjusting pH to 5.70, adding Dy (NO)₃)₃·6H₂O (0.180 g, 0.394 mmol), and 6 mol. L^–1Adjusting pH to 5.70 with NaOH, stirring for 0.5 h, and placing in water bath at 90 deg.CHeating for 1h, taking out, cooling to room temperature, filtering, standing the filtrate at room temperature, slowly evaporating, and obtaining a yellow-green needle crystal which is the antimony tungstate material after about 7 days. Yield: 0.08 g (as SbCl)₃Calculated yield 27.1%).

Example 3:

3) under the condition of stirring, adding Na₉[B-α-SbW₉O₃₃]·19.5H₂O (2.800 g, 0.978 mmol) and dimethylamine hydrochloride (1.200 g, 14.715 mmol) were dissolved in 17 mL of distilled water, and after stirring, antimony trichloride solution (0.25 mL, 0.25 mmol) was added thereto in an amount of 6 mol. L^–1Adjusting pH to 5.40, adding Dy (NO)₃)₃·6H₂O (0.220 g, 0.482 mmol), and 6 mol. L^–1Adjusting the pH value to 5.40 by NaOH, stirring for 0.5 h, finally placing in a water bath at 90 ℃ for heating for 1h, taking out, cooling to room temperature, filtering, standing the filtrate at room temperature for slow evaporation, and obtaining a yellowish green needle crystal which is the antimony tungstate material after about 7 days. Yield: 0.16 g (as SbCl)₃Calculated yield 32.6%).

The crystal structure of the target antimony tungstate material prepared in the above embodiment is determined and characterized, and the unit cell parameters are as follows:

target Material [ H₂N(CH₃)₂]₈Na₆H₈{[Dy₄(H₂O)₆Sb₆O₄](SbW₁₀O₃₇)₂(SbW₈O₃₁)₂}·24H₂O is a monoclinic system, and,P2(1)/nspace group, cell parametersa =13.0803(2) Å，b = 40.6206(8) Å，c = 19.3144(3) Å，α = 90.00º，β = 99.4600(10)º，γ = 90.00 º, V = 10122.7(3) Å³, Z = 2, R ₁ = 0.0369, wR ₂= 0.1005. The molecular unit (see FIG. 1 a) comprises two-site defects [ B-α-SbW₁₀O₃₇]^11–Fragment, two four-defect sites [ B-α-SbW₈O₃₁]^11–Fragment and a [ Dy₄(H₂O)₆Sb₆O₄]²²⁺Cluster (fig. 1 b). [ Dy ]₄(H₂O)₆Sb₆O₄]²²⁺(FIG. 1 c) the clusters can be seen as two separate and identical [ Dy₂(H₂O)₃Sb₃O₂]¹¹⁺Cluster (FIG. 1 d) in which Dy1³⁺And Dy2³⁺Two octadentate twisted tetragonal antiprism configurations (FIG. 1e, f) exhibiting two slightly different coordination environments, four Sb³⁺In the parallelogram formed by heteroatoms (Sb 1, Sb1A, Sb2, Sb 2A) (FIG. 1 g), Sb 1. cndot. Sb2 and Sb 1. cndot. Sb2A are at distances 7.767 and 10.055A, while four Dy are³⁺In a parallelogram formed by ions (Dy 1, Dy1A, Dy2 and Dy 2A) (FIG. 1 h), the distance between Dy and Dy is 5.976-6.481A.

The present invention analyzes the infrared spectrum (fig. 2 a), the thermogravimetric curve (fig. 2 b) and the X-ray powder diffraction (fig. 3) of the target material. As shown in FIG. 2a, the infrared spectrum is at a low wavelengthSeveral segments of 1000-500 cm^–1Four characteristic peaks 934, 878, 778 and 715 cm appear^–1Respectively due to two defect sites Keggin type [ B-α-SbW₁₀O₃₇]^11–Unit and four-vacancy Keggin type [ B-α-SbW₈O₃₁]^11–Upper W-O_t、W−O_b、W−O_cAnd Sb-O_aAsymmetric stretching vibration of the key. At 3439 cm^–1And 1634 cm^–1The two strong absorption peaks are attributed to lattice water and coordinated waterν(H-O) stretching vibration and bending vibration at 1463 cm^–1Shows a weak absorption peak in dimethylamine hydrochloride cationν(C-H) absorption peak of stretching vibration. Figure 2b shows that the target material underwent a two-step weight loss, the first step from 25-161 ℃ by 4.84% (theoretical 4.58%) due to the loss of 24 crystalline and 6 coordinated water molecules; the second step lost 10.10% weight from 161-1000 deg.C (theoretical 10.25%) due to the release of 8 dimethylamine molecules, 16 protons H⁺And four WO₃Sublimation of (2). The X-ray powder diffraction experimental pattern of fig. 3 is substantially identical to the theoretical pattern fitted to single crystal diffraction, indicating that the experimentally synthesized sample is pure.

At present, in the research on rare earth substituted antimony tungstate material, although reports on qualitative research on energy transfer phenomenon in the luminescence process are available, the difference of antimony tungstate fragment to rare earth is researchedf–fThe degree of sensitization of the transition has not been reported. Therefore, we can compare the antimony tungstate fragment and Dy in the target material³⁺Energy transfer between ions and the pair of fragments of antimony tungstate³⁺Three of ionf−fTransition (1)⁴F_9/2→⁶H_15/2、⁴F_9/2→⁶H_13/2、⁴F_9/2→⁶H_11/2) The degree of sensitization was systematically investigated.

Under 268 nm excitation, the UV-visible solid-state fluorescence emission spectrum (FIG. 4) of the target material shows a broad emission band in the range of 350-470 nm, which is attributed to antimony-tungstenOf acid salt fragments³T_1u→¹A_1gTransition, at 483: (⁴F_9/2→⁶H_15/2）、575（⁴F_9/2→⁶H_13/2）、663（⁴F_9/2→⁶H_11/2) Shows Dy at nm³⁺Three characteristic emission peaks of the ion. While the excitation spectrum obtained by monitoring at 575 nm showed five excitation peaks at 268, 352, 366, 389, 427 and 453 nm, which are respectively assigned to the antimony tungstate fragment¹A_1g→¹T_1uTransition, Dy³⁺Ion(s)f−fIs/are as follows⁶H_15/2→⁶P_7/2、⁶H_15/2→⁶P_5/2、⁶H_15/2→⁶I_13/2、⁶H_15/2→⁶G_11/2And⁶H_15/2→⁶I_15/2transition; broad emission band (350) of antimony tungstate fragments–470 nm) and Dy³⁺These five excitation peaks of the ions overlap, indicating that a portion of the energy can be reabsorbed from the antimony tungstate fragment by radiation³T_1u→¹A_1gTransition to Dy³⁺Ion(s)f−fIs/are as follows⁶H_15/2→⁶P_7/2、⁶H_15/2→⁶P_5/2、⁶H_15/2→⁶I_13/2、⁶H_15/2→⁶G_11/2And⁶H_15/2→⁶I_15/2and (4) transition.

By comparing the emission spectra obtained at 268 and 450 nm excitation (FIG. 5), both show three emission peaks at 483, 575 and 663 nm, respectively due to Dy³⁺Ion(s)f−fIs/are as follows⁴F_9/2→⁶H_15/2、⁴F_9/2→⁶H_13/2And⁴F_9/2→⁶H_11/2and (4) transition. At 268 nm (¹A_1g→¹T_1u) Under the condition of excitation, the magnetic field is excited,I(⁴F_9/2→⁶H_15/2) /I(⁴F_9/2→⁶H_13/2) /I(⁴F_9/2→⁶H_11/2) At 450 nm of (5.01: 5.09: 1.00: (⁶H_15/2→⁶I_15/2) The intensity ratio of the three emission peaks under excitation is 2.65: 5.00: 1.00. It is clear that Dy under 268 nm excitation³⁺The peak emission intensity of the ion is significantly higher than that under 450 nm excitation, indicating that Dy can be achieved using excitation wavelengths of the antimony tungstate fraction³⁺Ion(s)f−fThe emission peak intensity of (a) is enhanced. But Dy³⁺Each of the ionsf−fThe degree of peak enhancement varied and the intensity ratio data indicated that of the antimony tungstate fragments³T_1u→¹A_1gTransition transfer to Dy³⁺Of ions⁴F_9/2→⁶H_15/2The energy of the transition is at its maximum, transferred to⁴F_9/2→⁶H_13/2The energy of the transition is then transferred to⁴F_9/2→⁶H_11/2The energy of the transition is the least.

Data analysis showed that under 268 nm excitation, the antimony tungstate fragments were at 470 (C), (D) and (D) respectively by measuring the time-resolved fluorescence spectra of the target material under 268 nm and 450 nm excitation (FIGS. 6 a-d)³T_1u→¹A_1g) Emission peak at nm and Dy³⁺Ions at 480: (⁴F_9/2→⁶H_15/2)、575 (⁴F_9/2→⁶H_13/2) And 660 (⁴F_9/2→⁶H_11/2) The emission peaks at nm all started to rise from 106.8 μ s and reached the maximum at 110.0 μ s, while the time periods from the decay of the emission peaks at 470, 480, 575 and 660 nm to the disappearance from the maximum were 109.2-120.0, 110.0-435.0, 110.0-383.0 and 110.0-162.0 μ s, respectively, indicating that Dy is sensitized with antimony tungstate fragments³⁺Of ions⁴F_9/2→⁶H_15/2And⁴F_9/2→⁶H_13/2of transitionsAttenuation is suppressed, i.e. antimony tungstate to Dy³⁺Energy transfer processes of the ions are present (fig. 6a, 6 b). And Dy is excited at 450 nm³⁺Ions at 480: (⁴F_9/2→⁶H_15/2)、575 (⁴F_9/2→⁶H_13/2) And 660 (⁴F_9/2→⁶H_11/2) The time periods during which the emission peaks at nm rise from the beginning to the maximum are all 107.0-110.0. mu.s, while the time periods during which the emission peaks at 480, 575 and 660 nm decay from the maximum to the disappearance are 110.0-142.0, 110.0-146.0 and 110.0-119.0. mu.s, respectively (FIGS. 6c, 6 d). By comparing the data obtained at 268 nm excitation with the data obtained at 450 nm excitation, it was found that the antimony tungstate fragment was responsible for Dy³⁺Sensitization of ions, Dy³⁺Ions at 480: (⁴F_9/2→⁶H_15/2)、575 (⁴F_9/2→⁶H_13/2) And 660 (⁴F_9/2→⁶H_11/2) The attenuation of the emission peak at nm is inhibited, the inhibition degrees are different, the attenuation of the emission peak at 480 nm is inhibited the most, the attenuation of the emission peak at 575 nm is inhibited the second time, the attenuation of the emission peak at 660 nm is inhibited the least, namely, the antimony tungstate fragment transfers energy to Dy³⁺Ion, Dy³⁺Of ions⁴F_9/2→⁶H_15/2With transition from antimony tungstate fragment³T_1u→¹A_1gThe energy gained by the transition is at its maximum,⁴F_9/2→⁶H_13/2the energy obtained by the transition is the next to,⁴F_9/2→⁶H_11/2the energy gained by the transition is minimal.

To further determine the antimony tungstate fragment pair Dy³⁺Difference of ionf−fSensitization of transitions, Dy obtained under excitation at 268 and 450 nm³⁺The lifetimes of the three emission peaks of the ions are shown in figures 7a and 7 b. The average lifetimes of these three transitions at 268 nm excitation were 43.30, 37.84, and 10.40 μ s, respectively, with a ratio of the three lifetimes of 4.16: 3.64: 1.00. While excitation at 450 nmThe average lifetimes of the next three transitions were 4.51, 5.26 and 4.55 μ s, respectively, with a ratio of the three lifetimes of 0.99: 1.16: 1.00. Dy compared with 268 nm excitation of antimony tungstate fragment under 450 nm excitation³⁺Of ions⁴F_9/2→⁶H_15/2、⁴F_9/2→⁶H_13/2And⁴F_9/2→⁶H_11/2the average lifetime of the transition is significantly extended,⁴F_9/2→⁶H_15/2the service life of the catalyst is prolonged to 9.6 times of the original service life,⁴F_9/2→⁶H_13/2the service life of the catalyst is prolonged to 7.2 times of the original service life,⁴F_9/2→⁶H_11/2the lifetime of the antimony tungstate fragment is prolonged to 2.3 times, and thus it can be found that the antimony tungstate fragment emits light⁴F_9/2→⁶H_15/2The degree of sensitization of the transition is maximized,⁴F_9/2→⁶H_13/2in the next place, the first step is,⁴F_9/2→⁶H_11/2having minimal transition, i.e. indicating antimony tungstate segments³T_1u→¹A_1gTransition transfer to Dy³⁺Of ions⁴F_9/2→⁶H_15/2The energy of the transition is at its maximum, transferred to⁴F_9/2→⁶H_13/2The energy of the transition is then transferred to⁴F_9/2→⁶H_11/2The energy of the transition is the least.

Table 1 energy difference between the energy levels in the target material.

Table 1 shows the antimony tungstate fragments³T_1u→¹A_1gTransition, Dy³⁺Of ions⁴F_9/2→⁶H_15/2、⁴F_9/2→⁶H_13/2And⁴F_9/2→⁶H_11/2energy difference of transition, find⁴F_9/2→⁶H_15/2Energy difference of (1) and³T_1u→¹A_1gis the closest to the point of arrival of the first,⁴F_9/2→⁶H_11/2and³T_1u→¹A_1gthe difference is maximum, which shows that the larger energy level matching degree can improve the dysprosium ion pair of the antimony tungstate fragmentsf−fThe degree of sensitization of the transition. From the energy transfer process level diagram (FIG. 8), it was found that the electron absorption energy from the ground state under O → W LMCT excitation (268 nm) ((¹A_1g) Transition to a higher energy state (¹T_1u) Then relaxes to³T_1uState in which part of the energy is reabsorbed by radiation³T_1u→¹A_1gThe transition is transferred to Dy³⁺Is/are as followsf−f ⁶H_15/2→⁶P_7/2、⁶H_15/2→⁶P_5/2、⁶H_15/2→⁶I_13/2、⁶H_15/2→⁶G_11/2And⁶H_15/2→⁶I_15/2transition, part of energy is transferred to⁴F_9/2→⁶H_15/2、⁴F_9/2→⁶H_13/2And⁴F_9/2→⁶H_11/2transition, part of the energy returning to ground state by radiative decay (¹A_1g）。

FIG. 9 shows five excitation peaks at 352, 366, 389, 427 and 450 nm, respectively, assigned to Dy³⁺Of ions⁶H_15/2→⁶P_7/2、⁶H_15/2→⁶P_5/2、⁶H_15/2→⁶I_13/2、⁶H_15/2→⁶G_11/2And⁶H_15/2→⁶I_15/2and (4) transition.

In summary, fig. 4 to 9 collectively demonstrate the presence of fragments of antimony tungstate to Dy in the target material molecule³⁺Energy conversion of ionsShift phenomenon, relative to that at 450: (⁶H_15/2→⁶I_15/2) The emission peak intensity of dysprosium ion obtained under nm excitation is 268 (³T_1u→¹A_1g) Dy obtained under nm excitation³⁺Of ionsf−fThe emission intensity is obviously enhanced, the service life is obviously prolonged, and the antimony tungstate fragment pair Dy³⁺Of ions⁴F_9/2→⁶H_15/2The maximum sensitization of the transition, to⁴F_9/2→⁶H_13/2Sensitization of the transition to a lesser degree⁴F_9/2→⁶H_11/2Sensitization of the transition is minimal. The target material is an antimony tungstate oxysalt luminescent material with potential application value and simultaneously embedded rare earth and antimony ions.

Claims

1. An antimony tungstate material with dysprosium ions and antimony ions bridged simultaneously, which has the chemical formula: [ H ]₂N(CH₃)₂]₈Na₆H₈{[Dy₄(H₂O)₆Sb₆O₄](SbW₁₀O₃₇)₂(SbW₈O₃₁)₂}·24H₂O；

The material is a monoclinic system,P2(1)/nspace group, cell parametersa =13.0803(2) Å，b = 40.6206(8) Å，c= 19.3144(3) Å，α = 90.00º，β = 99.4600(10)º，γ = 90.00 º, V = 10122.7(3) Å³, Z= 2, R ₁ = 0.0369, wR ₂= 0.1005; the molecular unit comprises two defect sites [ B-α-SbW₁₀O₃₇]^11–Fragment, two four-defect sites [ B-α-SbW₈O₃₁]^11–Fragment and a [ Dy₄(H₂O)₆Sb₆O₄]²²⁺And (4) clustering.

2. The method for preparing the antimony tungstate material with simultaneous bridging of dysprosium antimony ions and antimony ions as recited in claim 1, which is characterized by comprising the following steps:

under the condition of stirring, adding Na₉[B-α-SbW₉O₃₃]∙19.5H₂Dissolving O and dimethylamine hydrochloride in distilled water, adding antimony trichloride solution, adjusting pH of the reaction system to 5.40-5.80, and adding Dy (NO)₃)₃∙6H₂And after O, adjusting the pH value of the reaction system to 5.40-5.80 again, stirring for 0.5-1 h, finally heating in a water bath at 85-95 ℃ for 0.5-1.5 h, taking out, cooling to room temperature, filtering, and standing the filtrate at room temperature until yellow green needle crystals are separated out, namely the antimony tungstate material.

3. The method for preparing an antimony tungstate material in which dysprosium ions and antimony ions are simultaneously bridged as claimed in claim 2, wherein the Na is₉[B-α-SbW₉O₃₃]∙19.5H₂O, dimethylamine hydrochloride, antimony trichloride and Dy (NO)₃)₃∙6H₂The molar ratio of O to distilled water is 0.873-0.978: 10.423-14.715: 0.150-0.250: 0.394-0.482: 720-950.

4. Use of an antimony tungstate material in which dysprosium ions and antimony ions are simultaneously bridged as defined in claim 1 as a luminescent material in the field of luminescence.