Preparation and application of colorimetric probe for identifying diethyl ether and hydrogen sulfate radical in water

Abstract

The invention discloses preparation and application of a probe micromolecule capable of being used for visual rapid detection of diethyl ether molecules and hydrogen sulfate ions in pure water. According to the probe molecule, phenol red is used as a core skeleton, and two types of indicator type probe molecules (I and II) are respectively constructed through a Darff reaction, imine condensation and a reductive amination reaction. The two types of probe molecules can generate rapid color change response to trace diethyl ether molecules and hydrogen sulfate radicals in pure water, have no color change response to other organic molecules and anions, and have extremely high selectivity. Wherein the probe molecule can still selectively recognize ppm-level HSO4 <-> ions in water in the presence of interfering ions such as Cl <->, Br <->, I <->, NO3 <->, SO4 < 2->, PF6 <->, ClO4 <-> and OH <->, and the binding constant is up to tens of thousands of M <-1 >. The water-soluble probe molecule disclosed by the invention has the advantages of simple design, quick response, simple synthesis, low cost and the like, and is expected to play a role in the fields of water environment detection, analysis sensing and the like.

Description

Technical Field

[0001] The present invention belongs to the field of analytical chemistry, and particularly relates to the rapid identification and sensing of anions (hydrogen sulfate) and organic small molecules (ethyl ether) in pure water. Background Art

[0002] Water pollution has now become a global environmental problem. The development of human civilization and natural environmental disasters have caused serious environmental pollution, especially water pollution. According to incomplete statistics, about 2 million tons of industrial sewage and domestic waste are discharged into water every day in the world, causing large-scale water body pollution, which seriously threatens the health of organisms on the earth. About 14,000 people die every day in the world due to water pollution problems. The pollutants in water mainly include organic pollutants, inorganic pollutants, biological pollutants, etc. Among them, organic pollutants and some inorganic ionic pollutants (including metal cations and anions) are two types of widely existing pollutants. These substances can pose a great threat to aquatic organisms and human health even at very low concentrations in water. Moreover, due to the polarity and water solubility of such pollutants, they are neither easily removed by traditional water treatment methods nor easily monitored by simple detection equipment. Therefore, it is of great significance to develop new and simple water-soluble sensing materials for the identification of pollutants in water.

[0003] Colorimetric sensing is a type of detection technology with simple preparation, low cost, and rapid response. It has been widely used in the fields of environmental monitoring, clinical diagnosis, public safety, etc. Currently, most of the colorimetric sensing materials for detecting organic pollutants in water are organic-inorganic framework materials, organic polymers, pure carbon materials, or inorganic nanoparticles with complex structures. There are relatively few simple-structured organic small molecule sensing materials. On the one hand, this is because it is difficult for organic small molecules to have recognition sites capable of binding organic pollutant molecules. On the other hand, because most organic molecules are insoluble in water, they do not have the ability of colorimetric sensing. Therefore, it is of great significance and also extremely challenging to develop organic small molecule sensors with sensitive response, good water solubility, low price, and simple preparation for the detection of organic pollutants in the aqueous phase.

[0004] Among them, colorimetric sensors for detecting trace ethyl ether in the aqueous phase are relatively rare. As is well known, ethyl ether is a typical volatile substance. Continuous exposure to ethyl ether may lead to coma or death. The research on ethyl ether sensors in the atmosphere is relatively extensive, and there are also many ethyl ether vapor sensors on the market. However, the research on the sensing of ethyl ether in water is insufficient, and there are few colorimetric ethyl ether sensors for the detection of ethyl ether in the aqueous phase. Developing a water-phase colorimetric ethyl ether sensor has important research value. In addition, the detection of hydrogen sulfate HSO4 - in the aqueous phase also has important significance. Hydrogen sulfate ions play an important role in life activities and environmental science: (1) HSO4 -Abundant in human cells, in human plasma, the content of HSO4 - ranks fourth, which is a component required for the growth and development of somatic cells. Many important biological processes, including biosynthesis and detoxification, are achieved by sulfating exogenous and endogenous substances. (2) HSO4 - often coexists with other oxidizing ions in nuclear waste, having a very adverse impact on the vitrification process in radioactive waste remediation. It will be converted into toxic SO4 2- in an environment with a higher pH value, which will stimulate human skin and eyes and even cause respiratory paralysis after entering the environment. In addition, many fertilizers contain HSO4 - , which will pollute arable land; coal contains HSO4 - , and sometimes it will cause power outages in coal-fired power plants. (3) NaHSO4 is a very important catalyst, especially quite effective for catalyzing condensation and dehydration reactions, and has received wide attention. Therefore, the detection of HSO4 - is very important, but it will cause harm to the human body after entering the environment. Therefore, it is of great significance to develop a colorimetric probe molecule with high selectivity and high sensitivity to recognize hydrogen sulfate ions in aqueous phase. Summary of the Invention

[0005] The purpose of the present invention is to construct a colorimetric organic small molecule sensor with a simple structure, sensitive sensing, simple preparation, and low price, which is used for high-resolution sensing detection of ether molecules and hydrogen sulfate ions in aqueous phase, and realizes multiple uses of one sensor.

[0006] In order to achieve the visual and rapid detection of ether and hydrogen sulfate ions in pure water, this patent provides a preparation method of a small molecule probe with simple preparation, low cost, rapid response, and high selectivity: this probe uses the phenol red structure as the mother nucleus, and through simple functional group modification, a molecule with a color change response to ether and hydrogen sulfate ions is obtained. Its molecular structures I and II are characterized as shown in Formula 1:

[0007]

[0008] In the structural formula, R-(NH2) n is an aliphatic or aromatic primary amine compound, the number of amino groups n≧1, and R-(NH2) n can be but is not limited to the following structures:

[0009]

[0010] The preparation and application of a colorimetric probe for recognizing ether and hydrogen sulfate in water include the following steps:

[0011] Step 1, Preparation of probe molecule I: Weigh an appropriate amount of phenol red, hexamethylenetetramine which is 15 times the amount of phenol red, and an appropriate amount of trifluoroacetic acid, and reflux and react overnight at 100 °C under a nitrogen atmosphere. After the reaction, add 3 mol / L hydrochloric acid aqueous solution to the above mixture, hydrolyze at 100 °C for 1.5 h, then cool to room temperature, filter by suction, extract several times with dichloromethane, dry with anhydrous sodium sulfate, rotary evaporate and purify to obtain probe molecule I.

[0012] Step 2, Preparation of probe molecule II: Weigh 1 mmol of molecule I and n mmol (n is the number of primary amine functional groups) of primary amine compound R-(NH2) n Dissolve in an appropriate amount of organic solvent, and the organic solvents include methanol, ethanol, acetonitrile, N,N-dimethylformamide, dichloromethane, tetrahydrofuran, acetonitrile, etc. The above mixture is refluxed and reacted overnight, and then the imine condensation product a is obtained by filtration or rotary evaporation. The imine condensation product a (1 equivalent) is dissolved in ethanol, and 10 equivalents of sodium borohydride methanol solution is added dropwise in batches and stirred overnight at the reflux temperature. After the reaction, the solution is rotary evaporated and deionized water is added, and stirring is continued at room temperature for 1 h. Then, according to the water solubility of the product, the final product probe molecule II is obtained by filtration or extraction with dichloromethane solution.

[0013] The chemical equation of the above preparation method is specifically as Figure 1 shown.

[0014] Furthermore, the core skeleton structures of the probe molecules I and II are phenol red.

[0015] Furthermore, the structures of the probe molecules I and II are aldehyde group substitution or aminomethyl substitution at the ortho-position of the phenolic group of the phenol red skeleton.

[0016] Furthermore, R-(NH2) in the structure of the probe molecule II n can be any aliphatic or aromatic primary amine compound that can undergo imine condensation reaction with I, and the number of amino groups n ≥ 1.

[0017] Furthermore, the probe molecules I and II can selectively recognize diethyl ether molecules from organic molecules in water, and have no recognition effect on other organic molecules in water. The other organic molecules include methanol, ethanol, dimethyl sulfoxide, N,N-dimethylformamide, tetrahydrofuran, benzene, toluene, cyclohexane, dichloromethane, acetonitrile, acetone, petroleum ether, and 1,4-dioxane.

[0018] Furthermore, the probe molecules I and II can quickly recognize hydrogen sulfate ions in ppm level in water, and have no recognition effect on other anions in water. The other anions include Cl - , Br - , I -, NO3 - , SO4 2- , PF6 - , ClO4 - , OH - 。

[0019] Furthermore, both probe molecules I and II recognize diethyl ether and bisulfate in water by means of solution color change.

[0020] Advantages of the present invention: The present invention proposes a water-soluble colorimetric probe molecule synthesized by simple structural modification with phenol red indicator as the backbone, realizing the rapid recognition of trace diethyl ether molecules and bisulfate ions in water. This probe molecule has the advantages of cheap raw materials, simple synthesis, good water solubility, fast response speed, and naked-eye recognition. Description of the Drawings

[0021] Figure 1 is the preparation flow chart of probe molecules I and II;

[0022] Figure 2 is the 1H NMR spectrum of probe molecule I in Example 1 1 H NMR (400M, CDCl3, 298K);

[0023] Figure 3 is the ESI-MS spectrum (negative ion mode) of probe molecule I in Example 1;

[0024] Figure 4 is the sensing color development photo of probe molecule I for trace (1%, v / v) organic molecules in water in Example 1;

[0025] Figure 5 is the recognition color development photo of probe molecule I for various anions in water in Example 1 (I:

[0026] 1×10 -5 mol / L, anions in excess of 10 equivalents; the counter ion of the anion is tetra-n-butylammonium TBA + );

[0027] Figure 6 is the UV-vis absorption curve of probe molecule I after adding various anions in Example 1 (I: 1×10 -5 mol / L, anions in excess of 10 equivalents);

[0028] Figure 7 is the HSO4 - U-vis titration curve of probe molecule I (I concentration 1×10 -5 mol / L);

[0029] Figure 8is the UV absorption curve of probe molecule I in Example 1 in the presence of other anions (Cl - , Br - , I - , NO3 - , SO4 2- , PF6 - , ClO4 - , OH - ) upon addition of HSO4 - (1 equivalent of anion);

[0030] Figure 9 is the 1H NMR spectrum of probe molecule II-1 in Example 2 1 1H NMR (400 M, DMSO-d6, 298 K);

[0031] Figure 10 is the sensing colorimetric photograph of probe molecule II-1 in Example 2 for trace (1%, v / v) organic molecules in water;

[0032] Figure 11 is the recognition colorimetric photograph of probe molecule II-1 for various anions in water in Example 2 (II-1: 1×10 -5 mol / L; anion: 10 equivalents to II-1; counterion of anion is TBA + );

[0033] Figure 12 is the UV-vis absorption curve of probe molecule II-1 after addition of various anions in Example 2 (II-1: 1×10 -5 mol / L, anion in excess by 2 equivalents);

[0034] Figure 13 is the UV absorption curve of probe molecule II-1 in the presence of other anions (Cl - , Br - , I - , NO3 - , SO4 2- , PF6 - , ClO4 - , OH - ) upon addition of HSO4 - (concentration of II-1: 1×10 -5 mol / L, 1 equivalent of anion);

[0035] Figure 14 is the HSO4 - U-vis titration curve of probe molecule II-1 (II-1: 1×10 -5 mol / L); Detailed Embodiments

[0036] The following elaborates on the preferred embodiments of the present invention in conjunction with the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0037] Example 1: Preparation of Probe Molecule I and Its Recognition of Trace Amounts of Diethyl Ether Molecules and Bisulfate Ions in Water

[0038] Synthesis steps of probe molecule I: Weigh 3.0 g of phenol red, hexamethylenetetramine in an amount 15 times that of phenol red, and 55 mL of trifluoroacetic acid, and reflux the mixture at 100 °C overnight under a nitrogen atmosphere. After the reaction, add 3 mol / L hydrochloric acid aqueous solution (180 mL) to the above mixture, hydrolyze at 100 °C for 1.5 h, then cool to room temperature, filter by suction, extract with dichloromethane 10 times (60 mL × 10), dry the organic phase with anhydrous sodium sulfate, and rotary evaporate to obtain a crude red powder. Then, purify it by silica gel column chromatography with 200 mesh (eluent: dichloromethane / methanol) to obtain red probe molecule I (1.1 g, 31%). 1 H NMR (400 MHz, CDCl3, TMS, ppm) δ 11.19 (s, 2H, -OH), 9.83 (s, 2H, -CHO), 7.92 (d, 3 J = 8 Hz, 1H), 7.76 (td, 4 J = 8 Hz, 3 J = 1.2 Hz, 1H), 7.71 (td, 4 J = 8 Hz, 3 J = 1.2 Hz, 1H), 7.52 (d, 3 J = 2.44 Hz, 2H), 7.46 (dd, J = 8 and 2.4 Hz, 2H), 7.34 (d, 3 J = 7, 1H), 7.03 (d, 3 J = 8, 2H). ESI-MS (negative ion): m / z [M + H2O - H] - calcd. 427.0566 for C 21 H 16 O8S; found, 427.05022.

[0039] Figure 2 is the 1H NMR spectrum of probe molecule I 1 H NMR (400 M, D2O, 298 K); Figure 3 is the ESI-MS spectrum of probe molecule I (negative ion mode), where 427.05022 belongs to [M + H2O - H] - molecular ion peak; Figure 4It is the sensing colorimetric photo of probe molecule I for trace organic molecules (1%, v / v) in water. Only the ether molecule (number #12) can change the color of probe molecule I from red to yellow, while other organic molecules remain red unchanged (the blank control is pure water #1 on the left); Figure 5 It is the recognition colorimetric photo of probe molecule I for various anions in water. Only hydrogen sulfate (#10) changes the red solution to yellow, while other anions including Cl - , Br - , I - , NO3 - , SO4 2- , PF6 - , ClO4 - , OH - all remain red without obvious color change (the blank control is #1 without adding any anions); Figure 6 It is the UV-vis absorption curve of probe molecule I after adding various anions. Only HSO4 - significantly reduces the intensity of the absorption peak at 550 nm, while other anions cause almost no change or slight increase in the intensity of the 550 nm absorption peak; Figure 7 It is the ultraviolet absorption curve of probe molecule I in the coexistence of other anions (Cl - , Br - , I - , NO3 - , SO4 2- , PF6 - , ClO4 - , OH - ) after adding HSO4 - ; Figure 8 It is the HSO4 - U-vis titration curve of probe molecule I. The binding constant of HSO4 - calculated by fitting the titration curve using the BindFit program is 130656 M -1 (1:1 model).

[0040] Example 2: Preparation of probe molecule II-1 and its recognition of trace ether molecules and hydrogen sulfate in water

[0041] Synthesis steps: Weigh 1 mmol of molecule I and 2 mmol of the primary amine compound 1,3-diaminoureido and dissolve them in 100 mL of acetonitrile. After the above mixture is refluxed at 90 °C overnight, a red powder precipitates, and the imine condensation product a is obtained by filtration. Weigh the imine condensation product a (1 mmol) and dissolve it in 80 mL of ethanol. Slowly add 10 mmol of sodium borohydride methanol solution (10 mL × 3) in batches, and reflux and stir at 60 °C overnight. After the reaction is completed, the solution is rotary evaporated and deionized water (50 mL) is added, and it is continuously stirred at room temperature for 1 h, and then extracted with dichloromethane solution to obtain the final product probe molecule II-1 (38%). 1 H NMR (400 MHz, DMSO-d6, ppm) δ 10.48 (s, 2H, OH), 7.90 (m, 1H), 7.81 (m, 1H), 7.38 (d, 2H), 7.24 (d, 2H) 7.12 (s, 1H), 6.98 (s, 1H), 6.74 (m, 1H), 6.24 (s, 1H), 3.43 (m, 8H).

[0042] Figure 9 is the NMR spectrum of probe molecule II-1 1 H NMR, Figure 10 is the sensing colorimetric photo of probe molecule II-1 for trace (1%, v / v) organic molecules in water. Among them, only the ether molecule (number #12) can change the probe molecule I from red to yellow, and other organic molecules remain red unchanged (the blank comparison is pure water #1 on the left); Figure 11 is the recognition colorimetric photo of probe molecule II-1 for various anions in water (II-1 concentration: 1×10 -5 mol / L; anion: 10 equivalents to II-1), among which only hydrogen sulfate (#10) changes the red solution to yellow, and other anions including Cl - , Br - , I - , NO3 - , SO4 2- , PF6 - , ClO4 - , OH - all remain red without obvious color change (the blank comparison is #1 without adding any anion); Figure 12 is the UV-vis absorption curve after adding various anions to probe molecule II-1 (II-1 concentration: 1×10 -5 mol / L, anion in excess of 10 equivalents), among which only HSO4 - significantly reduces the absorption peak intensity at 560 nm, and other anions cause the absorption peak intensity at 560 nm to remain almost unchanged or slightly increase; Figure 13 is for probe molecule II-1 in the coexistence of other anions (Cl- , Br - , I - , NO3 - , SO4 2- , PF6 - , ClO4 - , OH - ) Add HSO4 - UV absorption curve; Figure 14 is HSO4 of probe molecule II-1 - U-vis titration curve. The binding constant of HSO4 calculated by fitting the titration curve using the BindFit program is 13004 M - (1:1 model). -1 (1:1 model).

[0043] The above are only embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present invention by the same token.

Claims

1. Preparation and application of a colorimetric probe molecule for identifying diethyl ether and bisulfate in water, characterized in that The structure of the probe molecule is shown in Formula 1: Among them, in the probe molecule II, R-(NH2) n is an aliphatic or aromatic primary amine compound, the number of amino groups n ≧ 1, and R-(NH2) n can be but is not limited to the following structures:

2. Preparation and application of a colorimetric probe molecule for identifying ethyl ether and bisulfate ion in water, characterized in that, It includes the following steps: Step 1, Preparation of probe molecule I: Weigh an appropriate amount of phenol red, hexamethylenetetramine which is 15 times the amount of phenol red, and an appropriate amount of trifluoroacetic acid, and reflux the mixture at 100 °C overnight under a nitrogen atmosphere. After the reaction is completed, add 3 mol / L hydrochloric acid aqueous solution to the above mixture, hydrolyze it at 100 °C for 1.5 h, then cool it to room temperature, filter by suction, extract it several times with dichloromethane, dry it with anhydrous sodium sulfate, evaporate to dryness and purify to obtain probe molecule I. Step 2, Preparation of probe molecule II: Weigh 1 mmol of molecule I and n mmol (n is the number of primary amine functional groups) of primary amine compound R-(NH2) n Dissolve them in an appropriate amount of organic solvents, which include methanol, ethanol, acetonitrile, N,N-dimethylformamide, dichloromethane, tetrahydrofuran, acetonitrile, etc. After refluxing the above mixture overnight, the imine condensation product a is obtained by filtration or rotary evaporation. The imine condensation product a is dissolved in ethanol, and 10 equivalents of sodium borohydride methanol solution are added slowly in batches, and the mixture is stirred overnight at the reflux temperature. After the reaction is completed, the solution is rotary evaporated to dryness, deionized water is added, and the mixture is stirred at room temperature for 1 h. Then, according to the water solubility of the product, the final product probe molecule II is obtained by filtration or extraction with dichloromethane solution.

3. Preparation and application of a colorimetric probe molecule for identifying diethyl ether and hydrogen sulfate ion in water, characterized in that: The core skeleton structure of the probe molecule is phenol red.

4. Preparation and application of a colorimetric probe molecule for identifying diethyl ether and hydrogen sulfate ion in water, characterized in that: The structures of probe molecules I and II are obtained by substituting aldehyde groups or aminomethyl groups at the ortho-position of the phenolic group of the phenol red skeleton.

5. Preparation and application of a colorimetric probe molecule for identifying ethyl ether and bisulfate in water, characterized in that: The R-(NH2) n may be any aliphatic or aromatic primary amine compound capable of undergoing an imine condensation reaction with I, and the number of amino groups n ≧ 1.

6. Preparation and application of a colorimetric probe molecule for identifying diethyl ether and bisulfate ion in water, characterized in that: Probe molecules I and II can selectively recognize diethyl ether molecules from trace organic molecules in water, and have no recognition effect on other organic molecules in water.

7. The application according to claim 6, wherein: The other organic molecules include methanol, ethanol, dimethyl sulfoxide, N,N-dimethylformamide, tetrahydrofuran, benzene, toluene, cyclohexane, dichloromethane, acetonitrile, acetone, petroleum ether and 1,4-dioxane.

8. Preparation and application of a colorimetric probe molecule for identifying diethyl ether and hydrogen sulfate in an aqueous phase according to claim 1, characterized in that: Probe molecules I and II can selectively recognize hydrogen sulfate ions at the ppm level in the aqueous phase, and have no recognition effect on other anions in water.

9. The application according to claim 8, characterized in that: Said other anions include Cl - , Br - , I - , NO3 - , SO4 2- , PF6 - , ClO4 - , OH - .

10. The application according to claim 6 or 8, characterized in that: The recognition effects of probe molecules I and II on diethyl ether and hydrogen sulfate in water are both achieved by rapid color change.

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