CN109651219B

CN109651219B - Organic gel compound of azophenylthiourea derivative, preparation method, organic gel and application

Info

Publication number: CN109651219B
Application number: CN201811640806.1A
Authority: CN
Inventors: 曹新华; 黒笑涵; 高爱萍; 邹国栋; 于永生
Original assignee: Henan University of Urban Construction; Xinyang Normal University
Current assignee: Henan University of Urban Construction; Xinyang Normal University
Priority date: 2018-12-29
Filing date: 2018-12-29
Publication date: 2020-11-03
Anticipated expiration: 2038-12-29
Also published as: CN109651219A

Abstract

The invention belongs to the technical field of supramolecular chemistry, and particularly relates to an organogel compound of an azophenylthiourea derivative, a preparation method, organogel and application. The organic gel compound of the azophenylthiourea derivative has a structure shown in a formula I. The organogel compound of the azophenylthiourea derivative can form gel in n-hexane, petroleum ether, dimethyl sulfoxide, acetonitrile or ethanol solvent. The organogel compound of the azophenylthiourea derivative can realize the effect of controlling Hg²⁺、Cu²⁺、Fe³⁺Volatile acid and organic amine, and the detection method is simple, and can realize Hg by visual observation without adopting instruments²⁺、Cu²⁺、Fe³⁺And detecting volatile acid or organic amine.

Description

Organic gel compound of azophenylthiourea derivative, preparation method, organic gel and application

Technical Field

The invention belongs to the technical field of supramolecular chemistry, and particularly relates to an organogel compound of an azophenylthiourea derivative, a preparation method, organogel and application.

Background

Copper is a basic trace element present in the animal and human body and is involved in a wide range of metabolic processes as a cofactor for certain enzymes and proteins. However, high copper content can cause serious harm to life health, resulting in biochemical disorders, physiological dysfunction and various pathological changes of internal organs.

Mercury is the only metal which is liquid and easy to flow at normal temperature, is mainly used in scientific instruments, mercury boilers, mercury pumps and mercury gas lamps, is also widely applied in medicine, and is visible everywhere in people's lives for a long time. Mercury in the environment can be enriched by passive plants, and is converted into organic mercury with higher toxicity through biotransformation, and mercury in various forms can enter human body through water and food chain, so that toxic effect is generated on human body, and brain injury and death can be caused after long-term exposure to high-mercury environment. Therefore, trace mercury detection in the environment is of paramount importance.

Iron is one of essential elements for human body, has important effect on human metabolism and health, and can cause iron-deficiency anemia due to insufficient iron content in blood. Although the iron contained in the water does not harm the health of human bodies, the water with high iron content is easy to grow iron bacteria in the pipeline, the turbidity of the water is increased, and the water generates special color, odor and taste, so the water is not delicious to drink and has a rust taste. Meanwhile, the iron content in the water body has important influence on industrial and agricultural production and daily life. In addition, the iron ions play a certain role in the industries of chemical production, medicine, food, health and the like, so the determination of the content of the iron ions is valuable.

Volatile acids, also known as gaseous acids, such as hydrochloric acid and trifluoroacetic acid, are highly volatile. Such acids are commonly used as pharmaceutical, pesticidal intermediates, biochemical reagents, organic synthetic reagents. Trifluoroacetic acid is used for synthesizing fluorine-containing compounds, pesticides and dyes; is a catalyst for esterification and condensation reactions; hydroxy and amino protecting agents for the synthesis of sugars and polypeptides; also used as a beneficiation agent and for organic synthesis. However, these acids have strong irritation to eyes, mucous membrane, respiratory tract and skin, and may cause spasm, inflammation, edema, chemical pneumonia, pulmonary edema and death of throat and bronchus after inhalation, and symptoms such as burning sensation, cough, wheeze, shortness of breath, laryngitis, headache, nausea and vomiting, and skin burn.

Organic amine is a trace compound commonly existing in the atmosphere, has stronger alkalinity than inorganic ammonia, and is also one of important nitrogenous organic compounds. At present, about 150 kinds of organic amine are identified in the atmosphere, the main components comprise 24 kinds of methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, propylamine, aniline and the like, the organic amine has a smooth olfaction threshold value and is low in olfaction threshold value, and when the organic amine reaches a certain concentration in the air, the organic amine is not only unpleasant in olfaction, but also can cause damage to human health.

Therefore, the method has important practical significance for sensitively detecting copper ions, iron ions, mercury ions, gaseous acids and organic amines, and has environmental protection value. In the prior art, the detection of the copper ions, the iron ions, the mercury ions, the gaseous acid and the organic amine is usually realized by adopting an instrumental analysis method, and the detection method and the detection process are relatively complicated.

The small molecule gel is a soft material between a liquid phase and a solid phase as a novel functional material. The material usually contains structural groups and functional groups, and micro-nano network structures with different sizes are formed through non-covalent interaction between the structural groups, so that a large number of solvent molecules are fixed in the network; the introduction of functional groups can make the gel sensitively respond to external stimuli such as light, heat, pH, biomolecules, ultrasound, metal ions and the like, and cause changes of optical, electrical, molecular conformation and even chemical properties of a system, so that the material has the capability of information storage, transmission and processing. The prior art has been concerned with the use of small molecule gels for the detection of metals or gaseous acids, if a new organogel compound could be developed for use in Hg as well²⁺、Cu²⁺、Fe³⁺The detection of the volatile acid and the organic amine has good application prospect.

Disclosure of Invention

The invention aims to provide an organogel compound of an azophenylthiourea derivative, which can be used for detecting Hg²⁺、Cu²⁺、Fe³⁺Volatile acids and organic amines.

The second object of the present invention is to provide a method for preparing an organogel compound of an azophenylthiourea derivative.

A third object of the present invention is to provide an organogel.

The fourth purpose of the invention is to provide the application of the organic gel compound of the azophenylthiourea derivative in the detection of volatile acid.

In order to achieve the above purpose, the technical scheme of the invention is as follows:

an organogel compound of an azophenylthiourea derivative having the structure shown in formula I:

the preparation method of the organogel compound comprises the following steps:

mixing 4-dimethylamino azobenzene-4' -thioisocyanate, N- (2-aminoethyl) -3,4, 5-tri (dodecyloxy) benzamide and anhydrous tetrahydrofuran, stirring and refluxing for 10-13 h, then decompressing and distilling out tetrahydrofuran, and purifying the residual product by a column to obtain the product.

The molar ratio of the 4-dimethylamino azobenzene-4' -thioisocyanate to the N- (2-aminoethyl) -3,4, 5-tris (dodecyloxy) benzamide is 1: 1; the reflux temperature is 90-95 ℃.

An organogel prepared by a process comprising the steps of: heating the organogel compound of the azophenylthiourea derivative in an organic solvent to dissolve, and then cooling to room temperature to obtain the azophenylthiourea derivative, wherein the organic solvent is any one of n-hexane, petroleum ether, dimethyl sulfoxide, acetonitrile and ethanol.

The heating temperature for heating to dissolve is above 80 ℃.

The critical gel concentration of the organogel compound of the azophenylthiourea derivative in n-hexane was 1.9 mg/ml.

The critical gel concentration of the organogel compound of the azophenylthiourea derivative in petroleum ether is 1.8 mg/ml.

The critical gel concentration of the organogel compound of the azophenylthiourea derivative in dimethyl sulfoxide was 12.5 mg/ml.

The critical gel concentration of the organogel compound of the azophenylthiourea derivative in acetonitrile was 12.5 mg/ml.

The critical gel concentration of the organogel compound of the azophenylthiourea derivative in ethanol is 25.0 mg/ml.

The organic gel compound of the azophenylthiourea derivative is used for detecting Hg²⁺、Cu²⁺、Fe³⁺And volatile acids or organic amines.

The critical gel concentration mentioned above means the lowest concentration at which a gel is formed.

The volatile acid is any one of trifluoroacetic acid, nitric acid and hydrochloric acid.

The organic amine is any one of triethylamine, tripropylamine, ammonia water and diethylamine.

The organogel compound of the azophenylthiourea derivative has azo groups, thiourea groups and amide groups, and has metal ion sensing characteristics. The organic gel compound of the azophenyl thiourea derivative of the invention mainly detects mercury ions through intramolecular cyclization reaction, and H is lost in the process of the molecular cyclization reaction₂And S, further changing the ultraviolet visible absorption spectrum of the material. The organogel compound of the azophenylthiourea derivative has the same detection mechanism for iron ions and copper ions, and both the iron ions and the nitrogen-nitrogen double bonds in the compound 1 are coordinated, so that the original absorption spectrum of the compound 1 is changed. The organogel compound of the azophenylthiourea derivative can also be used for detecting volatile acid and organic amine, wherein the volatile acid is detected by reacting protons in the acid with terminal amino groups to generate quaternary ammonium salt, the color of the solution is changed, and when the organic amine is detected, the color of the solution or solid is restored to the original appearance through acid-base reaction.

The organogel compound of the azophenylthiourea derivative can realize the para-Hg²⁺、Cu²⁺、Fe³⁺Volatile acid and organic amine, and the detection method is simple and rapid, and can be distinguished by naked eyes without adopting an instrument.

Drawings

FIG. 1 is a drawing showing organogel compounds of azophenylthiourea derivatives of formula I¹HNMR spectrogram;

FIG. 2 shows the organic nature of an azophenylthiourea derivative of the formula IOf gel compounds¹³CNMR spectrogram;

FIG. 3 is a schematic representation of the morphology of organogels formed from organogel compounds of azophenylthiourea derivatives in different solvents;

FIG. 4 is an SEM image of a xerogel formed from organogel compounds of azophenylthiourea derivatives in different solvents;

FIG. 5 is a schematic diagram of the morphology of compound 1 after addition of different metal ions to the acetonitrile solution;

FIG. 6 shows the UV-VIS absorption spectrum of the acetonitrile solution of compound 1 and different metal ions added;

FIG. 7 shows the addition of Hg separately²⁺,Fe³⁺,Cu²⁺The ultraviolet-visible absorption spectrum of the acetonitrile solution of the compound 1;

FIG. 8 is a graph of the UV-VIS absorption spectrum of the acetonitrile solution of compound 1 after trifluoroacetic acid and triethylamine are added and the corresponding linear curves;

FIG. 9 is a schematic diagram of the effect of different gaseous acids on the morphology of film 1;

fig. 10 is a schematic diagram of the effect of different organic amines on the morphology of dark brown film 1;

fig. 11 is a graph showing the uv-vis absorption spectra and corresponding linear curves of the dark brown film 1 pair treated with different concentrations of triethylamine.

Detailed Description

Example 1

This example of an organogel compound of an azophenylthiourea derivative has the structure shown in formula I:

the preparation route of the organogel compound of the azophenylthiourea derivative of this example is as follows:

the preparation method comprises the following steps:

1.0g (3.54mmol) of 4-dimethylaminoazobenzene-4' -thioisocyanate, 2.54g (3.54mmol) of N- (2-aminoethyl) -3,4, 5-tris (dodecyloxy) benzamide are mixed uniformly in 100ml of anhydrous tetrahydrofuran, then the mixture is refluxed for 12h at 90 ℃, then the tetrahydrofuran is evaporated out under reduced pressure, the residual product is purified by a silica gel column, the eluent is methanol/dichloromethane (1/1200, v/v), yellow powder is finally obtained, namely the compound shown in the formula I, the yield is 70.5 percent,¹HNMR(600MHz,DMSO-d₆):9.70(s,1H),8.36(s,1H),7.92(s,1H),7.75(d,J＝9.0Hz,2H),7.69(d,J＝9.0Hz,2H),7.58(d,J＝9.0Hz,2H),7.15(s,2H),6.82(d,J＝9.0Hz,2H),3.99(t,J＝6.6Hz,4H),3.91(t,J＝6.6Hz,2H)3.74(d,J＝3.6Hz,2H),3.50(d,J＝3.6Hz,2H),3.04(s,6H),1.72-1.62(m,6H),1.43-1.39(m,6H),1.30-1.23(m,48H),0.84(t,J＝6.6Hz,9H)；¹³CNMR(150MHz,DMSO-d₆):181.3,166.7,152.9,152.8,149.4,143.4,141.1,140.7,129.8,1249.,123.4,122.8,112.1,106.8,73.1,69.3,44.2,31.8,30.3,29.5,29.3,29.2,26.1,22.5,14.3.HRMScalculated for C₆₀H₉₉N₆O₄S[M+H]⁺999.7449,found:999.7474.

in the preparation method of the organic gel compound of the azophenylthiourea derivative, the reflux temperature can be 95 ℃ and the reflux time is 10 hours.

Process for preparing compounds of formula I¹The H NMR spectrum is shown in FIG. 1, and the compound shown in the formula I¹³The CNMR spectra are shown in FIG. 2.

Example 2

The organogel compound of the azophenylthiourea derivative (compound 1 for short) prepared in example 1 and an organic solvent were placed in a sealed vial, heated to about the boiling point of the solvent (80 ℃ or higher) to dissolve the organogel compound of the azophenylthiourea derivative, and then allowed to stand and cool to 25 ℃ to observe the gelling ability in different solvents. The gels are all thermodynamically reversible and become flowable sols upon heating, and the specific gel properties are shown in table 1.

TABLE 1 gellation state of organogel compounds of azophenylthiourea derivatives in different solvents

Organic solvent	Gel state	Organic solvent	Gel state
				DMF	S
	1, 4-dioxane	S
			N-hexane	G(1.9)	Acetonitrile	G(12.5)
Methanol	P	Ethanol					G(25.0)
			Acetone (II)	P	Ethyl acetate	P
Petroleum ether	G(1.8)	Toluene					S
			Dimethyl sulfoxide	G(12.5)	Tetrahydrofuran (THF)	S
Methylene dichloride	S	Chloroform					S

Note that: wherein G represents gel, PG represents partial gel, S represents dissolution, and NI represents insolubility; the minimum gelling concentration in mg/ml is indicated in parentheses.

As is clear from table 1, the organogel compound of the azophenylthiourea derivative of the present invention can form an organogel in a solvent of n-hexane, petroleum ether, dimethyl sulfoxide, acetonitrile, or ethanol.

The organogel compound of the azophenylthiourea derivative has good stability in petroleum ether, n-hexane, dimethyl sulfoxide, ethanol and acetonitrile solvent, is yellow opaque, can be placed for several months, and has the appearance shown in figure 3, wherein in figure 3 a) is the organogel formed in the petroleum ether solvent, b) is the organogel formed in the n-hexane solvent, c) is the organogel formed in the DMSO solvent, d) is the organogel formed in the ethanol solvent, and e) is the organogel formed in the acetonitrile solvent.

Respectively diluting the formed organogels with corresponding organic solvents, dispersing the diluted organogels on a mica plate, performing freeze drying to form xerogels, and then respectively performing a scanning electron microscope test, wherein the results are shown in figure 4, and a), b), c), d) and e) in figure 4 are SEM images of the xerogels in petroleum ether, n-hexane, dimethyl sulfoxide, ethanol and acetonitrile solvents, and as can be seen from a) and b) in figure 4, the organogels formed in the n-hexane and the petroleum ether solvents are porous network structures formed by nano fibers, wherein the width of the nano fibers is 300nm, and the length of the nano fibers is tens of microns; compared with the organogel formed in ethanol and acetonitrile, the nano-fiber gel formed in n-hexane and petroleum ether is dispersed more uniformly; as shown in fig. 4d) and 4e), the width of the nanofiber structure of the organogel formed in ethanol and acetonitrile was 300 to 400nm, and the length was several tens of micrometers. The nanofiber structure described above tends to stack and wind into a node, like a pond with many tadpoles; as shown in FIG. 4c), the organogel formed in the dimethylsulfoxide solvent exhibits irregular micron bands, ranging from 1 to 3 μm in width and several tens of microns in length.

Experimental example 1

The detection research of the organic gel compound (compound 1) of the azophenylthiourea derivative shown as the formula I on metal ions is carried out, and Ag is respectively selected⁺,Cd²⁺,Fe²⁺,K⁺,Mg²⁺,Mn²⁺,Na⁺,Ni²⁺,Pb²⁺,Zn²⁺,Hg²⁺,Fe³⁺,Cu²⁺Experiments were performed.

To a solution of compound 1 in acetonitrile (c ═ 10)^-4M) adding different metal ions Ag⁺,Cd²⁺,Fe³⁺,K⁺,Mg²⁺,Mn²⁺,Na⁺,Ni²⁺,Pb²⁺,Zn²⁺,Hg²⁺,Fe³⁺,Cu²⁺Adding Fe as shown in FIG. 5a³⁺The latter solution turns from yellow to wine red, Hg is added²⁺The latter solution turns from yellow to bright red, Cu is added²⁺Then the solution is changed from yellow to ginger yellow, and the color is not obviously changed after other metal ions are added; shown in FIG. 5b as Fe³⁺And Cu²⁺All acetonitrile solutions of (1) were colorless and used as a control to exclude Fe³⁺And Cu²⁺FIG. 5 shows the effect of compound 1 on Hg, which is inherent in color²⁺,Fe³⁺,Cu²⁺Has selectivity.

To further demonstrate that Compound 1 is para Hg²⁺,Fe³⁺,Cu²⁺To acetonitrile solution of compound 1 and addition of Ag⁺,Cd²⁺,Fe³⁺,K⁺,Mg²⁺,Mn²⁺,Na⁺,Ni²⁺,Pb²⁺,Zn²⁺,Hg²⁺,Fe³⁺,Cu²⁺The result of ultraviolet-visible detection of the acetonitrile solution of the compound 1 after the reaction was shown in FIG. 6, and it was found from FIG. 6 that the ultraviolet-visible absorption spectrum of the acetonitrile solution of the compound 1 had two absorption peaks at 261nm and 423nm and the molar absorption coefficients thereof were 3.11X 10, respectively⁴And 3.52X 10⁴M^-1cm^-11.0eq of Hg was added²⁺Then, a new absorption peak appears at 531nm, the absorption peak at 261nm is red-shifted by 9nm to 270nm, and the absorption peak at 423nm is red-shifted by 25nm to 448 nm; when 1.0eq. Fe was added³⁺When the absorption peak is in the range of 549nm, the absorption peaks at 270nm and 448nm are blue-shifted to 248nm and 421 nm. When other metal ions are added into the acetonitrile solution of the compound 1, the absorbance of the absorption peak of the ultraviolet absorption spectrum is changed, but the position of the peak is not obviously moved.

Compound 1 p Hg²⁺,Fe³⁺,Cu²⁺The detection ability of (a) was investigated by the change of the ultraviolet-visible absorption spectrum.

As in FIG. 7a, Hg was added²⁺Previously, there were two absorption peaks at 261nm and 423nm for the solution of Compound 1, with Hg²⁺The titration amount is increased, the light absorbance at 423nm is gradually attenuated, a new absorption peak appears at 541nm and is gradually enhanced, and the equal light absorbance point appearing at 475nm represents Hg²⁺Reaction with Compound 1; when Hg is contained²⁺At an addition amount of 1.2eq, the absorbance of two absorption peaks at 261nm and 423nm reached the minimum. FIG. 7 a', ratio of absorbance at 541nm to absorbance at 423nm and Hg²⁺Has a linear relationship with the addition of (1) and has a linear coefficient R of 0.9931, compound 1 to Hg²⁺Has a minimum detection limit of 9.22 × 10^-9mol/L. The mercury ion detection of the compound 1 is mainly realized through intramolecular cyclization reaction, and H is lost in the process of the intramolecular cyclization reaction₂S, the structure of the compound 1 is changed as follows after mercury ions are added:

as in fig. 7b, with Fe³⁺The titration amount is increased, the light absorbance at 423nm is gradually reduced, a new absorption peak appears at 549nm and the light absorbance is gradually increased, and the equal light absorbance points appearing at 549nm indicate Fe³⁺Reacting with the compound 1 to form a complex; FIG. 7 b', ratio of absorbance at 549nm to absorbance at 423nm and Fe³⁺Has a linear relation with the addition amount of the compound (1) to Fe, the linear coefficient R is 0.9941³⁺Has a minimum detection limit of 1.39 × 10^-9mol/L. The compound 1 is mainly used for detecting iron ions through the coordination of the iron ions and nitrogen-nitrogen double bonds in azobenzene, so that the original absorption spectrum is changed, and the iron ions are identified by naked eyes.

As in FIG. 7c, with Cu²⁺The titration amount is increased, the light absorbance at 423nm is gradually reduced, a new absorption peak appears between 500nm and 900nm, the light absorbance is gradually increased, and the absorption peak is subjected to 26nm red shift along with the titration of copper ions and is red-shifted from 423nm to 449 nm; FIG. 7 c', ratio of absorbance at 600nm to absorbance at 423nm and Cu²⁺Has a linear relationship with the addition amount of (1) to Cu, the linear coefficient R is 0.9946²⁺Has a minimum detection limit of 5.99X 10^-9mol/L. The detection of the compound 1 on the copper ions is mainly realized by changing the original absorption spectrum through the coordination of the copper ions and nitrogen-nitrogen double bonds in azobenzene, so that the naked eye identification on the copper ions is realized.

The detection mechanism of the compound 1 on iron ions and copper ions is the same, and both the copper ions or the iron ions and nitrogen in the compound 1 are subjected to double coordination, so that the original absorption spectrum of the compound 1 is changed, wherein the coordination effect of the copper ions or the iron ions and the compound 1 is shown as follows:

wherein M is Cu²⁺Or Fe³⁺。

Experimental example 2

The organogel compound (compound 1) of the azophenylthiourea derivative shown in the formula I is used for detecting and researching volatile acid and organic amine, and trifluoroacetic acid and triethylamine are taken as examples for research.

To an acetonitrile solution (c ═ 10) of an organogel compound (compound 1) of an azophenylthiourea derivative represented by the formula i^-5M), as shown in fig. 8a, with the addition of trifluoroacetic acid, the absorption peak at 423nm gradually decreased, a new absorption peak appeared at 548nm and the absorbance at that point gradually increased, and isoabsorbance points appeared at 479 nm. After trifluoroacetic acid is added, the acetonitrile solution of the compound 1 gradually changes from yellow to purple, when the adding amount of the trifluoroacetic acid is 450eq, the absorbance change at 423nm and 548nm reaches the limit, and 479nm is the equal absorbance point. As shown in fig. 8 a', the ratio of the absorbance at 548nm to the absorbance at 423nm was in a linear relationship with the amount of trifluoroacetic acid added, the linear coefficient R was 0.9966, and the lowest limit of detection of trifluoroacetic acid by compound 1 was 3.1 × 10^-9mol/L. The principle of detecting gaseous acid by the compound 1 is as follows: the color of the compound 1 solution is changed by reacting protons in the acid with terminal amino groups in the compound 1 to form a quaternary ammonium salt.

Theoretically, the solution of compound 1 with trifluoroacetic acid added can further detect organic amines by acid-base reaction. As shown in FIG. 8b, triethylamine was added to the acetonitrile solution of Compound 1 to which trifluoroacetic acid was added, the solution changed from violet to yellow in color, the absorption peak at 548nm gradually decreased with the addition of triethylamine (up to 250eq), the absorption peak at 423nm gradually recovered, and an isoabsorbance point existed at 479 nm. As shown in FIG. 8 b', the ratio of the absorbance at 423nm to the absorbance at 528nm was linear with the amount of triethylamine added, the linear coefficient R was 0.9927, and the minimum detection limit of triethylamine was 2.77X 10^-9mol/L。

The detection of the gaseous volatile acid is that the proton in the acid reacts with the amino group at the terminal position to generate quaternary ammonium salt, the color of the solution is changed, and when the organic amine is detected, the color of the solution or solid is changed back through the acid-base reaction, wherein the structural change of the compound 1 is shown as follows.

Film 1 was prepared by dissolving compound 1 in methylene chloride and then spreading it on a quartz plate to reduce the amount of compound 1 used. The film 1 was tested for selectivity to volatile acids and organic amines. Experiments prove that as shown in fig. 9, the color of the film 1 is rapidly changed from yellow to dark brown under the excitation of trifluoroacetic acid, hydrochloric acid or nitric acid for 2-30 s; since formic acid, acetic acid, and propionic acid are weak in activity, film 1 is not sensitive thereto, and the color of film 1 is not changed.

Dark brown film 1 after response to volatile acids was used to test its sensitivity to organic amines. As shown in fig. 10, the film 1 with the dark brown color is responded by triethylamine, tripropylamine, ammonia water and diethylamine, the color of the film changes from the dark brown color to yellow color, and the ethylenediamine and aniline have weak volatility and alkalinity, so that the color of the film 1 can not be recovered from the dark brown color to yellow color.

Film 1 was studied by uv-vis spectroscopy under the influence of trifluoroacetic acid concentration. As shown in fig. 11a, film 1 has a maximum absorption peak at 399nm, and film 1 changes color from yellow to dark brown in trifluoroacetic acid atmosphere, and as the concentration of trifluoroacetic acid increases from 3ppm to 33ppm, the absorption peak at 399nm gradually decays, and a new absorption peak appears at 530nm and gradually increases. And the ratio of the absorbance at 530nm to the absorbance at 399nm is in a linear relationship with the concentration of trifluoroacetic acid, the linear curve is shown in fig. 11b, the linear coefficient R is 0.9986, and the lowest detection limit of film 1 for trifluoroacetic acid is 0.0848 ppb.

Various other modifications and changes may be made by those skilled in the art based on the above-described technical solutions and concepts, and all such modifications and changes should fall within the scope of the claims of the present invention.

Claims

1. An organogel compound of an azophenylthiourea derivative, characterized by having a structure represented by formula i:

2. a method of preparing the organogel compound of claim 1, comprising the steps of:

3. The process according to claim 2, wherein the molar ratio of 4-dimethylaminoazobenzene-4' -thioisocyanate to N- (2-aminoethyl) -3,4, 5-tris (dodecyloxy) benzamide is 1: 1; the reflux temperature is 90-95 ℃.

4. An organogel characterized by being prepared by a process comprising the steps of: heating the organogel compound of the azophenylthiourea derivative of claim 1 in an organic solvent to dissolve the organogel compound, and then cooling the organogel compound to room temperature to obtain the azophenylthiourea derivative, wherein the organic solvent is any one of n-hexane, petroleum ether, dimethyl sulfoxide, acetonitrile and ethanol.

5. The organogel according to claim 4, characterized in that the critical gel concentration of the organogel compound of azophenylthiourea derivative in n-hexane is 1.9 mg/ml.

6. The organogel according to claim 4, characterized in that the critical gel concentration of the organogel compound of the azophenylthiourea derivative in petroleum ether is 1.8 mg/ml.

7. The organogel according to claim 4, characterized in that the critical gel concentration of the organogel compound of the azophenylthiourea derivative in dimethyl sulfoxide is 12.5 mg/ml.

8. The organogel according to claim 4, characterized in that the critical gel concentration of the organogel compound of the azophenylthiourea derivative in acetonitrile is 12.5 mg/ml.

9. The organogel according to claim 4, characterized in that the critical gel concentration of the organogel compound of azophenylthiourea derivative in ethanol is 25.0 mg/ml.