Cyanostilbene derivative, preparation method thereof and application of cyanostilbene derivative in iodide ion detection

Abstract

The invention discloses a cyano-stilbene derivative, a preparation method thereof and application of the cyano-stilbene derivative in iodide ion detection, and relates to the technical field of organic synthesis and analytical chemistry, the cyano-stilbene derivative is called TPA-Cyn-PhC for short, and the structural formula of the cyano-stilbene derivative is as follows: # imgabs0 #. The probe can be used for sensitive detection of iodide ions in the environment, is not interfered by other ions, has the lowest detection limit of 3.67 * 10 <-7 > mol / L, and is extremely suitable for detection of trace and trace iodide ions.

Description

Technical Field

[0001] The present invention relates to the technical fields of organic synthesis and analytical chemistry, and particularly relates to a cyano-distyrene derivative, a preparation method thereof, and an application thereof in the detection of iodide ions. Background Art

[0002] In recent years, as anions have occupied an important position in the fields of biomedicine, chemistry, environment, etc., the research enthusiasm based on anion detection has been continuously rising. Among them, iodide ion, as an important anion, plays a crucial role in both the ecological environment and life processes. Iodine in nature mainly exists in the form of iodide, and both iodine deficiency and excess will affect the normal growth and development of the ecosystem balance (such as environmental pollution, loss of biodiversity) and living organisms (such as thyroid function problems, autoimmune diseases, canceration). Therefore, the detection of iodide ions is crucial in the fields of environment and life science. At the same time, there is an urgent need to construct a highly sensitive, highly selective, low-cost and easy-to-use fluorescent probe for iodide ion detection, which has very important practical significance and application value.

[0003] After an organic fluorescent probe interacts with a specific guest ion or molecule, it will produce a significant fluorescence change, which has the obvious advantages of simple operation, high sensitivity and low cost, and has now been widely used in the sensing and detection of various anions, cations and biomolecules. However, most traditional fluorescent probes have high fluorescence in organic solvents, but fluorescence quenching (ACQ) occurs due to aggregation in poor solvents with high water content, which severely limits their practical applications. The aggregation-induced emission (AIE) molecules reported by the Tang Benzhong research group in 2001 effectively eliminated the ACQ phenomenon. Chemical functional group modification of the AIE fluorescent probe skeleton can specifically and highly sensitively recognize substrates. Cyano-distyrene is an AIE fluorescent molecule that has attracted much attention in recent years. It has the characteristics of stable structure, high fluorescence intensity, good environmental adaptability stability, etc., and shows good application prospects in the fields of ion detection, biomolecular probes, etc. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a cyano-distyrene derivative, a preparation method thereof, and an application thereof in the detection of iodide ions. The presence of iodide ions can be highly sensitively and selectively detected through a relatively typical fluorescence quenching phenomenon, which has good practical application prospects.

[0005] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0006] One of the purposes of the present invention is to provide a cyano-distyrene derivative, the chemical name of which is (4-(1-cyano-2-(4-(diphenylamino)phenyl)vinyl)phenyl)-phenyl thiocarbonate, abbreviated as TPA-Cyn-PhC, and its structural formula is as follows:

[0007]

[0008] A second object of the present invention is to provide a method for preparing the aforementioned cyano-diphenyl ethylene derivative, comprising the following steps:

[0009] (1) 4-Diphenylamino benzaldehyde and p-hydroxy phenylacetonitrile undergo a Knoevenagel condensation reaction to obtain an intermediate (abbreviated as TPA-Cyn);

[0010]

[0011] (2) TPA-Cyn and phenyl chloroformate undergo a substitution reaction to obtain TPA-Cyn-PhC.

[0012]

[0013] In step (1), the molar ratio of the 4-diphenylamino benzaldehyde to the p-hydroxy phenylacetonitrile is 1:(1.2 - 4.5), preferably 1:(1.2 - 2). An excessive amount of p-hydroxy phenylacetonitrile can increase the conversion rate of 4-diphenylamino benzaldehyde, thereby increasing the yield of TPA-Cyn. However, an excessive amount of p-hydroxy phenylacetonitrile will increase the cost and the purification difficulty of TPA-Cyn. Therefore, it is necessary to reasonably control the amount of p-hydroxy phenylacetonitrile used.

[0014] In step (1), the Knoevenagel condensation reaction is carried out under the catalytic action of a base. The base is an inorganic base or an organic base. The inorganic base includes but is not limited to at least one of sodium hydroxide, potassium hydroxide, magnesium hydroxide, sodium carbonate, calcium hydroxide; the organic base includes but is not limited to at least one of piperidine, pyridine, triethylamine, potassium tert-butoxide; the amount of the base used is 5 - 15 times the mass of the p-hydroxy phenylacetonitrile.

[0015] In step (1), the reaction solvent for the Knoevenagel condensation reaction is a commonly used organic solvent in the art, including but not limited to at least one of ethanol, tetrahydrofuran, methanol, 1,4-epoxyhexane, acetonitrile, or other solvents that can dissolve 4-diphenylamino benzaldehyde and p-hydroxy phenylacetonitrile and will not react with them.

[0016] In step (1), the reaction temperature of the Knoevenagel condensation reaction is 50 - 95 °C, and the reaction time is 10 - 16 h. The reaction time can be appropriately adjusted according to the feed amount. An excessively long reaction time will increase the energy consumption.

[0017] In step (2), the molar ratio of TPA-Cyn to phenyl thiocarbonochloridate is 1:(1.2 - 4), preferably 1:(1.2 - 1.5). An appropriately excessive amount of phenyl thiocarbonochloridate can make the reaction of TPA-Cyn complete as much as possible, thereby improving the yield of TPA-Cyn-PhC.

[0018] In step (2), the substitution reaction is carried out in the presence of an acid-binding agent, and the acid-binding agent includes but is not limited to at least one of potassium carbonate, potassium iodide, potassium bromide, sodium iodide, sodium carbonate, sodium acetate, pyridine, and triethylamine. The acid-binding agent promotes the forward progress of the substitution reaction by neutralizing the hydrogen chloride generated in the substitution reaction, accelerating the reaction rate, shortening the reaction time, and improving the yield of TPA-Cyn-PhC.

[0019] In step (2), the reaction solvent for the substitution reaction is an organic solvent commonly used in the art, including but not limited to at least one of acetonitrile, tetrahydrofuran, methanol, ethanol, and 1,4-epoxyhexane. Other solvents that can dissolve TPA-Cyn and phenyl thiocarbonochloridate and do not react with them can also be used.

[0020] In step (2), the reaction temperature of the substitution reaction is 90 - 150 °C, and the reaction time is 10 - 20 h. If the reaction temperature is too low, the reaction time is long and the raw material conversion rate is low; if the reaction temperature is too high, although the reaction time can be shortened, it will lead to the generation of by-products and reduce the yield of the target product.

[0021] The third object of the present invention is to provide the use of the aforementioned cyanostilbene derivative as an AIE fluorescent probe.

[0022] The fourth object of the present invention is to provide the application of the aforementioned cyanostilbene derivative in the detection of iodide ions. Specifically, an iodide ion detection reagent is prepared using the aforementioned cyanostilbene derivative.

[0023] The beneficial effects of the present invention are as follows:

[0024] (1) When used for detecting iodide ions, the TPA-Cyn-PhC provided by the present invention can make the detection result visualizable. Its tetrahydrofuran solution has a weak fluorescence emission at 500 nm; its mixed solution of tetrahydrofuran and water (with a water volume fraction of 95%) emits strong fluorescence at 565 nm, and the fluorescence quantum yield is as high as 0.59. The TPA-Cyn-PhC in the solution forms a 1:1 complex with iodide ions, and then a significant fluorescence quenching phenomenon occurs, which can be used for the sensitive detection of iodide ions in the environment and is not interfered by other ions. It is an ideal rapid detection sensor for iodide ions and has practical application value in production and life.

[0025] (2) The TPA-Cyn-PhC provided by the present invention has high selectivity for the detection of iodide ions, with a minimum detection limit of 3.67×10 -7 mol / L, and shows a good linear quantitative relationship in the range of 0 - 5 μmol / L. It has high efficiency in practical applications and is extremely suitable for the detection of trace and ultra-trace iodide ions.

[0026] (3) The preparation method of the TPA-Cyn-PhC provided by the present invention can prepare a variety of novel fluorescent probes by selectively replacing the reaction raw materials, and has good universality.

[0027] (4) The preparation method of the TPA-Cyn-PhC provided by the present invention meets the requirements of industrial green production, is easy to operate, has mild conditions, high yield, and has broad development prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 1H NMR spectrum of the TPA-Cyn-PhC prepared in Example 1;

[0029] Figure 2 13C NMR spectrum of the TPA-Cyn-PhC prepared in Example 1;

[0030] Figure 3 Mass spectrum of the TPA-Cyn-PhC prepared in Example 1;

[0031] Figure 4 Fluorescence spectrum of the TPA-Cyn-PhC prepared in Example 1 in THF / H 2 O mixed solvents with different water contents;

[0032] Figure 5 Selectivity test results of the TPA-Cyn-PhC prepared in Example 1;

[0033] Figure 6 Anti-interference test results of the TPA-Cyn-PhC prepared in Example 1;

[0034] Figure 7 Fluorescence spectra of the TPA-Cyn-PhC prepared in Example 1 when detecting iodide ion solutions with different concentrations;

[0035] Figure 8 Linear relationship between the fluorescence intensity and the iodide ion concentration of the TPA-Cyn-PhC prepared in Example 1 when detecting iodide ion solutions with different concentrations. DETAILED DESCRIPTION OF THE INVENTION

[0036] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below in conjunction with specific examples and drawings.

[0037] Abbreviations in the following examples:

[0038] THF: Tetrahydrofuran;

[0039] H 2 O: Water;

[0040] NaOH: Sodium hydroxide;

[0041] I - : Iodide ion;

[0042] HCO 3- : Bicarbonate;

[0043] CO 3 2- : Carbonate;

[0044] NO 3- : Nitrate;

[0045] F - : Fluoride ion;

[0046] Br - : Bromide ion;

[0047] CH 3 COO - : Acetate;

[0048] SO 4 2- : Sulfate;

[0049] ClO - : Hypochlorite;

[0050] HSO 3- : Bisulfite.

[0051] Example 1

[0052] Preparation of TPA-Cyn-PhC:

[0053] (1) Add 4-diphenylaminobenzaldehyde (5.4 g, 0.02 mol), p-hydroxybenzyl cyanide (3.9 g, 0.03 mol) and 25 mL of saturated NaOH solution to 120 mL of ethanol. Heat the resulting mixed solution to 70 °C and stir for 7 h. After the reaction is completed, cool the reaction solution to room temperature, add 50 mL of dilute hydrochloric acid (1 mol / L), then extract with dichloromethane. Concentrate the organic layer by rotary evaporation and recrystallize with methanol and water. Filter and dry the solid under vacuum to obtain 6.2 g of TPA-Cyn.

[0054] (2) TPA-Cyn (7.76 g, 0.02 mol), phenyl thiocarbonate (5.16 g, 0.03 mol), potassium carbonate (16.6 g, 0.12 mol) and potassium iodide (0.83 g, 0.005 mol) were added to 150 mL of acetonitrile, and the temperature was raised to 90 °C and stirred for reaction for 15 h. After the reaction was completed, the reaction solution was cooled to room temperature, filtered, the filter residue was washed with water and dried under vacuum to obtain 8.5 g of TPA-Cyn-PhC.

[0055] 1 H NMR (600 MHz, CDCl 3 ) δ ppm 7.77 - 7.71 (m, 2H, ArH), 7.55 - 7.51 (m, 2H, ArH), 7.31 (dd, J = 8.6, 2.5 Hz, 6H, ArH), 7.26 (d, J = 2.4 Hz, 2H, ArH), 7.17 - 7.14 (m, 2H, ArH), 7.12 - 7.07 (m, 4H, ArH), 7.05 - 7.03 (m, 2H, ArH), 6.89 - 6.87 (m, 2H, ArH).

[0056] 13 C NMR (150 MHz, CDCl 3 ) δ ppm 158.6, 157.7, 153.8, 153.6, 149.6, 146.5, 146.3, 132.3, 131.9, 131.9, 131.6, 130.6, 130.4, 130.3, 130.2, 130.2, 130.1, 129.8, 127.5, 126.1, 125.8, 125.7, 125.2, 124.9, 123.7, 123.6, 123.1, 122.9, 122.2, 121.7, 120.2, 119.7, 119.2, 116.6, 115.7.

[0057] MALDI-TOF-MS (C 34 H 24 N 2 O 2 S) Calcd. for m / z = 524.1558, found: 563.3717

[0058] [M + K] + .

[0059] Example 2

[0060] Preparation of TPA-Cyn-PhC:

[0061] (1) 4-Diphenylaminobenzaldehyde (5.4 g, 0.02 mol), 4-hydroxybenzyl cyanide (7.9 g, 0.06 mol) and 25 mL of saturated NaOH solution were added to 120 mL of ethanol. The resulting mixed solution was heated to 70 °C and stirred for reaction for 7 h. After the reaction was completed, the reaction solution was cooled to room temperature, 50 mL of dilute hydrochloric acid (1 mol / L) was added, and then it was extracted with dichloromethane. The organic layer was concentrated by rotary evaporation, recrystallized with methanol and water, filtered, and the solid was dried under vacuum to obtain 5.9 g of TPA-Cyn.

[0062] (2) TPA-Cyn (7.76 g, 0.02 mol), phenyl chlorothionoformate (6.9 g, 0.04 mol), potassium carbonate (19.3 g, 0.14 mol) and potassium iodide (0.83 g, 0.005 mol) were added to 150 mL of acetonitrile. The temperature was raised to 100 °C and stirred for reaction for 16 h. After the reaction was completed, the reaction solution was cooled to room temperature, filtered, the filter residue was washed with water, and dried under vacuum to obtain 9.2 g of TPA-Cyn-PhC.

[0063] Example 3

[0064] Preparation of TPA-Cyn-PhC:

[0065] (1) 4-Diphenylaminobenzaldehyde (5.4 g, 0.02 mol), 4-hydroxybenzyl cyanide (5.3 g, 0.04 mol) and 25 mL of saturated NaOH solution were added to 120 mL of ethanol. The resulting mixed solution was heated to 70 °C and stirred for reaction for 7 h. After the reaction was completed, the reaction solution was cooled to room temperature, 50 mL of dilute hydrochloric acid (1 mol / L) was added, and then it was extracted with dichloromethane. The organic layer was concentrated by rotary evaporation, recrystallized with methanol and water, filtered, and the solid was dried under vacuum to obtain 16.5 g of TPA-Cyn.

[0066] (2) TPA-Cyn (7.76 g, 0.02 mol), phenyl chlorothionoformate (17.2 g, 0.10 mol), potassium carbonate (19.3 g, 0.14 mol) and potassium iodide (0.83 g, 0.005 mol) were added to 150 mL of acetonitrile. The temperature was raised to 100 °C and stirred for reaction for 16 h. After the reaction was completed, the reaction solution was cooled to room temperature, filtered, the filter residue was washed with water, and dried under vacuum to obtain 9.0 g of TPA-Cyn-PhC.

[0067] Example 4

[0068] Fluorescent detection of iodide ions by TPA-Cyn-PhC:

[0069] The TPA-Cyn-PhC prepared in Example 1 was dissolved in THF to prepare a solution with a concentration of 1×10 -3mol / L stock solution and dilute it to a concentration of 1×10 -5 mol / L, and obtain THF / H with a water content of 0-95 vol%. 2 O mixed system, and the fluorescence intensity of TPA-Cyn-PhC in the mixed system was tested at an excitation wavelength of 340 nm. Figure 4 It can be seen that the fluorescence intensity of TPA-Cyn-PhC increases rapidly with the increase of water content in the mixed system, which shows that TPA-Cyn-PhC shows a unique AIE effect.

[0070] Example 5

[0071] Selective testing of TPA-Cyn-PhC:

[0072] The concentration was 1×10 -5 mol / L TPA-Cyn-PhC in THF / H 2 O mixed system (water content 95vol%) was added with a concentration of 1×10 -5 mol / L anion solution (I - , HCO 3- , CO 3 2- 、NO 3- 、F - Br - , CH 3 COO - 、SO 4 2- , ClO - , HSO 3- ) to obtain a mixed solution. The luminescence intensity of TPA-Cyn-PhC in the mixed solution was measured at an excitation wavelength of 340 nm. Figure 5 It can be seen that the addition of iodide ions causes significant fluorescence quenching of TPA-Cyn-PhC, which indicates that TPA-Cyn-PhC has a specific response to iodide ions.

[0073] Example 6

[0074] TPA-Cyn-PhC immunity test:

[0075] At a concentration of 1×10 -5 mol / L TPA-Cyn-PhC in THF / H 2 O mixed system (water content of 95 vol%) was used as a blank control, and then an iodine ion aqueous solution with a concentration of 100 mmol / L was added to the mixed system, followed by the addition of other anions (HCO 3- , CO3 2- , NO 3- , F - , Br - , CH 3 COO - , SO 4 2- , ClO - , HSO 3- ) solution, the fluorescence intensities of the blank control, the mixed solution with only iodide ions added, and the mixed solution with both iodide ions and other anions added were measured at an excitation wavelength of 340 nm. After calculation, the difference in the maximum fluorescence quenching efficiency between the case with interfering ions added and the case without interfering ions added was 1.8%. It can be seen that when there are a large number of other anions in the solution, it does not affect the selective recognition of iodide ions by TPA-Cyn-PhCP. Figure 6 It can be seen that when there are a large number of other anions in the solution, it does not affect the selective recognition of iodide ions by TPA-Cyn-PhCP.

[0076] Example 7

[0077] Linear relationship between the fluorescence intensity of TPA-Cyn-PhC and the iodide ion concentration:

[0078] To a THF / H -5 O mixed system (with a water content of 95 vol%) of TPA-Cyn-PhC with a concentration of 1×10 2 mol / L, aqueous solutions of iodide ions with different concentrations (the iodide ion concentrations are 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.4, 1.6, 1.8, 3.0, 5.0 times the concentration of TPA-Cyn-PhC) were added to prepare mixed solutions with a gradient change in iodide ions. The fluorescence intensity of TPA-Cyn-PhC in the mixed solutions was measured at an excitation wavelength of 340 nm. It can be seen that iodide ions with different concentrations can all quench the fluorescence of TPA-Cyn-PhC to varying degrees, showing a good linear relationship, indicating that the iodide ion concentration can be quantitatively detected by the change in fluorescence intensity. It can be seen that a good linear relationship (R = 0.99767) is presented in the range of iodide ion concentration from 0 to 5 μmol / L, and the detection limit calculated using the 3σ IUPAC standard is 3.67×10 Figure 7 It can be seen that iodide ions with different concentrations can all quench the fluorescence of TPA-Cyn-PhC to varying degrees, showing a good linear relationship, indicating that the iodide ion concentration can be quantitatively detected by the change in fluorescence intensity. Figure 8 It can be seen that a good linear relationship (R = 0.99767) is presented in the range of iodide ion concentration from 0 to 5 μmol / L, and the detection limit calculated using the 3σ IUPAC standard is 3.67×10 -7 mol / L.

[0079] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A cyanostilbene derivative, chemically named (4-(1-cyano-2-(4-(diphenylamino)phenyl)vinyl)phenyl)-phenylthiocarbonate, referred to as TPA-Cyn-PhC, has the following structural formula:

2. A method for preparing a cyanostilbene derivative, characterized in that: The following steps are involved: (1) 4-Diphenylaminobenzaldehyde reacts with p-hydroxyphenylacetonitrile to undergo Knoevenagel condensation reaction to obtain TPA-Cyn; (2) TPA-Cyn undergoes a substitution reaction with phenylthiochloroformate to obtain TPA-Cyn-PhC; 3. The preparation method according to claim 2, characterized in that: The molar ratio of the 4-dianilinobenzaldehyde to p-hydroxyphenylacetonitrile is 1:(1.2-4.5), preferably 1:(1.2-2).

4. The preparation method according to claim 2, characterized in that: The Knoevenagel condensation reaction is carried out under the catalysis of a base; Preferably, the base is an inorganic base or an organic base; Preferably, the inorganic base is selected from at least one of sodium hydroxide, potassium hydroxide, magnesium hydroxide, sodium carbonate and calcium hydroxide; Preferably, the organic base is selected from at least one of piperidine, pyridine, triethylamine and potassium tert-butoxide; Preferably, the amount of the base used is 5 to 15 times the mass of p-hydroxyphenylacetonitrile.

5. The preparation method according to claim 2, characterized in that: The reaction solvent of the Knoevenagel condensation reaction is selected from at least one of tetrahydrofuran, methanol, ethanol, 1,4-epoxyhexadecane and acetonitrile; Preferably, the reaction temperature of the Knoevenagel condensation reaction is 50-95° C., and the reaction time is 10-16 h.

6. The preparation method according to claim 2, characterized in that: The molar ratio of TPA-Cyn to phenyl chlorothioformate is 1:(1.2-4), preferably 1:(1.2-1.5).

7. The preparation method according to claim 2, characterized in that: The substitution reaction is carried out in the presence of an acid-binding agent, and the acid-binding agent is selected from at least one of potassium carbonate, potassium iodide, potassium bromide, sodium iodide, sodium carbonate, sodium acetate, pyridine, and triethylamine.

8. The preparation method according to claim 2, characterized in that: The reaction solvent of the substitution reaction is selected from at least one of acetonitrile, tetrahydrofuran, methanol, ethanol, and 1,4-epoxyhexadecane; Preferably, the reaction temperature of the substitution reaction is 90-150° C., and the reaction time is 10-20 h.

9. Use of the cyanostilbene derivative according to claim 1 or the cyanostilbene derivative prepared by the preparation method according to any one of claims 2 to 8 as an AIE fluorescent probe.

10. Use of the cyanostilbene derivative according to claim 1 or the cyanostilbene derivative prepared by the preparation method according to any one of claims 2 to 8 in iodide ion detection.

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