CN112175195A - Supramolecular polymer gel, preparation thereof and application of supramolecular polymer gel in fluorescent recognition of iron ions and fluorine ions - Google Patents

Abstract

The invention discloses a supramolecular polymer gel, which is a coumarin functionalized column [5] serving as a main gelator]Arene derivative and guest gelator bromine functionalized column [5]The aromatic hydrocarbon derivative is obtained by self-assembly complexing in cyclohexanol according to the molar ratio of 2: 1. The supermolecule polymer gel shows light blue fluorescence in cyclohexanol, and Zn is added into the supermolecule gel²⁺，Cd²⁺，Hg²⁺，Co²⁺，Ni²⁺，Al³⁺，Fe³⁺，Cu²⁺，Pb²⁺，Mg²⁺，Ba²⁺，Cr³⁺And Ag⁺Of an aqueous solution of (1), only Fe³⁺Is capable of quenching the fluorescence of the gel, and Fe³⁺Generation of supramolecular metalloorganogels PCDP by interaction with supramolecular polymer gels-Fe. Respectively adding F into the supermolecular metal organogel PCDP-Fe^‑,Cl^‑,Br^‑,I^‑,AcO^‑,SO₄ ^2‑,ClO₄ ^‑,CN^‑,SCN^‑And N₃ ^‑Aqueous solution of (2) only F^‑Can enable the fluorescence of the supermolecular metal organogel PCDP-Fe to be opened again. Therefore, the supramolecular polymer gel can be used for identifying Fe by fluorescence³⁺、F^‑. The ultrasensitive fluorescence recognition performance has important application value in the field of ion recognition.

Description

Supramolecular polymer gel, preparation thereof and application of supramolecular polymer gel in fluorescent recognition of iron ions and fluorine ions

Technical Field

The invention relates to a supramolecular polymer gel, in particular to a gel based on a column [5]]Supramolecular polymer gel of aromatic hydrocarbon derivatives, mainly for the continuous recognition of Fe³⁺And F^-Belongs to the field of chemical synthesis and ion detection。

Background

Ions play a very important role in many fields such as chemical, environmental and biological systems. Therefore, it is crucial for the ultra-sensitive detection of certain specific ions in different environments. Iron is widely distributed in nature, is one of the most abundant elements in the earth crust, and has been widely used for steel making, cast iron and forged iron. Iron and its compounds are also used as magnets, dyes (inks, blueprints, carmine pigments) and abrasives (rouge powder). However, the mishandling of iron in industrial-grade refining processes can result in large amounts of iron inorganic salt waste in the form of ions. In addition, iron ion (Fe)³⁺) As essential trace elements in plants and animals, the trace elements play important roles in cell metabolism, enzyme catalysis, oxygen transport in hemoglobin and the like, and play an auxiliary role in enzyme-based reactions. Iron overload, acute or chronic poisoning can be caused by a single large dose of iron or a large amount of iron in a short period of time. Abnormal levels of iron are indicative of diseases such as anemia, hemochromatosis, parkinson's disease, arthritis, diabetes, hepatitis, and cancer. Thus, for environmental aspects or iron fortified food aspects, Fe³⁺And is also one of the important sources of environmental pollution.

Fluorine is widely present in natural water and is a trace element. All tissues of human body contain fluorine, but the fluorine is mainly accumulated in teeth and bone tendons, and a proper amount of fluorine has the function of preventing dental caries. The level of serum fluorine in human body is an objective index directly reflecting the content of fluorine taken in the environment outside the body, and the increase of serum fluorine indicates the increase of fluorine load in the body. Excessive fluorine can cause acute or chronic fluorosis, causing harm to the human body. The fluorine bone injury is chronic accumulative metabolic lesion caused by overhigh fluorine load of a body; excess fluorine can cause memory impairment, mood swings, headaches, and ataxia in non-osseous systems, particularly the central nervous system. The local fluorosis has wide distribution range in China and various types of disease areas, is a local disease seriously harming the health of vast rural residents, and is particularly important for the detection of the drinking water industry.

Various ion detection methods have been developed. The traditional detection methods such as voltammetry, spectroscopic spectroscopy, atomic absorption spectroscopy, inductively coupled plasma mass spectrometry and the like require precise equipment and complicated sample preparation processes. In contrast, the fluorescence colorimetric method has been developed as a main detection means for ion identification due to its advantages of simple operation, rapidness, high sensitivity, and the like. However, in real life, various ions which are beneficial or harmful to human bodies mostly exist in the water phase, most of the reported methods for detecting the ions are carried out in solution, and the detection of the ions also needs a professional instrument, so that unnecessary burden is added to the detection in a specific implementation process.

The pillared aromatic hydrocarbon derivatives are important material carriers and are rapidly developed in the aspects of supramolecular sensors, stimulus reaction self-assembly, liquid crystals, drug delivery systems, supramolecular polymers, transmembrane channels, green catalysis and the like.

Disclosure of Invention

The invention aims to provide a column [5] arene derivative-based supramolecular polymer gel and a preparation method thereof;

another object of the present invention is to provide the supramolecular polymer gel for recognizing Fe in continuous fluorescence³⁺And F^-The use of (1).

Mono-and supramolecular polymer gels

The supramolecular polymer gel is obtained by self-assembling and complexing a coumarin functionalized column [5] arene derivative (PC) of a main gelator and a bromine functionalized column [5] arene Derivative (DP) of a guest gelator in cyclohexanol according to a molar ratio of 2:1, and is marked as PCDP. The structure of PCDP is as follows:

。

the structural formula of the coumarin functionalized column [5] arene derivative (PC) is as follows:

。

preparation of coumarin functionalized column [5] arene derivative (PC): the preparation method of the coumarin functionalized column [5] arene derivative comprises the following steps: using dichloromethane as a solvent, using triethylamine as an acid-binding agent, reacting the column [5] arene derivative (a) and coumarin 3-formyl chloride (b) at room temperature for 3-5 h according to a molar ratio of 1: 1-1: 1.5, and adding methanol for recrystallization to obtain a yellow solid, namely coumarin functionalized column [5] arene derivative PC; the adding amount of triethylamine is 1-3% of the molar amount of the column [5] arene derivative. The PC synthetic route is as follows:

。

fig. 1, 2 and 3 are a hydrogen spectrum, a carbon spectrum and a mass spectrum of the synthesized coumarin functionalized column [5] arene derivative (PC), respectively. The chemical shift values of PC are 10.94 (doublet, 1H), 9.24 (doublet, 1H), 8.84 (doublet, 1H), 7.72-7.67 (multiplet, 2H), 7.44-7.38 (multiplet, 2H), 6.77-6.71 (multiplet, 2H), 3.87-3.85 (multiplet, 2H), 3.77-3.73 (multiplet, 10H), 3.65-3.59 (multiplet, 27H), 3.34 (singlet, 2H), 2.71-2.68 (multiplet, 2H), 1.89-1.83 (multiplet, 4H) as determined by a hydrogen spectrogram. According to the carbon spectrum, the chemical shift value of PC is as follows: 165.54, 160.59, 158.29, 154.52, 150.82, 150.79, 150.76, 150.73, 149.90, 148.97, 134.61, 129.92, 128.34, 128.26, 128.19, 128.12, 125.43, 118.30, 116.92, 116.81, 116.73, 115.02, 114.19, 114.09, 113.97, 67.77, 55.85, 55.83, 55.79, 55.77, 55.74, 55.70, 40.91, 29.68, 29.59, 28.77, 25.89. From the mass spectrum, the calculated relative molecular weight of PC was 1091.3976, and the experimental value was 1091.3959. Thus, it can be said that the structure of the PC is correct.

The structural formula of the bromine-functionalized column [5] arene Derivative (DP) is as follows:

。

synthesis of bromo-functionalized column [5] arene derivative DP: see references Y. -M. Zhang, W. Zhu, X. -J. Huang, W. -J. Qu, J. -X. He, H. Fang, H. Yao, T. -B. Wei and Q. Lin, ACS Sustainable chem. Eng. 2018, 6, 16597-.

Preparation of PCDP: fully dissolving coumarin functionalized column [5] arene and bromine functionalized column [5] arene into cyclohexanol under heating, and cooling to room temperature (< 60 ℃) to form stable supramolecular polymer gel. The content of the coumarin functionalized column [5] arene derivative and the bromine functionalized column [5] arene derivative in cyclohexanol is 0.1-0.2 g/mL.

FIGS. 4 and 5 are partial nuclear magnetic titrations of PC (0.01M) solution with different equivalent DP. FIG. 4 (a) PC (0.01M); (b) PC +1.0equiv. DP; (c) DP (0.01M), from which H is evident in the host PC molecule_a、H_b、H_c、H_nProton peak moving to low field, H in object DP molecule₄The proton peak moves to the high field, indicating penetration of the alkyl chain portion of the DP molecule into the cavity of the cycloparaffin in the PC molecule. FIG. 5 (a) PC (0.01M); (b) PC +0.5equiv. DP; (c) PC +1.0equiv. DP; (d) PC +1.5equiv. DP graph showing that as the concentration of DP in the host PC molecules increases, H in the host PC molecules_e、H_f、H_dThe proton peak moves to the low field while H_i、H_j、H_k、H_lThe proton peak moves to a high field, which shows that pi-pi action and hydrogen bond action exist between coumarin groups and between hydrazide groups in PC molecules respectively. In addition, the proton-related peak shift of the column aromatic hydrocarbon groups in the PC molecule and the DP molecule both to the low field indicates the existence of the π - π interaction between the column aromatic hydrocarbon groups in the PC molecule and the DP molecule.

FIG. 6 shows the two-dimensional NMR spectrum of a PC (0.01M) solution with DP added. PC molecule H_a、H_cProton peak and H of DP molecule₃The A point correlation peak appeared from the proton peak, which proves that the alkyl chain part of the PC molecule enters into the column arene cavity of the PC molecule. PC molecule H_a、H_cProton Peak and DP molecule H₃The correlation point B of the proton peak confirms the existence of pi-pi stacking of the pillared arene units in the DP and PC molecules. Meanwhile, PC intermolecular H_i、H_lAnd H_k、H_mThe point C, D of the correlation between the two groups indicates that pi-pi stacking exists between the coumarin groups.

Ultra-sensitive fluorescence detection of Fe by using bi-and supramolecular polymer gel PCDP³⁺And F^-Application of

1. Fluorescence properties of supramolecular polymer gels PCDP

The fluorescence property research of the supramolecular polymer gel PCDP shows that the gel PCDP has the fluorescence emission property in cyclohexanol: PCDP fluoresces yellowish (emission wavelength 528 nm) when the excitation wavelength is 365 nm.

2. Supramolecular polymer gel PCDP vs. Fe³⁺Fluorescence detection Performance of

Cyclohexanol solution (concentration 9X 10) in supramolecular polymer gel PCDP^-3mol/L), 0.5 equivalent (relative to PC) of Zn is added²⁺，Cd²⁺，Hg²⁺，Co²⁺，Ni²⁺，Al³⁺，Fe³⁺，Cu²⁺，Pb²⁺，Mg²⁺，Ba²⁺，Cr³⁺And Ag⁺The fluorescence and color change of the solution were observed in the aqueous solution (C =0.1 mol/L).

FIGS. 7 and 8 are the fluorescence full scan (. lamda.) of the supramolecular polymer gel PCDP for cations, respectively_ex=360 nm) and p-Fe^{3 +}Fluorescence titration graph of (a). As can be seen from FIG. 7, only Fe³⁺Can quench the fluorescence of PCDP, and the addition of other ion solution can not change the fluorescence of DMSO solution of PCDP. As can be seen from FIG. 8, only 0.009 times equivalent of Fe is required³⁺The fluorescence of PCDP was completely quenched. Illustrating the supramolecular polymer gel PCDP vs Fe³⁺The aqueous solution has the fluorescence specificity selective recognition performance.

FIG. 9 is PCDP versus Fe based on a fit of fluorescence titration (FIG. 8) data³⁺The lowest detection limit of fluorescence. As can be seen from FIG. 9, PCDP vs Fe³⁺The lowest detection limit of fluorescence reaches 4.17 multiplied by 10^-10And M. Description of PCDP vs Fe³⁺The fluorescent detection of the fluorescent probe achieves ultra-sensitive identification.

3. Supermolecular metal organogel PCDP-Fe pair F^-Fluorescence detection Performance of

Cyclohexanol solution (concentration 9X 10) in supramolecular polymer gel PCDP^-3mol/L), 0.5 equivalent (relative to PC) of Fe is added³⁺，Fe³⁺Is capable of quenching the fluorescence of the supramolecular polymer gel, and Fe³⁺Generating supermolecule metal organogel PCDP-Fe by the action of supermolecule polymer gel; separately, 0.5 equivalent (relative to PC) of F was added to the supramolecular metalorganic gel PCDP-Fe^-, Cl^-, Br^-, I^-, AcO^-, SO₄ ^2-, ClO₄ ^-, CN^-, SCN^-And N₃ ^-The fluorescence and color change of the solution were observed in the aqueous solution (C =0.1 mol/L).

FIGS. 10 and 11 show fluorescence full scans (λ) of anions by PCDP-Fe, respectively_ex=360 nm) and p-F^-Fluorescence titration graph of (a). As can be seen from FIG. 10, only F^-The fluorescence of PCDP-Fe can be turned on, and the addition of other anion solution can not change the fluorescence of PCDP-Fe. As can be seen from FIG. 11, only 0.018 times equivalent of F is required^-The fluorescence of PCDP-Fe was completely turned on. Illustrating the supramolecular polymer gel PCDP-Fe to F^-The aqueous solution has the fluorescence specificity selective recognition performance.

FIG. 12 is a PCDP versus F based on a fit of fluorescence titration (FIG. 11) data^-The lowest detection limit of fluorescence. As can be seen from FIG. 12, PCDP vs F^-The lowest detection limit of fluorescence reaches 6.77 multiplied by 10^-10And M. Description of PCDP vs F^-The fluorescent detection of the fluorescent probe achieves ultra-sensitive identification.

Fourth, recognition mechanism analysis

FIG. 13 shows fluorescent recognition of Fe by PCDP of supramolecular polymer gel³⁺And F^-An infrared spectrum of (1). The infrared experiment shows that Fe is added into the supermolecular polymer gel PCDP³⁺Rear, 3419 cm^-1the-NH peak at (C) was shifted to 3450 cm^-1Due to F^-With Fe³⁺Has stronger coordination ability, and F is added^-Then, the sample was moved to 3450 cm^-1. Illustrating Fe³⁺Coordinated to the hydrogen atom of the hydrazide bond-NH in PCDPHydrogen bonding to cause intramolecular charge transfer leading to fluorescence quenching; and F is added^-With Fe³⁺The co-coordination of (a) causes the fluorescence to turn on.

FIG. 14 shows the addition of Fe to the PCDP of the supramolecular polymer gel³⁺And F^-Transmission electron micrograph (D). As can be seen from the figure, the prepared gel PCDP has a spherical shape, and Fe is added³⁺Then the mixture is changed into a cross-linked dumbbell-shaped appearance, and F is added again^-Then the shape of the dumbbell with smaller particles is changed. This result also demonstrates PCDP and F^-、Fe³⁺And (5) conclusion of coordination.

Drawings

FIG. 1 is a hydrogen spectrum of PC.

FIG. 2 is a carbon spectrum of PC.

FIG. 3 is a mass spectrum of PC.

FIG. 4 is a partial nuclear magnetic titration plot of PC and DP.

FIG. 5 is a partial concentration NMR chart of PC and DP.

FIG. 6 is a two-dimensional NMR spectrum of PC and DP.

FIG. 7 shows a fluorescence full scan of PCDP versus cations.

FIG. 8 is PCDP vs Fe³⁺Fluorescence titration graph of (a).

FIG. 9 shows PCDP vs Fe³⁺The lowest detection limit of fluorescence.

FIG. 10 shows a fluorescence full scan of PCDP-Fe for anions.

FIG. 11 shows a pair of PCDP-Fe pairs F^-Fluorescence titration graph of (a).

FIG. 12 shows PCDP-Fe vs. F^-The lowest detection limit of fluorescence.

FIG. 13 shows PCDP fluorescence recognition of Fe³⁺And F^-An infrared spectrum of (1).

FIG. 14 shows the addition of Fe to PCDP³⁺And F^-Transmission electron micrograph (D).

Detailed Description

The preparation of the supramolecular polymer gel and the fluorescent recognition of Fe according to the invention are described below by way of specific examples³⁺、F^-The application of (a) is further illustrated.

EXAMPLE one preparation of supramolecular Polymer gel PCDP

1. Preparation of coumarin functionalized column [5] arene derivative PC

(1) Adding 2g of coumarin-3 carboxylic acid and two drops of DMF (dimethyl formamide) into 30mL of thionyl chloride, refluxing for 4-5 h, and then carrying out reduced pressure distillation to obtain white solid coumarin 3-formyl chloride.

(2) The synthesis of column [5] arene derivatives is described in references w. -b. Zhu, t. -b. Wei, y. -q. Fan, w. -j. Qu, w. Zhu, x. -q. Ma, h. Yao, y. -m. Zhang, q. Lin, Dyes and pigm., 2020, 174, 108073.

(3) Adding the column [5] arene derivative (0.45 g, 0.5 mmol) and coumarin 3-formyl chloride (0.104 g, 0.5 mmol) into 30mL of dichloromethane, then adding 1mL of triethylamine, reacting for 4h at room temperature, adding methanol, and recrystallizing to obtain a yellow solid, namely coumarin functionalized column [5] arene derivative PC (0.38 g, yield 72%).

2. Preparation of bromine functionalized column [5] arene derivative DP

1, 4-bis (4-bromohexyl) benzene (1.9 g, 5.0 mmol), 1, 4-dimethoxybenzene (2.76 g, 20.0 mmol) and paraformaldehyde (0.75 g, 25.0 mmol) were dissolved in dichloroethane with stirring, and boron trifluoride ether (6.75 mL, 25 mmol) was added and reacted at 30 ℃ for 4 hours. The resulting mixture was concentrated and dissolved in dichloromethane, washed twice with water, and the organic phase was dried over anhydrous sodium sulfate and subjected to column chromatography (petroleum ether: ethyl acetate =20:1, V: V) to obtain compound DP (2.02g, yield 38.66%) as a white solid.

3. Preparation of supramolecular polymer gel PCDP

PC (0.02 g, 0.02 mmol) and DP (0.01 g, 0.01 mmol) were weighed and added to cyclohexanol (0.2 mL), heated to dissolve and then cooled to room temperature (< 60 ℃ C.) to obtain supramolecular polymer gel PCDP.

Example two Single Selective fluorescent recognition of Fe by supramolecular Polymer gel³⁺

Adding 0.5 equivalent of Zn into cyclohexanol solution of supermolecular polymer gel PCDP²⁺，Cd²⁺，Hg²⁺，Co²⁺，Ni²⁺，Al³⁺，Fe³⁺，Cu²⁺，Pb²⁺，Mg²⁺，Ba²⁺，Cr³⁺And Ag⁺If the fluorescence of the gel PCDP is quenched, it is indicated that Fe is added (C =0.1mol/L)³⁺If the fluorescence of the gel PCDP is not changed, it indicates that the added Fe is not Fe³⁺。

EXAMPLE III supramolecular metallo-organogels PCDP-Fe vs F^-Fluorescent identification of

Adding 0.5 times of equivalent of Fe into cyclohexanol solution of supermolecular polymer gel³⁺，Fe³⁺Is capable of quenching the fluorescence of the supramolecular polymer gel, and Fe³⁺Generating supermolecule metal organogel PCDP-Fe by the action of supermolecule polymer gel; adding 0.5 times of equivalent F into the supermolecule metal organogel PCDP-Fe respectively^-, Cl^-, Br^-, I^-, AcO^-, SO₄ ^2-, ClO₄ ^-, CN^-, SCN^-And N₃ ^-If the fluorescence of the supramolecular metalorganic gel PCDP-Fe is turned back on, indicating that F is added (C =0.1mol/L)^-If the fluorescence of the supramolecular metal organogel PCDP-Fe is not changed, the result shows that F is not added^-。

Claims (9)

1. A supramolecular polymer gel is prepared by self-assembling and complexing a coumarin functionalized column [5] arene derivative of a main gelator and a bromine functionalized column [5] arene derivative of a guest gelator in cyclohexanol according to the molar ratio of 2: 1;

the structural formula of the coumarin functionalized column [5] arene derivative is as follows:

the structural formula of the bromine functionalized column [5] arene derivative is as follows:

。

2. the supramolecular polymer gel as claimed in claim 1, wherein: the content of the coumarin functionalized column [5] arene derivative and the bromine functionalized column [5] arene derivative in cyclohexanol is 0.1-0.2 g/mL.

3. A process for the preparation of supramolecular polymer gels as claimed in claims 1-2, characterized in that: fully dissolving coumarin functionalized column [5] arene and bromine functionalized column [5] arene into cyclohexanol under heating, and cooling to room temperature to form stable supramolecular polymer gel.

4. The supramolecular polymer gel as claimed in claim 1, wherein: the preparation method of the coumarin functionalized column [5] arene derivative comprises the following steps: using dichloromethane as a solvent, using triethylamine as an acid-binding agent, reacting the column [5] arene derivative and coumarin 3-formyl chloride at room temperature for 3-5 hours according to a molar ratio of 1: 1-1: 1.5, and adding methanol for recrystallization to obtain a yellow solid, namely the coumarin functionalized column [5] arene derivative; the adding amount of triethylamine is 1-3% of the molar amount of the column [5] arene derivative.

5. The supramolecular polymer gel as claimed in claim 4, wherein: the structural formula of the column [5] arene derivative is as follows:

。

6. the supramolecular polymer gel as claimed in claim 1, recognizing Fe at single selective fluorescence³⁺The use of (1).

7. The supramolecular polymer gel as claimed in claim 6, recognizing Fe at single selective fluorescence³⁺The application of (2), which is characterized in that: respectively adding Zn into cyclohexanol solution of supermolecular polymer gel²⁺，Cd²⁺，Hg²⁺，Co²⁺，Ni²⁺，Al³⁺，Fe³⁺，Cu^{2 +}，Pb²⁺，Mg²⁺，Ba²⁺，Cr³⁺And Ag⁺Of an aqueous solution of (1), only Fe³⁺Is capable of quenching the fluorescence of the supramolecular polymer gel.

8. The supramolecular polymer gel as claimed in claim 1, recognizing Fe in continuous fluorescence³⁺、F^-The use of (1).

9. The supramolecular polymer gel of claim 8, recognizing Fe in continuous fluorescence³⁺、F^-The application of (2), which is characterized in that: respectively adding Zn into cyclohexanol solution of supermolecular polymer gel²⁺，Cd²⁺，Hg²⁺，Co²⁺，Ni²⁺，Al³⁺，Fe³⁺，Cu^{2 +}，Pb²⁺，Mg²⁺，Ba²⁺，Cr³⁺And Ag⁺Of an aqueous solution of (1), only Fe³⁺Is capable of quenching the fluorescence of the supramolecular polymer gel, and Fe³⁺Reacting with the supermolecular polymer gel to generate supermolecular metal organogel; adding F into the supermolecule metal organogel^-, Cl^-, Br^-, I^-, AcO^-, SO₄ ^2-, ClO₄ ^-, CN^-, SCN^-And N₃ ^-Aqueous solution of (2) only F^-Can cause the fluorescence of the supramolecular metal organogel to reopen.

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