CN111116933B

CN111116933B - Supramolecular polymer and application thereof in mercury ion detection

Info

Publication number: CN111116933B
Application number: CN202010006111.9A
Authority: CN
Inventors: 林奇; 李颖洁; 张云飞; 张有明; 姚虹; 魏太保
Original assignee: Northwest Normal University
Current assignee: Northwest Normal University
Priority date: 2020-01-03
Filing date: 2020-01-03
Publication date: 2021-09-24
Anticipated expiration: 2040-01-03
Also published as: CN111116933A

Abstract

The invention discloses a supermolecule polymer, which is prepared by double columns [5] of a main body]Aromatic hydrocarbon and guest pyridinium are heated and dissolved in DMSO-H according to the molar ratio of 1:2₂In the O system, the compound is obtained by the self-assembly of a host and an object. The supramolecular polymer is prepared in DMSO-H₂In O solution, when the excitation wavelength is 400 nm, no fluorescence is emitted. DMSO-H in supramolecular polymers₂Adding Mg into the O solution respectively²⁺,Ca²⁺,Cr³⁺,Hg²⁺,Co²⁺,Ni²⁺,Cu²⁺,Zn²⁺,Pb²⁺,Cd²⁺,Fe³⁺,Ag⁺,Eu³⁺H of (A) to (B)₂O solution, only Hg was found²⁺Can obviously open the fluorescence of the supramolecular polymer, so that the supramolecular polymer can singly and selectively recognize Hg²⁺The lowest detection limit is 1.5549 multiplied by 10^‑6And M. The identification performance has important application value in the field of ion identification.

Description

Supramolecular polymer and application thereof in mercury ion detection

Technical Field

The invention relates to a supermolecule polymer, in particular to a supermolecule polymer composed of double columns [5]]Aromatic hydrocarbons (FAP 5) and pyridinium salts (BN) via hydrogen bonding

Self-assembling to obtain supermolecular polymer; the invention also relates to the application of the supramolecular polymer in detecting Hg in an aqueous solution²⁺Belonging to the field of ion detection.

Background

Mercury can be said to be one of the most toxic heavy metal ions in the environment, and is also one of the water-derived foods. In aqueous solution, bacteria can convert mercury into methyl mercury, an effective neurotoxin, which accumulates in the seafood, entering the food chain. Subsequently, methylmercury problems in humans from seafood and other dietary and environmental sources have been associated with severe sensory, motor, and cognitive disorders. When humans ingest too much food, methylmercury causes a number of serious illnesses, including sensory, motor, and neural injury. Inorganic mercury compounds show severe effects on the heart, kidney, stomach and genes of humans.

Mercury metal is volatile and can move far in air. It is then deposited on land or in water and oxidized to mercury (II). The oxidized inorganic mercury (II) can be converted into organic mercury by microorganisms. Mercury in the environment originates not only from geological events (e.g. volcanic emissions) but also from modern human activities. For example, dental office waste water is a major source of mercury pollution, in part because dentists are free of waste from federal regulations. Despite its high toxicity, mercury has been widely used as a chemical additive and energy source in many industrial applications, including cosmetics, thermometers, batteries, agrochemicals, and fluorescent lamps. Therefore, the development of a comprehensive strategy for real-time sensing and rapid removal of mercury ions is of great significance in material chemistry, chemical engineering and environmental science.

Disclosure of Invention

The invention aims to provide a self-assembled supramolecular polymer which takes a bicolumn [5] arene derivative as a main body and takes pyridinium as an object;

another object of the present invention is to provide the supramolecular polymer for detecting Hg in an aqueous solution²⁺The use of (1).

Preparation of mono-and supramolecular polymers

The supermolecular polymer of the present invention is a main body double column [5]]Aromatic hydrocarbon and guest pyridinium are heated and dissolved in DMSO-H according to the molar ratio of 1:2₂In the O system, the supermolecular polymer obtained by the self-assembly of a host and a guest is marked as FAP 5-BN. Wherein, DMSO-H₂In the O system, DMSO and H₂The volume ratio of O is 1: 2-1: 2.5.

Synthesis of bulk dual column [5] arene FAP 5: using acetonitrile as a solvent, reacting unilateral bromo-column [5] arene and acylhydrazone compound FAN at a molar ratio of 1: 3.3-1: 3.5 at 90-95 ℃ for 45-48 h, performing suction filtration to obtain an orange solid crude product, leaching with dichloromethane to obtain double-column [5] arene, and marking as FAP 5. The structural formula is as follows:

synthesis of guest pyridinium BN: the method comprises the steps of taking an acetonitrile solvent as a solvent, reacting 1, 10-dibromodecane and 4, 4-bipyridine at a molar ratio of 1: 2.3-1: 2.5 at 90-95 ℃ for 20-25 h, and recrystallizing with acetonitrile to obtain a light yellow crystalline solid, namely pyridinium, and marking the solid as BN. The structural formula is as follows:

。

fig. 1 and fig. 2 are hydrogen spectrograms of a main body double column [5] arene FAP5 and a guest pyridinium BN respectively. Indicating that the preparation of the main body double column [5] arene FAP5 and the guest pyridinium BN is successful.

Fig. 3 is a partial nuclear magnetic titration hydrogen spectrum of FAP5 with BN. Wherein (a) FAP5+1equiv. BN; (b) FAP5+2equiv. BN; (c) FAP5+3equiv. BN; (d) FAP5+4equiv. BN; (e) FAP5+5equiv. BN. In DMSO-H₂-NH in the supramolecular polymer host molecule FAP5 in O solution₂Taking the group as a hydrophilic group and the pillar arene as a hydrophobic group, and reacting a guest molecule BN with a host molecule FAP5 in DMSO-H₂And assembling in O solution. As can be seen from the figure, with the addition of the guest molecule BN, the Ha proton peak on the host molecule FAP5 moves to the low field, the Hb proton peak moves to the high field, the H1 proton peak on the guest molecule BN moves to the high field, and the rest proton peaks all move to the low field. This phenomenon illustrates that the guest molecule BN of the supramolecular polymer enters the cavity of the pillared arene and is hydrogen bonded with the host molecule FAP5

The supermolecular polymer FAP5-BN is obtained by action of self-assembly.

Second, supermolecule polymer detects Hg²⁺Application of

1. Fluorescent properties of supramolecular polymers

The research on the fluorescence property of the supramolecular polymer FAP5-BN shows that the supramolecular polymer FAP5-BN in DMSO-H₂The O solution (DMSO with the volume percentage of 25-30%) has good solubility and the concentration of the O solution is 1 multiplied by 10^-5M, the supramolecular polymer does not emit fluorescence when the excitation wavelength is 400 nm (as shown in figure 4).

2. Single selective fluorescence recognition of Hg by supramolecular polymer²⁺

DMSO-H in the supramolecular polymer FAP5-BN₂In O solution (DMSO and H)₂The volume ratio of O is 3: 7),

40 times equivalent (relative to the supramolecular polymer FAP 5-BN) of Mg is added respectively²⁺,Ca²⁺,Cr³⁺,Hg²⁺,Co²⁺,Ni²⁺,Cu²⁺,Zn²⁺,Pb²⁺,Cd²⁺,Fe³⁺,Ag⁺,Eu³⁺H of (A) to (B)₂O solution, only Hg was found²⁺The addition of the cationic group can obviously turn on the fluorescence of the supramolecular polymer FAP5-BN, while the addition of other cations can not obviously change the fluorescence of the supramolecular polymer FAP5-BN, so that the supramolecular polymer FAP5-BN can singly and selectively recognize Hg²⁺(see fig. 5). And through the elimination of the host and the guest, the selective recognition of Hg can be shown only when the host molecule FAP5 is assembled with the guest molecule BN²⁺That Hg cannot be selectively recognized by either the host molecule alone or the guest molecule alone²⁺(see fig. 6).

Meanwhile, in order to avoid the interference of other cations to the experiment, an anti-interference experiment is carried out. The results show that other cations do not interfere with the recognition of the supramolecular polymer FAP5-BN (see fig. 7).

Fluorescence titration experiments show that the supermolecular polymer FAP5-BN is used for Hg²⁺Has a minimum detection limit of 1.5549 × 10^-6M (see FIGS. 8 and 9), indicating that the supramolecular polymer FAP5-BN recognizes Hg²⁺The sensitivity of (2) is high.

3. Analysis of recognition mechanisms

FIG. 10 shows FAP5-BN with Hg²⁺Wherein (1) FAP5+ BN; (2) FAP5+ BN +1equiv²⁺；（3）FAP5+BN +2equiv.Hg²⁺；（4）FAP5+BN +3equiv.Hg²⁺；（5）FAP5+BN +4equiv.Hg²⁺；（6）FAP5+BN +5equiv.Hg²⁺. As can be seen from FIG. 10, as Hg flows²⁺The Ha proton peak on the host molecule FAP5 moves to a high field, and the H proton peak on the guest molecule BN moves to the high field, which indicates that when Hg is added²⁺After addition, the supramolecular polymer formed with the host guest undergoes coordination to form FAP5-BN-Hg with a concomitant change in fluorescence. As can be seen from FIG. 11, when Hg is added²⁺Thereafter, nanovesicles may be formed.

Drawings

Fig. 1 is a hydrogen spectrum of FAP 5.

FIG. 2 is a hydrogen spectrum of BN.

Fig. 3 is a partial nuclear magnetic titration hydrogen spectrum of FAP5 with BN.

FIG. 4 shows FAP5-BN in DMSO-H under different water ratio conditions₂Fluorescence spectrum in O solution.

FIG. 5 shows DMSO-H of FAP5-BN₂Fluorescence full scan (lambda) with different cations added to O solution_ex=400 nm）。

FIG. 6 shows DMSO-H of FAP5-BN, FAP5₂Hg is added into the O solution respectively²⁺Fluorescence map of (lambda)_ex=400 nm）。

FIG. 7 shows DMSO-H of FAP5-BN₂The fluorescence of the O solution to other cations is resistant to interference.

FIG. 8 shows FAP5-BN vs Hg²⁺Fluorescence titration chart of (lambda)_ex=400 nm）。

FIG. 9 identification of Hg for FAP5-BN²⁺The lowest detection limit map of (2).

FIG. 10 shows FAP5-BN with Hg²⁺Nuclear magnetic titration spectrum of (1).

FIG. 11 shows the addition of Hg to FAP5-BN²⁺Transmission electron micrograph (D).

Detailed Description

The preparation and use of the supramolecular polymers of the present invention are further illustrated by the specific examples below.

Example one preparation of supramolecular Polymer FAP5-BN

1. Synthesis of subject FAP5

（1）Z₁The synthesis of (2): to 200ml of acetone were added 4mmol (0.8560g) of 1, 4-dibromobutane and 4mmol KI (0.6641g), and after stirring at room temperature for 30 minutes, 0.1381g K was added₂CO₃(1mmol) and 1mmol of p-methoxyphenol (0.124 g), namely N₂Protecting, heating and refluxing the mixture at 60 deg.C for 72 hr, vacuum filtering while hot, collecting, concentrating filtrate to 50-60ml, adding silica gel, rotary steaming, stirring, purifying by column chromatography, eluting with mixed solution of ethyl acetate and petroleum ether at volume ratio of 1:20 to obtain white powdered solid Z₁(0.2352 g, yield: 90.11%);

(2) synthesis of WP 5: to 250ml of 1, 2-dichloroethane were added 1.155g (5 mmol) of intermediate Z₁2.763g (20 mmol) of 1, 4-dimethoxybenzene and 0.7503g (25 mmol) of paraformaldehyde, stirring for 30 minutes at room temperature, dropwise adding boron trifluoride diethyl etherate with the concentration of 47.0-47.7%, adding water to quench the reaction after 20 minutes of reaction, washing with water for 3-4 times, collecting the lower liquid layer, adding anhydrous sodium sulfate to remove excess water, adding silica gel, performing rotary evaporation to stir the sample, purifying the product by column chromatography, and eluting with a mixed solution of ethyl acetate and petroleum ether at the volume ratio of 1:20 to obtain white powdery solid WP5 (2.4375 g, yield: 55.97%);

(3) synthesis of FA: 0.9307g (5 mmol) of 4, 4-biphenol and 7.009g (50 mmol) of hexamethylenetetramine are added into 70ml of trifluoroacetic acid, the mixture is stirred for 72 hours at 130-135 ℃, the mixture is treated with HCl (4M) at normal temperature, the mixture is fully stirred and then is filtered by suction, and dark yellow solid powder FA (0.6807 g, the yield is 45.68 percent) is obtained;

(4) synthesis of FAN: 0.5961 g (2 mmol) of FA and 0.8g (12 mmol) of hydrazine hydrate are added into 70ml of ethanol, the mixture is heated and refluxed for 12 hours at 85-90 ℃, concentrated, filtered by suction and rinsed by ethanol, and light yellow green solid powder (0.567 g, yield: 80%) is obtained;

(5) synthesis of FAP 5: weighing the compounds FAN 0.5961 g (1 mol), 2.5237 g (3.5 mol) WP5, KI (0.3320 g, 2 mmol) and K₂CO₃(0.2762 g, 2 mmol) was added to 70ml of acetonitrile solvent, and after completely dissolving by stirring, the mixture was reacted at 95 ℃ for 72 hours, and then the reaction was carried outAfter completion of the reaction, the mixture was concentrated by cooling, filtered with suction, and rinsed with acetonitrile to obtain FAP5 (1.3941 g, yield: 72%) as a yellow solid powder.

2. Synthesis of guest pyridinium BN

1, 10-dibromodecane (1.500 g, 5 mmol), 4, 4-bipyridine (2.186 g, 14 mmol) were weighed out and added to 50ml acetonitrile, refluxed at 90 ℃ for 20h, filtered with suction after the reaction was completed, and recrystallized from acetonitrile to obtain light green solid BN (1.946g, 86%).

3. Synthesis of supramolecular polymer FAP5-BN

The host molecule FAP5 (0.0048 g, 2.5X 10)^-6mol) and guest molecule BN (0.003 g, 2.5X 10)^- ⁶mol) dissolved in 25mL of DMSO-H under heating₂In O system (DMSO and H)₂The volume ratio of O is 3: 7) to obtain the supermolecular polymer FAP 5-BN.

Example two identification of Hg by the supramolecular polymer FAP5-BN²⁺

Transferring 2 ml of DMSO-H of FAP5-BN as supramolecular polymer₂O solution (C)_Q=1×10^-5M, DMSO and H₂Volume ratio of O3: 7) in a series of colorimetric tubes, Mg²⁺,Ca²⁺, Cr³⁺,Hg²⁺,Co²⁺,Ni²⁺,Cu²⁺,Zn²⁺,Pb²⁺,Cd²⁺, Fe³⁺,Ag⁺,Eu³⁺H of (A) to (B)₂O solution (C = 0.1M), if the fluorescence of supramolecular polymer FAP5-BN is clearly turned on, indicating that Hg was added²⁺If the fluorescence of the supramolecular polymer FAP5-BN does not change obviously, the situation that Hg is not added is indicated²⁺。

Claims

1. A supermolecular polymer is prepared by double-column reaction of main body [5]]Aromatic hydrocarbon and guest pyridinium are heated and dissolved in DMSO-H according to the molar ratio of 1:2₂In the O system, a supramolecular polymer is obtained by self-assembly of a host and an object;

the structural formula of the FAP5 is as follows:

the guest pyridinium salt has the following structural formula:

。

2. the supramolecular polymer as claimed in claim 1, wherein: DMSO-H₂In the O system, DMSO and H₂The volume ratio of O is 1: 2-1: 2.5.

3. The supramolecular polymer in claim 1, for detecting Hg in aqueous solutions²⁺The use of (1).

4. The supramolecular polymer in claim 3, being capable of detecting Hg in an aqueous solution²⁺The application of (2), which is characterized in that: DMSO-H in supramolecular polymers₂In the O system, Mg is added respectively²⁺,Ca²⁺,Cr³⁺,Hg²⁺,Co²⁺,Ni²⁺,Cu²⁺,Zn²⁺,Pb²⁺, Cd² ⁺,Fe³⁺,Ag⁺,Eu³⁺H of (A) to (B)₂O solution of Hg only²⁺The addition of (a) can cause the fluorescence of the supramolecular polymer to be turned on, while the addition of other cations cannot cause a change in the fluorescence of the supramolecular polymer.