阅读说明：本技术 一类手性席夫碱类聚合物及其制备方法和应用 (Chiral Schiff base polymers and preparation method and application thereof ) 是由 唐本忠 胡蓉蓉 何友玲 秦安军 赵祖金 于 2020-03-02 设计创作，主要内容包括：本发明属于高分子化学和材料学领域,公开了一类具有荧光和手性双重可逆响应的手性席夫碱类聚合物及其制备方法和应用。该手性席夫碱类聚合物的结构式为如下结构中的一种,其制备方法包括以下步骤：通过在在空气条件下,将手性二元胺化合物和2-羟基苯甲醛化合物以及有机溶剂混合,在30-100℃搅拌反应10-30min,当反应液由浑浊逐渐得到透明黄色溶液时停止反应,然后将所得反应产物进行纯化即得手性席夫碱类聚合物。所得手性席夫碱类聚合物对锌离子的检测具有高的选择性,在逐渐加入锌离子和EDTA可实现荧光和手性双重可逆响应,因此可应用于锌离子及EDTA的检测中。<Image he="312" wi="700" file="DDA0002397277620000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The invention belongs to the field of polymer chemistry and material science, and discloses a chiral Schiff base polymer with fluorescence and chiral reversible response, and a preparation method and application thereof. The structural formula of the chiral Schiff base polymer is one of the following structures, and the preparation method comprises the following steps: by reacting a chiral diamine compound with a chiral diamine compound under air conditionsMixing the 2-hydroxybenzaldehyde compound and the organic solvent, stirring and reacting at 30-100 ℃ for 10-30min, stopping the reaction when the reaction solution gradually obtains a transparent yellow solution from turbidity, and then purifying the obtained reaction product to obtain the chiral Schiff base polymer. The obtained chiral Schiff base polymer has high selectivity on the detection of zinc ions, and can realize double reversible responses of fluorescence and chirality when zinc ions and EDTA are gradually added, so that the chiral Schiff base polymer can be applied to the detection of zinc ions and EDTA.)

1. A chiral Schiff base polymer is characterized in that the structural formula is one of the structures shown as the following general formula:

wherein n is an integer between 2 and 40; r₁Is H or alkyl, R₂Is H or alkyl, R₃Is H or alkyl, R₄Is H or alkyl, and Ar is aryl or alkyl-substituted aryl.

2. The chiral schiff base polymer according to claim 1, wherein the structural formula is one of the structures shown below:

wherein n is an integer between 2 and 40.

3. A process for the preparation of chiral schiff base polymers according to claim 1 or 2, characterized by comprising the steps of: under the air condition, mixing a chiral diamine compound, a binary 2-hydroxybenzaldehyde compound and an organic solvent, stirring and reacting at 30-100 ℃ for 10-30min until a transparent yellow solution is obtained, stopping the reaction, and purifying the obtained reaction product to obtain a chiral Schiff base polymer;

wherein the chiral diamine compound is selected from any one of the following structures:

R₁is H or alkyl, R₂Is H or alkyl, R₃Is H or alkyl, R₄Is H or alkyl;

the structure of the binary 2-hydroxybenzaldehyde compound is shown as follows:

wherein Ar is aryl or alkyl substituted aryl.

4. The method of preparing chiral schiff base polymers according to claim 3, wherein:

the organic solvent is at least one of ethanol, dichloromethane, N-dimethylformamide and tetrahydrofuran.

5. The method of preparing chiral schiff base polymers according to claim 3, wherein:

the molar ratio of the chiral diamine compound to the binary 2-hydroxybenzaldehyde compound is 1: 1;

the amount of the reaction solvent is such that 5-20m L of organic solvent is added for every 5.0mmol of chiral diamine compound.

6. The method of preparing chiral schiff base polymers according to claim 3, wherein:

and the purification is to cool the obtained reaction product to room temperature, dissolve the reaction product in an organic solvent, add the reaction product into a settling agent for precipitation, collect the precipitate, and dry the precipitate at room temperature to constant weight to obtain the purified chiral Schiff base polymer.

7. The method of preparing chiral schiff base polymers according to claim 6, wherein:

the organic solvent in the purification process is at least one of ethanol, dichloromethane, N-dimethylformamide and tetrahydrofuran; the settling agent in the purification process is methanol.

8. The chiral schiff base polymer according to claim 1 or 2, which is used in zinc ion detection and ethylenediamine tetraacetic acid detection.

Technical Field

The invention belongs to the fields of polymer chemistry and materials science, and particularly relates to a chiral Schiff base polymer with fluorescence and chiral reversible response, and a preparation method and application thereof.

Background

Chirality is widely found in nature and is also common in the most abundant forms of matter. In recent years, supramolecular chirality has attracted much attention for its application in the fields of chiral recognition, sensing, catalysis, etc. Schiff base structures (salen) containing C ═ N groups can form complexes with most different metal ions. The ligand (salen) and the metal complex thereof have wide application in molecular catalysis, biological activity, drug molecular design, functional materials and the like. Since selective coordination and binding of certain metal ions to polymeric chromophores can greatly affect the optical properties and chiral strength of the materials, it is an ideal candidate material for sensors and molecular machines. Currently reported salen ligand compounds are generally based on small molecules, and most polymer structures do not contain groups with large steric hindrance, so that stable conformations are not easy to obtain, the reports of polymers are few, and the research on chiral performance is less at present. Therefore, the development of a novel chiral salen compound is very potential to be applied to the aspects of sensors and molecular machines. (Molecules 2019,24, 1716.; Dalton Trans.2016,45,3927-

Disclosure of Invention

In order to overcome the defects and shortcomings of the prior art, the invention mainly aims to provide a chiral schiff base polymer with fluorescence and chiral reversible response.

The invention also aims to provide a preparation method of the chiral schiff base polymer with fluorescence and chiral reversible responses. .

The invention further aims to provide application of the chiral Schiff base polymer with fluorescence and chiral reversible response.

The purpose of the invention is realized by the following scheme:

a chiral Schiff base polymer has a structural formula which is one of the structures shown in the following general formula:

wherein n is an integer between 2 and 40; r₁Is H or alkyl, R₂Is H or alkyl, R₃Is H or alkyl, R₄Is H or alkyl, and Ar is aryl or alkyl-substituted aryl.

The structural formula of the chiral schiff base polymer is preferably one of the following structures:

wherein n is an integer between 2 and 40.

The preparation method of the chiral schiff base polymer comprises the following steps: under the air condition, mixing a chiral diamine compound, a binary 2-hydroxybenzaldehyde compound and an organic solvent, stirring and reacting for 10-30min at 30-100 ℃, stopping the reaction when the reaction solution gradually obtains a transparent yellow solution from turbidity, and then purifying the obtained reaction product to obtain the chiral Schiff base polymer.

The chiral diamine compound is selected from any one of the following structures:

wherein R is₁Is H or alkyl, R₂Is H or alkyl, R₃Is H or alkyl, R₄Is H or alkyl.

The structure of the binary 2-hydroxybenzaldehyde compound is shown as follows:

wherein Ar is aryl or alkyl substituted aryl.

The organic solvent is at least one of ethanol, dichloromethane, N-dimethylformamide and tetrahydrofuran, the organic solvent is used for dissolving reactants and is beneficial to the polymerization reaction, on the other hand, the amount of the reaction solvent needs to be limited in consideration of the removal of the solvent after the reaction, and generally, 5-20m L of the organic solvent is correspondingly added to every 5.0mmol of chiral diamine compound.

The molar ratio of the chiral diamine compound to the binary 2-hydroxybenzaldehyde compound is 1: 1.

The purification is to cool the obtained reaction product to room temperature, then dissolve the reaction product in a small amount of organic solvent (at least one of ethanol, dichloromethane, N-dimethylformamide and tetrahydrofuran), then add the reaction product into a large amount of settling agent (methanol) for precipitation, collect the precipitate and dry the precipitate to constant weight at room temperature to obtain the purified chiral Schiff base polymer.

The chiral Schiff base polymer can realize double reversible fluorescence response and chiral response to the detection of zinc ions and Ethylene Diamine Tetraacetic Acid (EDTA), so that the chiral Schiff base polymer can be applied to the detection of zinc ions and the detection of Ethylene Diamine Tetraacetic Acid (EDTA).

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the preparation method is simple, mild in condition, capable of being carried out at room temperature and rapid in reaction.

(2) The product yield of the invention is very high, 85-90%.

(3) The chiral Schiff base polymer prepared by the invention has high selectivity for detecting zinc ions.

(4) The chiral Schiff base polymer prepared by the invention can realize double reversible fluorescence response and chiral response for detecting zinc ions.

Drawings

FIG. 1 is a comparison graph of nuclear magnetic resonance hydrogen spectra in deuterated chloroform of chiral Schiff base polymers prepared in example 1 of the invention and model compounds prepared in example 2.

FIG. 2 is a comparison graph of nuclear magnetic resonance carbon spectra in deuterated chloroform of chiral Schiff base polymers prepared in example 1 of the invention and model compounds prepared in example 2.

Fig. 3 is a graph of the infrared absorption spectra of the chiral schiff base polymer prepared in example 1 and the model compound prepared in example 2 of the present invention.

FIG. 4 is a graph of the absorption spectra of the chiral Schiff base polymer prepared in example 1 and the model compound prepared in example 2 of the present invention.

FIG. 5 is a fluorescence spectrum of the chiral Schiff base polymer prepared in example 1 and the model compound prepared in example 2.

FIG. 6 is a circular dichroism spectrum of the chiral Schiff base polymer prepared in example 1 and the model compound prepared in example 2.

FIG. 7 is a bar graph of fluorescence intensity of chiral Schiff base polymers prepared in example 1 and model compounds prepared in example 2 after different metal ions are added.

Fig. 8 is a graph showing reversible fluorescence response of the chiral schiff base polymer prepared in example 1 of the present invention and the model compound prepared in example 2 after gradual addition of zinc ions and ethylenediaminetetraacetic acid (EDTA), wherein (a) and (B) are graphs showing reversible fluorescence response of the chiral schiff base polymer prepared in example 1 of the present invention after addition of zinc ions and ethylenediaminetetraacetic acid (EDTA); (C) and (D) is a reversible fluorescence response diagram of the chiral Schiff base model compound prepared in example 2 of the invention when zinc ions and Ethylene Diamine Tetraacetic Acid (EDTA) are added.

FIG. 9 is a circular dichroism spectrum diagram of chiral Schiff base polymers RR-P1 and SS-P1 prepared in example 1 of the present invention after addition of different metal ions, wherein (A) represents RR-P1, and (B) represents SS-P1.

FIG. 10 is a circular dichroism spectrum of chiral Schiff base model compounds RR-1 and SS-1 prepared in example 2 of the present invention, after addition of different metal ions, wherein (A) represents RR-1 and (B) represents SS-1.

FIG. 11 shows that zinc metal ions (0 to 60eq. Zn) are gradually added to SS-P1 and SS-1²⁺) And EDTA (0-60eq. EDTA), wherein (A) is the SS-chiral Schiff base polymer prepared in example 1 of the present invention, 0-60eq. Zn is gradually added dropwise²⁺And reversible uv absorption spectra of EDTA; (B) for the SS-chiral Schiff base polymer prepared in the embodiment 1 of the invention, 1 to 60eq.Zn is gradually added dropwise²⁺And EDTA reversible circular dichroism spectra; (C) gradually dripping 1-60eq.Zn for the SS-chiral Schiff base model compound prepared in the embodiment 2 of the invention²⁺And reversible uv absorption spectra of EDTA; (D) gradually dripping 1-60eq.Zn for the SS-chiral Schiff base model compound prepared in the embodiment 2 of the invention²⁺And a reversible circular dichroism spectrum of EDTA;

FIG. 12 is a chiral fluorescence spectrum of the chiral Schiff base polymer prepared in example 1 of the present invention.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the embodiments of the present invention are not limited thereto.