Viologen-niobium polyacid-based supramolecular framework material as well as preparation method and application thereof

Abstract

The invention discloses a viologen-niobium polyacid group supramolecular framework material as well as a preparation method and application thereof, the molecular formula of the viologen-niobium polyacid group supramolecular framework material is H84 (HG) 12 {(H2PAV) 12 [K8Nb96O288]} {(HG) 12 (H2PAV) 6 [KNb24O72] 4}. Solvent, PAV = Propyramino virogen, G = Guanidine, and solvent = 338H2O, and the formula of the viologen-niobium polyacid group supramolecular framework material is shown in the description. The viologen-niobium polyacid group supramolecular framework is a multi-stage assembled three-dimensional open framework and is structurally characterized in that a three-wheel cluster {KNb24O72} is used as a primary structure, the three-wheel cluster {KNb24O72} and K < + > are assembled into a cage A {K12Nb96} through ionic bonds, the three-wheel cluster {KNb24O72} and guanidinium are assembled into a cage B {G12K4Nb96} through hydrogen bonds, the cage A and the cage B of a secondary structure are connected with each other through hydrogen bonds of the other group of guanidinium to form the PCU topological three-dimensional open framework, and the three-wheel cluster {KNb24O72} and the guanidinium are mutually connected through hydrogen bonds of the other group of guanidinium. The electron-rich skeleton continues to anchor aminopropyl viologen through a hydrogen bond to form a final structure.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of new materials, and particularly relates to a viologen-niobium polyacid-based supramolecular framework material and a preparation method and application thereof. BACKGROUND

[0002] Open framework materials are widely concerned in the fields of host-guest chemistry and energy catalysis due to their excellent porosity and designability. Due to the high specific surface area and developed internal pores, the mass transfer and pre-enrichment of guest molecules are facilitated, and the open framework materials have an innate advantage in sensing and detection. Compared with traditional covalent frameworks, the supramolecular frameworks reported in recent years have excellent crystallinity, self-repairing property and mild generation conditions, and are considered as one of the future directions of functional materials.

[0003] Viologen (4,4'-bipyridinium quaternary salt) is a kind of organic compound with redox activity, and is widely studied as an active unit due to its reversible color change (V 2+ ←—→V ·+) in the process of electron transfer. A large number of stimulus-responsive materials have been developed. However, simple viologen-based materials have the disadvantages of poor cycling performance and poor alkaline stability. From the perspective of practical application, it is imperative to design the second component to improve the robustness of the compound. As an important branch of classic inorganic clusters-polyoxometalates (POMs), niobium polyacid is often used in framework material construction due to its clear structure and unique physicochemical properties. The high surface negative charge and alkaline stability make niobium polyacid building blocks an ideal candidate for the second component. By utilizing the complementary properties of the electron-deficient viologen and the electron-rich niobium polyacid, the two can be cooperatively assembled to produce novel sensing materials.

[0004] Based on the above needs, a {Nb 24} cluster and an aminopropyl viologen onium ion are assembled by hydrogen bonding to design a viologen-niobium polyacid-based supramolecular framework with three-dimensional channels. Through the synergistic effect between inorganic and organic building blocks, the compound exhibits good structural robustness and sensitive stimulus responsiveness. It has potential applications in the fields of photochromism and organic detection. SUMMARY

[0005] To solve the above problems, the application provides a viologen-niobium polyacid-based supramolecular framework material and a preparation method and application thereof.

[0006] To achieve the above object, the application adopts the following technical scheme:

[0007] A viologen-niobium polyacid-based supramolecular framework material, the molecular formula of the viologen-niobium polyacid-based supramolecular framework material is: H 84 (HG) 12 {(H2PAV) 12[K8Nb 96 O 288 ]}{(HG) 12 (H2PAV)6[KNb 24 O 72 ]4}·solvent, wherein, PAV = Propylamino viologen, G = Guanidine, solvent = 338H2O; the viologen-niobate-based supramolecular framework is a three-dimensional open framework of multi-level assembly, and the structural characteristics are: the three-wheel cluster {KNb 24 O 72} as a primary structure, and the K + is assembled into cage A {K 12 Nb 96}, and the guanidinium is assembled into cage B {G 12 K4Nb 96} through hydrogen bonds, the secondary structure cage A and cage B are connected to each other by hydrogen bonds of another group of guanidinium, forming a three-dimensional open framework of PCU topology, and the electron-rich skeleton continues to anchor the aminopropyl viologen through hydrogen bonds to form the final structure.

[0008] Preferably, the pore size of the viologen-niobate-based supramolecular framework material is 0.6*0.6 nm, and the porosity is 31%.

[0009] Preferably, the viologen-niobate-based supramolecular framework material is crystallized in a cubic system, space group No. 215.

[0010] Preferably, the unit cell parameters of the viologen-niobate-based supramolecular framework material are: α = β = γ = 90°.

[0011] A preparation method of a viologen-niobate-based supramolecular framework material, comprising the following steps:

[0012] S1, synthesizing niobate precursor K7HNb6O 19 ·13H2O, and synthesizing aminopropyl viologen hydrobromide;

[0013] S2, adding the niobate precursor, guanidine hydrochloride, aminopropyl viologen hydrobromide and potassium hydroxide into ionized water in proportion and stirring;

[0014] S3, placing the filtrate for several days to obtain yellow transparent block-shaped crystals;

[0015] S4, centrifugally washing the crystals with deionized water to obtain the viologen-niobate-based supramolecular framework material.

[0016] Preferably, in step S2, the niobate precursor 22.50 g, guanidine hydrochloride 0.75 g, aminopropyl viologen hydrogen dibromide 24.00 g, and potassium hydroxide 0.60 g are sequentially added into 450 mL of deionized water under stirring.

[0017] Preferably, in step S2, after adding each raw material into the deionized water, the mixture is stirred for at least 5 minutes, and the total stirring time is 1 hour.

[0018] Preferably, in step S3, the clear liquid is filtered out with cotton, and is left to stand in an open crystallizing dish for 5-10 days.

[0019] The application of the viologen-niobium polyacid-based supramolecular framework material as a detection material in the field of new material technology.

[0020] After the above technical solution is adopted, the application has the following beneficial effects: the viologen-niobium polyacid-based supramolecular framework material has high structural robustness, and does not undergo irreversible collapse of the pore after removal of the guest; it has strong acid and alkali resistance, and maintains structural stability within a working range of pH = 2-13. The viologen-niobium polyacid-based supramolecular framework material has photochromic ability, exhibits discoloration response to aniline guests, has simple synthesis steps, high product purity, and can be prepared in kilograms, has potential as a sensing and detection material, and has good application prospects. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 A crystal morphology graph of the viologen-niobium polyacid-based supramolecular framework material prepared in the application under an optical microscope;

[0022] Figure 2 A packing mode and a topological graph of the viologen-niobium polyacid-based supramolecular framework material prepared in the application;

[0023] Figure 3 A structural graph of the viologen-niobium polyacid-based supramolecular framework material prepared in the application;

[0024] Figure 4 A powder diffraction spectrum of the viologen-niobium polyacid-based supramolecular framework material prepared in the application;

[0025] Figure 5 An infrared spectrum of the viologen-niobium polyacid-based supramolecular framework material prepared in the application;

[0026] Figure 6 An ultraviolet-visible diffuse reflectance spectrum of the viologen-niobium polyacid-based supramolecular framework material prepared in the application;

[0027] Figure 7 A pH-dependent powder diffraction spectrum of the viologen-niobium polyacid-based supramolecular framework material prepared in the application;

[0028] Figure 8 Powder diffraction spectrum of the purpurin-niobium polyacid-based supramolecular framework material prepared in the application after heat treatment and corresponding self-repairing;

[0029] Figure 9 Water vapor adsorption curve and powder diffraction spectrum of the purpurin-niobium polyacid-based supramolecular framework material prepared in the application after adsorption test;

[0030] Figure 10 Color change mechanism principle diagram of the purpurin-niobium polyacid-based supramolecular framework material prepared in the application under three different conditions;

[0031] Figure 11 Powder diffraction spectrum of the purpurin-niobium polyacid-based supramolecular framework material prepared in the application after soaking;

[0032] Figure 12 Color change diagram of the purpurin-niobium polyacid-based supramolecular framework material prepared in the application after soaking in an organic solvent;

[0033] Figure 13 Time-resolved ultraviolet-visible absorption spectrum of the purpurin-niobium polyacid-based supramolecular framework material prepared in the application under mercury lamp irradiation and time-resolved ultraviolet-visible absorption spectrum in the dark;

[0034] Figure 14 Color change diagram of the single crystal of the purpurin-niobium polyacid-based supramolecular framework material prepared in the application after mercury lamp irradiation;

[0035] Figure 15 Ultraviolet-visible absorption spectrum change diagram of the purpurin-niobium polyacid-based supramolecular framework material prepared in the application before and after steaming with an organic amine vapor;

[0036] Figure 16 Ultraviolet-visible absorption spectrum change diagram of the purpurin-niobium polyacid-based supramolecular framework material prepared in the application before and after adsorbing aniline and diphenylamine;

[0037] Figure 17 Color change diagram of the purpurin-niobium polyacid-based supramolecular framework material prepared in the application before and after adsorbing aniline and diphenylamine. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the present application clearer and more apparent, the present application will be further described in detail below with examples. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application.

[0039] A preparation method of a purpurin-niobium polyacid-based supramolecular framework material, comprising the following steps:

[0040] S1, synthesis of niobate precursor K7HNb6O 19 • 13H2O, synthesis of aminopropyl viologen hydrobromide;

[0041] S2, niobate precursor 22.50 g, guanidine hydrochloride 0.75 g, aminopropyl viologen hydrobromide 24.00 g, potassium hydroxide 0.60 g were sequentially added into 450 mL of deionized water under stirring; wherein each time after adding one raw material into the deionized water, stirring for at least 5 minutes, and a total stirring time of 1 hour;

[0042] S3, placing and filtering the clear liquid with cotton, and placing in a crystallization dish for 5-10 days to generate yellow transparent block-shaped crystals;

[0043] S4, centrifugal washing the crystals with deionized water to obtain a viologen-niobium polyacid-based supramolecular framework material.

[0044] Characterization and performance test of the material:

[0045] (1) X-ray single crystal diffraction

[0046] Single crystal diffraction data were tested and collected on a Bruker SmartAPEX II diffractometer (anode target: IμS-Mo, detector: APEX II CCD). The diffraction photographs of the compound at 170(2) K were collected by - scanning and ω-scanning. The collected diffraction photographs were processed by APEX 5 software, integrated by SAINT V8.38A program, and corrected by SADABS-2016 / 2 program for multiple scanning absorption. Using Olex2-1.5 software, the initial structure was resolved by Intrinsic Phasing method of Shel-XT 2018 / 2 program, and all non-hydrogen atoms were refined by full-matrix least squares based on F 2 of Shel-XL 2018 / 3 program, and all hydrogen atoms were fixed at ideal positions by a riding model. In addition, the contribution of disordered molecules in the pores which cannot be modeled to the overall diffraction intensity was deducted by SolventMask of Olex2-1.5. The crystallographic parameters of the prepared viologen-niobium polyacid-based supramolecular framework material are shown in Table 1.

[0047] Table 1: Crystallographic parameters of the viologen-niobium polyacid-based supramolecular framework material

[0048]

[0049]

[0050] (2) Powder diffraction characterization:

[0051] Powder X-ray diffraction (PXRD) patterns were collected using a Rigaku Ultima IV diffractometer with Cu Ka radiation The measured powder diffraction patterns were in good agreement with the simulated powder diffraction patterns (simulated based on single crystal data using Mercury) with no impurity phase. The difference in peak intensity for some peaks was due to the preferred orientation of the sample.

[0052] (3) Infrared spectroscopy characterization:

[0053] The infrared spectrum (IR) of the sample was tested on a Nicolet IS50 Fourier transform infrared (FT / IR) spectrometer, mode: attenuated total reflection (ATR). Wavenumber range: 4000-400 cm -1 .

[0054] (4) Thermogravimetric analysis:

[0055] Thermogravimetric analysis (TGA) was performed on a TGA / DSC 3+ analyzer with a heating rate of 5°C / min -1 , nitrogen (N2) atmosphere, and a temperature range of 30-800°C.

[0056] (5) Ultraviolet-visible diffuse reflectance absorption spectroscopy characterization:

[0057] The ultraviolet-visible spectrum was tested by a Shimadzu UV-2600 ultraviolet-visible spectrophotometer using barium sulfate as a reference, with a wavelength range of 200-1200 nm.

[0058] (6) Water vapor adsorption characterization:

[0059] Water vapor adsorption tests were performed on an ASAP-2000 specific surface area pore size analyzer. The sample was first vacuum activated at 60°C for 24 hours, and then water vapor adsorption tests were performed. A total of 3 cycles of testing were performed.

[0060] (7) Photochromic test:

[0061] The photochromic test was performed by irradiating the sample with a CHF-XM500 mercury lamp (irradiance of 110 mW / cm 2 , determined by a light power meter PL-MW2000) for a certain time, and then testing the time-resolved ultraviolet-visible absorption spectrum using a Shimadzu UV-2600 ultraviolet-visible spectrophotometer.

[0062] (8) Guest adsorption-color change test:

[0063] The adsorption-discoloration test is to place the sample in the organic amine vapor for 24 hours or soak in the aniline / diphenylamine dichloromethane solution for 24 hours, and then test with Shimadzu UV-2600 ultraviolet-visible spectrophotometer to obtain the ultraviolet-visible absorption spectrum of the different guest adsorption.

[0064] The characterization of the material and the performance test results are as follows Figures 1 to 17 .

[0065] Figure 1 The crystal morphology graph of the viologen-niobium polyacid-based supramolecular framework material prepared in the application under an optical microscope;

[0066] Figure 2 The packing mode and topological graph of the viologen-niobium polyacid-based supramolecular framework material prepared in the application;

[0067] Figure 3 The structure graph of the viologen-niobium polyacid-based supramolecular framework material prepared in the application;

[0068] Figure 4 The powder diffraction spectrum of the viologen-niobium polyacid-based supramolecular framework material prepared in the application;

[0069] Figure 5 The infrared spectrum of the viologen-niobium polyacid-based supramolecular framework material prepared in the application;

[0070] Figure 6 The ultraviolet-visible diffuse reflectance spectrum of the viologen-niobium polyacid-based supramolecular framework material prepared in the application;

[0071] Figure 7 The pH-dependent powder diffraction spectrum of the viologen-niobium polyacid-based supramolecular framework material prepared in the application;

[0072] Figure 8 The powder diffraction spectrum of the viologen-niobium polyacid-based supramolecular framework material prepared in the application after heat treatment a), and the powder diffraction spectrum after self-repairing b);

[0073] Figure 9 The water vapor adsorption curve of the viologen-niobium polyacid-based supramolecular framework material prepared in the application a), and the powder diffraction spectrum after adsorption test b);

[0074] Figure 10 The discoloration mechanism principle diagram of the viologen-niobium polyacid-based supramolecular framework material prepared in the application under three different conditions;

[0075] Figure 11Powder diffraction spectrum a) of the viologen-niobium polyacid-based supramolecular framework material prepared in the application after soaking in a protic solvent, the soaking solvents are N,N-dimethylformamide, dimethyl sulfoxide, diethyl ether, acetonitrile, isopropanol, ethanol, methanol in turn; powder diffraction spectrum c) after soaking in an aprotic solvent, the soaking solvents are trichloromethane, dichloromethane, toluene, cyclohexane, n-hexane in turn; and the corresponding self-repairing processes b) and d) after adding deionized water respectively;

[0076] Figure 12 Color change graph of the viologen-niobium polyacid-based supramolecular framework material prepared in the application after soaking in an organic solvent; the soaking solvents are N,N-dimethylformamide, dimethyl sulfoxide, diethyl ether, dioxane, acetonitrile, isopropanol, ethanol, methanol, water in turn;

[0077] Figure 13 Time-resolved ultraviolet-visible absorption spectrum a) of the viologen-niobium polyacid-based supramolecular framework material prepared in the application under mercury lamp irradiation, and time-resolved ultraviolet-visible absorption spectrum b) in the dark;

[0078] Figure 14 Color change graph of the single crystal of the viologen-niobium polyacid-based supramolecular framework material prepared in the application after mercury lamp irradiation;

[0079] Figure 15 Ultraviolet-visible absorption spectrum change graph of the viologen-niobium polyacid-based supramolecular framework material prepared in the application before and after fumigation with organic amine vapor; the organic amines are ethylamine, ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, n-propylamine, n-butylamine, tetramethylethylenediamine, tetramethylpropanediamine in turn;

[0080] Figure 16 Ultraviolet-visible absorption spectrum change graph of the viologen-niobium polyacid-based supramolecular framework material prepared in the application before and after adsorbing aniline and diphenylamine; the samples after adsorption are shown in turn as blank, aniline, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine;

[0081] Figure 17 Color change graph of the viologen-niobium polyacid-based supramolecular framework material prepared in the application before and after adsorbing aniline and diphenylamine.

[0082] The above merely provides the preferred but non-limiting embodiments of the present application, and the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A viologen-niobium polyacid-based supramolecular framework material, characterized in that, The molecular formula of the viologen-niobium polyacid-based supramolecular framework material is: H 84 (HG) 12 {(H2PAV) 12 [K8Nb 96 O 288 ]}{(HG) 12 (H2PAV)6[KNb 24 O 72 ]4}·solvent, where PAV = Propylamino viologen, G = Guanidine, solvent = 338H2O; the viologen-niobium polyacid supramolecular framework is a multi-level assembled three-dimensional open framework, characterized by: three-ring clusters {KNb 24 O 72 As a primary structure, it is bonded to K via ionic bonds. + Assemble into cage A{K 12 Nb 96 }, and guanidine assembles into cage B{G} via hydrogen bonds. 12 K4Nb 96 In the secondary structure, cages A and B are interconnected by hydrogen bonds of another set of guanidines, forming a three-dimensional open framework of the PCU topology. The electron-rich skeleton continues to anchor aminopropyl viologen through hydrogen bonds, forming the final structure.

2. The viologen-niobium polyacid-based supramolecular framework material as described in claim 1, characterized in that: The vizigon-niobium polyacid-based supramolecular framework material has a pore size of 0.6 × 0.6 nm and a porosity of 31%.

3. The viologen-niobium polyacid-based supramolecular framework material as described in claim 1, characterized in that: The viologen-niobium polyacid-based supramolecular framework material crystallizes in a cubic crystal system. Space Group No.

215.

4. The viologen-niobium polyacid-based supramolecular framework material as described in claim 1, characterized in that, The cell parameters of the viologen-niobium polyacid-based supramolecular framework material are as follows: α = β = γ = 90°.

5. A method for preparing a viologen-niobium polyacid-based supramolecular framework material as described in any one of claims 1-4, characterized in that, Includes the following steps: S1, Synthesis of niobate precursor K7HNb6O 19 ·13H2O, synthesize aminopropyl viologen hydrobromide; S2. Add the niobate precursor, guanidine hydrochloride, aminopropyl viologen hydrobromide, and potassium hydroxide sequentially to the deionized water and stir. S3. After letting the filtered liquid stand for several days, yellow transparent blocky crystals are obtained. S4. The crystals were washed by centrifugation with deionized water to obtain the vizigon-niobium polyacid-based supramolecular framework material.

6. The method for preparing a viologen-niobium polyacid-based supramolecular framework material as described in claim 5, characterized in that: In step S2, 22.50 g of niobate precursor, 0.75 g of guanidine hydrochloride, 24.00 g of aminopropyl violetine dibromate, and 0.60 g of potassium hydroxide were added sequentially to 450 mL of deionized water under stirring.

7. The viologen-niobium polyacid-based supramolecular framework material as described in claim 6, characterized in that: In step S2, after each raw material is added to the deionized water, the mixture is stirred for at least 5 minutes, for a total of 1 hour.

8. The viologen-niobium polyacid-based supramolecular framework material as described in claim 1, characterized in that: In step S3, filter the clear liquid with cotton and leave it in an open crystallizing dish for 5-10 days.

9. An application of the viologen-niobium polyacid-based supramolecular framework material as described in any one of claims 1-4, characterized in that: The viologen-niobium polyacid-based supramolecular framework material is used as a detection material in the field of new materials technology.

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