CN107474023B

CN107474023B - Asymmetric squarylium cyanine dye probe based on substituted aniline and preparation method and application thereof

Info

Publication number: CN107474023B
Application number: CN201710822064.3A
Authority: CN
Inventors: 刘晓骞; 李娜; 王建浩; 闵婕; 林晨; 周苏; 刘雪芹
Original assignee: Changzhou University
Current assignee: Changzhou University
Priority date: 2017-09-13
Filing date: 2017-09-13
Publication date: 2020-02-14
Anticipated expiration: 2037-09-13
Also published as: CN107474023A

Abstract

The invention belongs to the field of chemical analysis and test, and particularly relates to an asymmetric squarylium cyanine dye probe based on substituted aniline, and a preparation method and application thereof. Chloridizing 3, 4-dihydroxy-3-cyclobutene-1, 2-diketone, reacting with N, N-dibutylaniline, converting a chlorine substituent in a product into hydroxyl in an acid solution, and finally reacting with 3-butyl-6-iodo-2-methyl-benzothiazole to obtain a final product.

Description

Asymmetric squarylium cyanine dye probe based on substituted aniline and preparation method and application thereof

Technical Field

The invention belongs to the field of chemical analysis and test, and particularly relates to an asymmetric squarylium cyanine dye probe based on substituted aniline, and a preparation method and application thereof.

Background

Cadmium is not an essential element of the human body. Cadmium in the human body is absorbed from the external environment after birth, and is mainly absorbed into the body through food, water and air and accumulated. Cadmium stimulates respiratory tracts, causes olfaction loss, gingival macula or gradually turns yellow after long-term exposure, and cadmium compounds are not easily absorbed by intestinal tracts, but can be absorbed by human bodies through breathing and accumulated in livers or kidneys to cause harm, particularly to kidneys. It can also lead to osteoporosis and malacia.

Iron ions are also an important metal element and are an important component in human hemoglobin, myosin and cytochrome. Research shows that iron deficiency can cause iron deficiency anemia and aplastic anemia, and easily causes limb weakness and asthma.

Therefore, the design and synthesis of chemical sensors with selective recognition function for cadmium ions and iron ions have attracted much attention in recent years, and have become a research hotspot in the fields of chemical science, environmental science, life science and the like.

Disclosure of Invention

The invention provides an asymmetric squaraine dye probe based on substituted aniline, which has the structure

The invention also provides a preparation method of the dye probe, which comprises the following steps:

(1) dissolving 3, 4-dihydroxy-3-cyclobutene-1, 2-dione in toluene, adding thionyl chloride and DMF (dimethylformamide), refluxing the mixture for 6 hr, removing solvent, dissolving the residue with hexane, storing in refrigerator, separating pale yellow crystals,

adding thionyl chloride and DMF, adding a drop of anhydrous DMF when the thionyl chloride is added to a half amount, continuously adding the rest of thionyl chloride at room temperature,

(2) dissolving the light yellow crystal obtained in the step (1) and N, N-dibutylaniline in toluene, refluxing for 6 hours at 80 ℃, removing the solvent under reduced pressure to obtain a solid,

(3) dissolving the solid obtained in the step (2) in a solution consisting of acetic acid, water and hydrochloric acid, refluxing for 2 hours at 100 ℃, removing the solvent under reduced pressure to obtain a product,

(4) dissolving the product obtained in the step (3) and 3-butyl-6-iodo-2-methyl-benzothiazole in a solvent system of toluene and n-butanol with the volume ratio of 1:1, heating and refluxing at 110 ℃, removing the solvent by decompression, separating by column chromatography to obtain the final product,

the chemical reaction formula of the preparation method is as follows:

the invention also provides an application of the dye probe, which comprises the following steps: for selective recognition of Cd²⁺And Fe³⁺，

In the structure of the prepared probe, carbonyl on a squaric acid ring plays an important role in identifying metal ions as a target spot for ion identification: the carbonyl on the squaric acid ring has lone pair electrons and can coordinate with metal ions lacking electrons through the action of hydrogen bonds; in the design and synthesis of the probe, the sulfur atom on the benzothiazole can also provide a lone pair of electrons, and the lone pair of electrons and the carbonyl on the squaric acid ring act together to provide stronger coordination; in the probe structure, a semi-open type annular structure is formed among sulfur atoms, four-membered ring carbonyl and carbon-carbon double bonds, each structure synergistically plays a role in selecting ions, has a certain spatial aperture, is suitable for coordination of ions with specific sizes under the action of a certain solvent, can further play a role in selecting metal ions,

the technology solves the problem of Cd in different solvent systems²⁺And Fe³⁺Problem of Selective recognition, from the reaction phenomena viewpoint, addition of Fe³⁺After complexation, the absorption of the probe dye is quenched, and the color of the solution is changed from blue to colorless; adding Cd²⁺After complexation, a red shift of the absorption of the probe dye is caused, the color changing from blue to purple.

The invention has the beneficial effects that: the synthesis method is simple, the reaction conditions are easy to control, and pure products can be obtained through simple treatment after the reaction is finished; as Fe³⁺And Cd²⁺The asymmetric squaraine dye probe of the chemical sensor for detection has high sensitivity and good selectivity, and can respectively and selectively identify Fe in different solvents³⁺And Cd²⁺Fe can be identified, for example, in the surfactant sodium lauryl sulfate solvent system³⁺Ions, having high applicability; in the presence of acetone: cd can be selectively identified in a solvent system with water being 1:9²⁺Ions.

Drawings

FIG. 1 is a 1X 10 dye probe prepared in example 1^-6The absorption spectrum of the 4mM sodium dodecyl sulfate solution at mol/L after reacting with different ions shows that after 10mM different ions are added dropwise (the volume ratio of the sodium dodecyl sulfate solution to the different ions is 100: 1, the influence of the added water on the original solvent system can be ignored), the absorbance change condition of the probe,

when 10mM Fe was added dropwise³⁺After the solution, the absorption value of the probe at 655nm is obviously reduced (curve l), the solution is changed from blue to colorless, and the probe has no particularly obvious change of absorbance at 655nm for other ions in a sodium dodecyl sulfate solution as a solvent (curves a to k), thereby showing that the probe has the Fe absorbance change in the system³⁺Selective recognition of the effects.

FIG. 2 is a 1X 10 dye probe prepared in example 1^-6The concentration of mol/L is in the ratio of acetone: absorption spectra after interaction with different ions in water 1:9 (volume ratio), shown in the figure, 1 × 10 was added dropwise^-6The absorbance change of the probe after the water solution of different ions of mol/L,

when added dropwise to 1X 10^-6mol/L Cd²⁺In the case of the solution, the wavelength of the probe is red-shifted (curve l), and the solution is changed from blue to purple; and the probe was prepared in acetone: no particularly significant change in absorbance for other ions in water-1: 9 solvent (curves a to k) shows that the probe is directed to Cd in this system²⁺The selective recognition function of (a) is,

(Note: in FIGS. 1 and 2, since Cd²⁺Ions or Fe³⁺The concentration of the ionized solution is small, in this case only Cd²⁺Ions or Fe³⁺The solutions of ions were all colorless transparent solutions).

FIGS. 3 and 4 are hydrogen contents of final products prepared in example 1 of the present invention, respectivelySpectrum and carbon spectrum, the specific analysis data is as follows:¹H NMR(400MHz,CDCl₃)δ:8.12-8.11(d,J＝4.0Hz,2H),7.70-7.68(m,1H),7.47-7.45(m,1H),7.37-7.26(m,3H),6.64-6.63(d,J＝4.0Hz,2H),6.21(s,1H),4.27-4.23(m,2H),3.36-3.32(m,4H),2.80(s,1H),2.47(s,1H),1.83-1.81(m,2H),1.61-1.55(m,4H),1.51-1.45(m,2H),1.38-1.33(m,4H),1.24-0.97(m,9H)；¹³C NMR(75MHz,CDCl₃)δ:186.58,183.15,181.82,170.09,164.98,150.31,140.37,130.19,129.36,127.90,126.28,125.77,122.77,122.45,120.89,119.26,112.94,111.53,88.69,50.84,47.13,29.95,29.73,29.55,21.50,20.31,20.21,20.16,13.98,13.74.

Detailed Description

Example 1

(1) Dissolving 3, 4-dihydroxy-3-cyclobutene-1, 2-dione (5g,43.5mmol) in sufficient toluene, adding thionyl chloride (10.4 g in total), adding 20uL of anhydrous DMF (dimethylformamide) when half of the amount is added, further dropwise adding thionyl chloride at room temperature (25 ℃, the same below), refluxing the mixture for 6 hours after the addition is completed, removing the solvent, dissolving the residue in hexane, storing in a refrigerator, separating pale yellow crystals,

(2) dissolving the pale yellow crystals of 3, 4-dichloro-3-cyclobutene-1, 2-dione (2g, 13.2mmol) obtained in step (1) and N, N-dibutylaniline (4.2g,13.24mmol) in 10mL of anhydrous toluene, refluxing at 80 ℃ for 6 hours, cooling and pouring the reaction mixture into ice water, separating the two phases, washing the organic layer with water (250mL), drying and separating the solvent by evaporation to obtain a solid,

(3) fully dispersing the solid obtained in the step (2) in a mixed solution consisting of pure acetic acid (20ml), 1mol/L hydrochloric acid (1ml) and water (20ml), refluxing at 100 ℃ for 2 hours, cooling to room temperature (25 ℃, the same below), filtering, washing, dissolving with diethyl ether, removing the solvent diethyl ether under reduced pressure to obtain the product 3- (4- (dibutylamino) phenyl) -4-hydroxycyclobut-3-ene-1, 2-dione (1.2g,3.9mmol),

(4) and (3) refluxing the product 3- (4- (dibutylamino) phenyl) -4-hydroxycyclobut-3-ene-1, 2-dione (0.9g,3mmol) obtained in the step (3) and 3-butyl-6-iodo-2-methyl-benzothiazole (0.1g,3mmol) in a toluene/n-butanol system with the volume ratio of 1:1 at 110 ℃, removing the solvent under reduced pressure, and performing column chromatography to obtain a final product, namely a blue solid.

Example 2

(1) Dissolving 3, 4-dihydroxy-3-cyclobutene-1, 2-dione (7.5g,65.25mmol) in sufficient toluene, adding thionyl chloride (15.6 g in total), adding 20uL of anhydrous DMF (dimethylformamide) when half of the amount is added, further dropwise adding thionyl chloride at room temperature, refluxing the mixture for 6 hours after the addition is completed, removing the solvent, dissolving the residue in hexane, storing in a refrigerator, separating pale yellow crystals,

(2) the pale yellow crystals of 3, 4-dichloro-3-cyclobutene-1, 2-dione (3g, 19.8mmol) obtained in step (1) and N, N-dibutylaniline (6.3g,19.86mmol) were dissolved in 10mL of anhydrous toluene, and after refluxing at 80 ℃ for 6 hours, the reaction was cooled and poured into ice water, the two phases were separated, the organic layer was washed with water (250mL), dried and the solvent was separated by evaporation to obtain a solid,

(3) fully dispersing the solid obtained in the step (2) in a mixed solution consisting of pure acetic acid (20ml), 1mol/L hydrochloric acid (1ml) and water (20ml), refluxing at 100 ℃ for 2 hours, cooling to room temperature, filtering, washing, dissolving with diethyl ether, removing the solvent diethyl ether under reduced pressure to obtain the product 3- (4- (dibutylamino) phenyl) -4-hydroxycyclobut-3-ene-1, 2-dione,

(4) and (3) refluxing the product 3- (4- (dibutylamino) phenyl) -4-hydroxycyclobut-3-ene-1, 2-dione (1.8g,6mmol) obtained in the step (3) and 3-butyl-6-iodo-2-methyl-benzothiazole (0.2g,6mmol) in a toluene and n-butanol system with the volume ratio of 1:1 at 110 ℃, removing the solvent under reduced pressure, and performing column chromatography to obtain a final product, namely a blue solid.

Comparative example 1

In contrast to example 1, the product of comparative example 1 was prepared without the conjugated structure of the substituted aniline:

diethyl squarate (3mmol) and 3-butyl-6-iodo-2-methyl-benzothiazole (1.0g,3mmol) were dissolved in 20mL of ethanol, heated at 80 ℃ for 6 hours, finally 5mL of triethylamine was added, heating was continued for 6 hours, the solvent was removed under reduced pressure, and the product of comparative example 1 was obtained by column chromatography.

The final product of this comparative example, which had a maximum absorption wavelength around 350nm in a 4mM aqueous solution of sodium lauryl sulfate (only one distinct absorption peak was observed in the pure probe without addition of complex ion, as shown in curve M in FIG. 1), was tested in the same manner as in FIG. 1, when 10mM Fe was added dropwise³⁺In the case of the solution, the decrease in the absorption value of the probe at 350nm was similar to that in the case of dropping a metal ion such as copper or cobalt, and the result did not show that the probe substance had Fe³⁺Selectivity of (a);

in the presence of acetone: the final product of this comparative example, which had a maximum absorption wavelength of about 280nm in a solvent of 1:9 (volume ratio) of water, was subjected to the same test as that shown in FIG. 2, while 10mM of Cd was added dropwise²⁺In the case of a solution, the decrease of the absorption value of the probe at 280nm is similar to that in the case of dropwise adding metal ions such as copper, zinc and the like, and the result does not show that the probe substance is used for Cd²⁺Selectivity of (2).

Comparative example 2

The product (1mmol) obtained in step (4) of example 1 was dissolved in 15mL of ethanol, Pd/C catalyst (0.2mmol) was added, and the reaction was continued for 12 hours with bubbling of hydrogen gas to displace air, reducing the carbon-carbon double bond in the probe product, filtering to remove the solid, and the filtrate was separated and purified by column chromatography to give the probe product of comparative example 2.

The final product of this comparative example was subjected to the test in the same manner as in FIG. 1, in a 4mM aqueous solution of sodium lauryl sulfate having a maximum absorption wavelength of about 450nm, while 10mM Fe was added dropwise³⁺In the case of the solution, the decrease in the absorbance of the probe at 450nm was similar to that in the case of dropping a metal ion such as copper or cobalt, and the result did not show that the probe substance had Fe³⁺Selectivity of (a);

in the presence of acetone: water 1:9 (volume ratio) as a solvent, the maximum absorption wavelength of the final product of this comparative example was 280nm, and the product was subjected to the test in the same manner as in FIG. 2, while 10mM of Cd was added dropwise²⁺The absorption value of the probe at 280nm is reduced in the case of solution, and the absorption value is reduced in the case of dropwise adding metal ions such as copper and zincSimilarly, the results do not show that the probe substance is directed to Cd²⁺Selectivity of (2).

Claims

1. The application of the asymmetric squaraine dye probe based on the substituted aniline is characterized in that: the chemical structure of the probe is that,

；

the dye probe with the molecular structure selectively recognizes Cd in different solvents respectively²⁺Or Fe³⁺；

Wherein Fe can be identified in a surfactant sodium dodecyl sulfate solvent system³⁺Ions;

in the presence of acetone: cd can be selectively identified in a solvent system with the water volume ratio of 1:9²⁺Ions.