Boron-containing nitrogen-containing phenothiazine discoloring material and application thereof in fluoride ion detection
By preparing boron-containing phenthiazine mechanochromic materials, the problems of low exciton utilization and narrow color change range in existing technologies have been solved, achieving high-contrast color changes and fluoride ion detection, which can be applied to information storage, reversible writing media, sensing and anti-counterfeiting fields.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-02-09
- Publication Date
- 2026-03-24
AI Technical Summary
Existing mechanochromic materials have low exciton utilization and a narrow color-changing range, making it difficult to meet the application requirements for high contrast.
Boron-nitrogen phenthiazide mechanochromic materials were prepared, and high-contrast color-changing materials were synthesized under specific reaction conditions and applied to fluoride ion detection.
It achieves high-contrast color changes and fluorescence response, and can effectively detect fluoride ions, making it applicable to information storage, reversible writing media, sensing, and anti-counterfeiting fields.
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Figure CN116284077B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of mechanochromic materials, in particular to a kind of boron-containing nitrogen phenothiazine mechanochromic material and preparation method thereof. BACKGROUND
[0002] The development and utilization of main group elements have always been favored by many scientific researchers, especially mechanochromic fluorescent (MCL) materials, which have aroused the research enthusiasm of the scientific community due to their unique stimulus response properties and are widely used in many fields. Mechanochromic fluorescent materials generally change optical intensity and color significantly under external stimuli such as force, heat, steam, and acid-base properties. Based on this phenomenon, mechanochromic fluorescent materials have been used in information storage, reversible writing media, sensing, and anti-counterfeiting, and have shown potential commercial value. Although mechanochromic materials have made significant progress in the short term, many mechanochromic materials, especially organic mechanochromic fluorescent materials, are limited by low exciton utilization and narrow material color change range. Based on this problem, it is of great significance to explore mechanochromic fluorescent materials with high exciton utilization and high contrast. SUMMARY
[0003] In order to overcome the shortcomings of the prior art, the present application provides a kind of boron-containing nitrogen phenothiazine mechanochromic material and preparation method thereof. The obtained material has high contrast in mechanofluorochromic performance color change, and the boron electron-deficient property can be applied to fluoride ion detection.
[0004] The present application provides a kind of boron-containing nitrogen phenothiazine mechanochromic material, and the structure general formula of the material is:
[0005]
[0006] Among them, R=Ar, I, Br, Cl, The preparation method of the mechanochromic material is as follows: a phenothiazine derivative substituted at positions 3,7 is dissolved in THF solution, the reaction system is placed at-70 to-80 DEG C, n-butyllithium is slowly added under nitrogen protection, after the addition is completed, stirring is continued at-70 to-80 DEG C for 30 minutes, and then dimethyl boron fluoride tetrahydrofuran solution is slowly added to the above system, the temperature is kept at-70 to-80 DEG C, and stirring is continued for half an hour, slowly warmed to room temperature, and the reaction is continued for 12 hours, the solvent is removed under reduced pressure, and boron-containing nitrogen phenothiazine mechanochromic material is obtained by silica gel chromatography column.
[0007] Preferably, the amount of THF is 10 ml THF per mmol of phenothiazine derivative.
[0008] Preferably, the molar ratio of the phenothiazine derivative to dimethyl boron fluoride is 1:1.04.
[0009] Preferably, the molar ratio of the phenothiazine derivative to n-butyllithium is 1:1.04;
[0010] Preferably, the eluent for the silica gel chromatography column is petroleum ether:ethyl acetate, with a volume ratio of 5:1.
[0011] Preferably, the THF should be prepared by evaporating and drying pure sodium metal.
[0012] Preferably, the substituent R in the mechanochromic material is Or phenyl.
[0013] Preferably, the substituent R is The metronidazole derivative of the chromogenic material was prepared as follows: Pinnacol ester, 3,7-dibromophenothiazine, and potassium acetate were added to a reaction vessel, followed by the addition of dried N,N-dimethylacetamide solvent. The system was then replaced with a nitrogen atmosphere. Under nitrogen-filled conditions, [1,1'-1-bis(triphenylphosphine)ferrocene]palladium dichloride was rapidly added to the three-necked round-bottom flask. The reaction temperature was set to 80°C, and the reaction time was 3 hours. After the reaction was complete, the mixture was quenched with water and then extracted with dichloromethane. The solvent was removed from the extract under reduced pressure, and the product was purified by silica gel chromatography. The molar ratio of pinnacol ester to 3,7-dibromophenothiazine was 1:2.2.
[0014] Preferably, the mechanochromic material with substituent R being phenyl, and the corresponding phenothiazine derivative is prepared as follows: 3,7-dibromophenothiazine is dissolved in a mixed solution of ethylene glycol ethyl ether and water, deoxygenated with nitrogen, refluxed at 130°C for 5 minutes, then phenylboronic acid, K2CO3 and Pd(PPh3)4 are rapidly added, refluxed at 130°C for 15 minutes, cooled to room temperature, and 100 mL of water is added. The mixture is filtered, washed successively with large amounts of water, ethanol and acetone, and dried to obtain the product. The molar ratio of 3,7-dibromophenothiazine:phenylboronic acid:K2CO3 is 1:2.8:5.6, the amount of Pd(PPh3)4 is 1.73%, the volume ratio of ethylene glycol ethyl ether to water is 10:1, and the solvent volume per mmol of 3,7-dibromophenothiazine is 11 mL.
[0015] This invention provides an application of a boron-nitrogen phenothiazine mechanochromic material. After grinding, the material produces color and fluorescence changes as well as stable boron-nitrogen units. This material can be applied in the fields of information storage, reversible writing media, sensing, and anti-counterfeiting.
[0016] The mechanochromic material with substituent R being phenyl can be prepared as a fluorescent probe and used as a fluoride ion detection reagent, including the following steps:
[0017] 1) Dissolve boron-containing nitrogen-containing phenothiazine E in tetrahydrofuran to prepare 1×10 -3M's stock solution;
[0018] 2) Add 4950 μL of tetrahydrofuran to every 50 μL of stock solution and let stand at room temperature for 2 hours to prepare the fluorescent probe.
[0019] The beneficial effects of this invention are as follows: This invention provides a class of functionalized boron-substituted phenothiazine small molecules. In the process of implementation, this invention also provides the material with light-emitting device performance, exhibiting high-contrast color changes under the action of external force, with a maximum spectral shift of 106 nm. In addition, based on the electron-deficient property of boron atoms, this material can be applied to fluoride ion detection, with good detection effect. Attached Figure Description
[0020] Figure 1 The graph shows the color change of the compound prepared in Example 1 under 365nm fluorescence and 365nm fluorescence after grinding.
[0021] Figure 2 The fluorescence emission spectra of the compound prepared in Example 1 before and after grinding are shown.
[0022] Figure 3 The graph shows the color change of the compound prepared in Example 2 under 365nm fluorescence and 365nm fluorescence after grinding.
[0023] Figure 4 The fluorescence emission spectra of the compound prepared in Example 2 before and after grinding are shown.
[0024] Figure 5 The 1H NMR spectrum of the compound prepared in Example 1;
[0025] Figure 6 The carbon NMR spectrum of the compound prepared in Example 1;
[0026] Figure 7 The 1H NMR spectrum of the compound prepared in Example 2;
[0027] Figure 8 The carbon NMR spectrum of the compound prepared in Example 2;
[0028] Figure 9 The image shows the UV spectrum of the response of the compound prepared in Example 2 to fluoride ions;
[0029] Figure 10 The fluorescence spectrum of the compound prepared in Example 2 in response to fluoride ions;
[0030] Figure 11 The image shows the UV spectrum of the response of the compound prepared in Example 2 to fluoride ions;
[0031] Figure 12 The image shows the fluorescence response of the compound prepared in Example 2 to fluoride ions. Detailed Implementation
[0032] Example 1: This example provides a boron-containing phenthiazide mechanochromic material, whose general structural formula is:
[0033]
[0034] Its preparation method is as follows:
[0035] In a three-necked round-bottom flask, 1.774 g (5 mmol) of piphenazine ester, 2.79 g (11 mmol) of dibromophenthiazide, and 1.85 g of potassium acetate were added. Then, dried N,N-dimethylacetamide solvent was added, and the system was replaced with a nitrogen atmosphere. Under nitrogen-filled conditions, 15 mg of [1,1'-1-bis(triphenylphosphine)ferrocene]palladium dichloride was rapidly added to the three-necked round-bottom flask. The reaction temperature was set to 80 °C, and the reaction time was 3 h. After the reaction was completed, water was added to quench the reaction, and then the mixture was extracted with dichloromethane. The solvent was removed from the extract phase under reduced pressure, and the mixture was purified by silica gel column chromatography to obtain compound A.
[0036]
[0037] Compound A (2.19 g, 5 mmol) was dissolved in 50 mL of tetrahydrofuran distilled from sodium metal. The system was then purged under nitrogen atmosphere, and the reaction mixture was placed at -80 °C. Under nitrogen protection, n-butyllithium (2.1 mL, 5.2 mmol, 2.5 M) was slowly added dropwise over 0.5 h. After the addition was complete, the mixture was stirred at -80 °C for 30 min. Then, compound B (1.4 g, 5.2 mmol) was dissolved in 10 mL of tetrahydrofuran distilled from sodium metal and slowly added dropwise to the above solution. The temperature was maintained at -80 °C and the mixture was stirred for another 30 min. The temperature was then slowly raised to room temperature and stirred for another 12 h. After the reaction was complete, compound C was obtained by silica gel chromatography with petroleum ether:ethyl acetate (5:1) as the eluent.
[0038]
[0039] The solid-state fluorescence emission spectrum of compound C shows an emission peak at 500 nm. Under 365 nm UV light irradiation, the fluorescence color is blue-green. When the solid powder is placed in a mortar and ground for 2 minutes, then uniformly coated onto a quartz plate, the fluorescence emission peak is measured at 545 nm. Under 365 nm UV light irradiation, the fluorescence color is yellow-green. The fluorescence emission peak red-shifts by 45 nm after grinding, achieving a high-contrast color change under external force. Figure 1 , Figure 2 .
[0040] Example 2: This example provides a boron-nitrogen-containing phenthiazide mechanochromic material, whose general structural formula is:
[0041]
[0042] Its preparation method is as follows:
[0043] Compound 3,7-dibromophenthiazide (3.57 g, 10.0 mmol) was dissolved in a mixture of ethylene glycol ether and water (10:1, 110 mL), deoxygenated with nitrogen, and refluxed at 130 °C for 5 minutes. Then, phenylboronic acid (3.42 g, 28.0 mmol, 2.80 equivalents), K₂CO₃ (7.73 g, 56.0 mmol, 5.60 equivalents) and Pd(PPh₃)₄ (200 mg, 0.17 mmol, 1.73 mol%) were rapidly added, and the mixture was refluxed at 130 °C for 15 minutes. After cooling to room temperature, 100 mL of water was added, and the mixture was filtered. The solution was washed successively with large amounts of water, ethanol (100 mL), and acetone (3-30 mL), and dried to obtain compound D.
[0044]
[0045] Compound D (1.76 g, 5 mmol) was dissolved in 50 mL of tetrahydrofuran purified by distillation with metallic sodium. The system was then purged under nitrogen atmosphere, and the reaction mixture was placed at -80 °C. Under nitrogen protection, n-butyllithium (2.1 mL, 5.2 mmol, 2.5 M) was slowly added dropwise over 0.5 h. After the addition was complete, the mixture was stirred at -80 °C for 30 min. Then, compound B (1.4 g, 5.2 mmol) was dissolved in 10 mL of tetrahydrofuran purified by distillation with metallic sodium and slowly added dropwise to the above solution. The temperature was maintained at -80 °C and the mixture was stirred for another 30 min. The temperature was then slowly raised to room temperature and stirred for another 12 h. After the reaction was complete, compound E was obtained by silica gel chromatography with petroleum ether:ethyl acetate (5:1) as the eluent.
[0046]
[0047] The solid-state fluorescence emission spectrum of compound E shows an emission peak at 461 nm. Under 365 nm UV light irradiation, the fluorescence color is blue. When the solid powder is placed in a mortar and ground for 2 minutes, then uniformly coated onto a quartz plate, the fluorescence emission peak is measured at 567 nm. Under 365 nm UV light irradiation, the fluorescence color is yellow. The fluorescence emission peak red-shifts by 106 nm after grinding, achieving a high-contrast color change under external force. Figure 3 , Figure 4 As shown.
[0048] To verify the effectiveness of the present invention, the detection of fluoride ions by the boronazine phenothiazine E synthesized in Example 2 was investigated, as shown in the figure.
[0049] inFigure 9 , Figure 10 The images show the UV-Vis absorption and fluorescence spectra of the synthesized compound E. Figure 9 The UV-Vis absorption spectrum clearly shows that with the addition of fluoride ions, the absorption peak at 269 nm gradually red-shifts to 285 nm, while a new absorption peak appears at 344 nm, with its absorbance gradually increasing with the addition of fluoride ions; simultaneously, this is also evident in the fluorescence spectrum. Figure 10 The emission peak at 463 nm was clearly observed to gradually increase. When the amount of fluoride ions added reached 25 μM, the fluorescence color of the solution changed from almost no emission to a distinct blue color.
[0050] When the fluoride ion concentration is higher than 25 μM, such as Figure 11 , Figure 12 As shown, the maximum absorption peak at 344 nm in the ultraviolet spectrum gradually redshifts to 418 nm; in the fluorescence spectrum... Figure 12 It can be clearly seen that the emission peak at 463 nm gradually decreases, while a new emission peak appears at 566 nm. As the concentration of fluoride ions increases, this emission peak also gradually strengthens, and the fluorescence color of the solution changes from blue to yellow-green.
[0051] Therefore, the prepared boronazine phenothiazine fluorescent probe can effectively detect different amounts of fluoride ions through changes in ultraviolet and fluorescence spectra and color. When the fluoride ion concentration is less than 25 μM, the absorption peak at 344 nm in the ultraviolet absorption spectrum is enhanced, the emission peak at 463 nm in the fluorescence is enhanced, and the fluorescence of the solution changes from almost no emission to a bright blue visible to the naked eye. When the fluoride ion concentration is higher than 25 μM, the ultraviolet absorption spectrum redshifts to 418 nm, the fluorescence emission spectrum redshifts to 566 nm, and the fluorescence color changes from blue to yellow-green, which can realize the visual colorimetric detection of fluoride ions of different concentrations.
[0052] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.
Claims
1. A boron-containing phenthiazine mechanochromic material, characterized in that, The structural formula of this material is: ； Wherein, R is a phenyl or .
2. The method for preparing a boron-containing nitrogen-containing phenothiazine mechanochromic material according to claim 1, characterized in that, Replace the phenyl group at the 3,7 position or at the 3,7 position The substituted phenothiazine derivative was dissolved in THF solution. The reaction system was placed at -70 to -80°C, and n-butyllithium was slowly added dropwise under nitrogen protection. After the addition was complete, the mixture was stirred at -70 to -80°C for 30 minutes. Then, a tetrahydrofuran solution of dimethyl boron fluoride was slowly added dropwise to the above system. The temperature was maintained at -70 to -80°C and the mixture was stirred for another half hour. The temperature was then slowly raised to room temperature and the reaction was continued for 12 hours. The solvent was removed under reduced pressure, and the boron-nitrogen phenothiazine mechanochromic material was obtained by silica gel chromatography.
3. The method for preparing a boron-containing nitrogen-containing phenothiazine mechanochromic material according to claim 2, characterized in that, The THF dosage is 10 ml THF / mmol phenothiazine derivative; the molar ratio of the phenothiazine derivative to dimethyl boron fluoride is 1:1.
04.
4. The method for preparing a boron-containing nitrogen-containing phenothiazine mechanochromic material according to claim 3, characterized in that, The molar ratio of the phenothiazine derivative to n-butyllithium is 1:1.
04.
5. The method for preparing a boron-containing nitrogen-containing phenothiazine mechanochromic material according to claim 4, characterized in that, The eluent for the silica gel chromatography column is petroleum ether: ethyl acetate, with a volume ratio of 5:
1.
6. The method for preparing a boron-containing nitrogen-containing phenothiazine mechanochromic material according to claim 2, characterized in that, The substituent R is The preparation method of the corresponding phenothiazine derivative is as follows: Pinnatrol ester, 3,7-dibromophenothiazine, and potassium acetate are added to a reaction vessel, followed by the addition of dried N,N-dimethylacetamide solvent. The system is then replaced with a nitrogen atmosphere. Under nitrogen-filled conditions, [1,1'-1-bis(triphenylphosphine)ferrocene]palladium dichloride is rapidly added to the reaction vessel. The reaction temperature is set to 80°C, and the reaction time is 3 hours. After the reaction is complete, the mixture is quenched with water and then extracted with dichloromethane. The solvent is removed from the extract phase under reduced pressure, and the mixture is purified by silica gel chromatography. The molar ratio of pinnatrol ester to 3,7-dibromophenothiazine is 1:2.
2.
7. The method for preparing a boron-containing nitrogen-containing phenothiazine mechanochromic material according to claim 2, characterized in that, The substituent R is phenyl, and the corresponding phenothiazine derivative is prepared as follows: 3,7-dibromophenothiazine is dissolved in a mixed solution of ethylene glycol ethyl ether and water, deoxygenated with nitrogen, refluxed at 130°C for 5 minutes, then phenylboronic acid, K2CO3 and Pd(PPh3)4 are rapidly added, refluxed at 130°C for 15 minutes, cooled to room temperature, 100 mL of water is added, filtered, and washed successively with large amounts of water, ethanol and acetone, and dried to obtain the product.
8. The application of the boron-containing phenthiazine mechanochromic material according to claim 1, characterized in that, After grinding, the material produces color and fluorescence changes as well as stable boron-nitrogen units. The application is in the fields of information storage, reversible writing media, sensing and anti-counterfeiting.
9. The application of a boron-containing nitrogen-containing phenthiazine mechanochromic material, characterized in that, The structure of the aforementioned mechanochromic material is as follows: ； The application is to prepare a fluorescent probe as a fluoride ion detection reagent, and the detection method includes the following steps: 1) The mechanochromic material was dissolved in tetrahydrofuran to prepare a 1×10⁻⁶ solution. -3 M's stock solution; 2) Add 4950 μL of tetrahydrofuran to every 50 μL of stock solution and let stand at room temperature for 2 hours to prepare the fluorescent probe.