A switchable acidichromic cyanodiphenyl ethylene compound, a preparation method and application thereof

Abstract

The application discloses a switch type acid discoloration cyanostilbene compound and a preparation method thereof, belongs to the preparation field of cyanostilbene compounds, and the cyanostilbene compound is an orange solid powder. The preparation method comprises the following steps: adding 4-(dimethylamino) isophthalaldehyde and anhydrous ethanol into a 250ml round-bottom flask, and then heating to fully dissolve the 4-(dimethylamino) isophthalaldehyde; adding 4-cyanophenylacetonitrile into the above solution, and after the 4-cyanophenylacetonitrile is fully dissolved, saturated potassium carbonate solution is added for catalysis, and the reaction is carried out at 75-80 DEG C for 1.5-2h, and then the reaction is tracked by using a thin layer chromatography method; after the reaction is completed, hot suction filtration is carried out, and then ethanol is used for elution, and finally, the cyanostilbene compound in the form of orange powder is obtained through drying. The method has the advantages of easy raw material, mild condition, rapid synthesis, green environmental protection, and the post-treatment avoids the loss of samples caused by extraction and column chromatography, and the yield is ensured.

Description

Technical Field

[0001] This invention belongs to the field of preparation technology of cyanobrythril compounds, specifically relating to a switch-type acid-induced color-changing cyanobrythril compound, its preparation method, and its applications. Background Technology

[0002] Stimulus-responsive materials are a class of smart materials that can recognize changes in the external environment and thus produce specific fluorescent responses. These materials are widely used in cell imaging, fluorescence sensing, fluorescence anti-counterfeiting and other fields.

[0003] Acid-induced color-changing materials have been extensively studied because they can respond to changes in pH. These materials generally contain units that can be protonated or deprotonated. Based on their fluorescence response, they can be divided into on / off type and switch type acid-induced color-changing materials. Among them, switch type acid-induced color-changing materials show superior application value in fluorescent anti-counterfeiting technology.

[0004] Currently, white light-emitting diodes (LEDs) are widely used in production and daily life due to their advantages such as energy saving, environmental friendliness, and high luminous efficiency. Organic phosphors are low in cost, have mild reactions, and produce less pollution, and can even overcome severe photon absorption phenomena. However, many organic light-emitting materials reported at present are difficult to achieve white light emission from a single component of all-organic material. They often require the preparation of multi-color phosphors to fabricate white LEDs, which undoubtedly increases the cost and stability of LEDs.

[0005] Therefore, in summary, the design and synthesis of small organic fluorescent compounds and the preparation of pure organic single-component white light-emitting diodes are of great significance. Summary of the Invention

[0006] The technical problem to be solved by this invention is to provide a switchable acid-induced color-changing cyanoblastane compound, its preparation method, and its application. The invention utilizes the cyanoblastane compound to prepare a single-component white light-emitting diode, which solves the technical problems of high cost and poor stability in the prior art of using organic light-emitting materials to make light-emitting diodes. At the same time, the cyanoblastane compound has great application value in fluorescent anti-counterfeiting technology.

[0007] To address the aforementioned technical problems, the present invention provides the following technical solutions.

[0008] A switch-type acid-induced color-changing cyanobrythril compound of the present invention has the following structure:

[0009] The present invention relates to the application of a switch-type acid-induced color-changing cyanobrythryl stilbene compound in the field of fluorescent anti-counterfeiting technology.

[0010] The present invention discloses a method for preparing a switch-type acid-induced color-changing cyanobetaine compound, comprising the following steps:

[0011] Step 1: Add 4-(dimethylamino)-m-phthalaldehyde and 20 mL of anhydrous ethanol to a 250 mL round-bottom flask, and then heat to fully dissolve 4-(dimethylamino)-m-phthalaldehyde.

[0012] Step 2: Add 4-cyanophenylacetonitrile to the above solution. After the 4-cyanophenylacetonitrile is fully dissolved, add saturated potassium carbonate solution for catalysis and reflux at 75-80℃ for 1.5-2 hours. The reaction is then monitored by thin-layer chromatography. The molar ratio of 4-(dimethylamino)-isophthalaldehyde to 4-cyanophenylacetonitrile is 1:2.1. Step 3: After the above reaction is complete, filter while hot and wash with ethanol. Finally, dry to obtain an orange powder of cyanostilbene compound.

[0013] As a further step of the present invention, the reflux reaction in step two is carried out at 75°C for 2 hours.

[0014] As a further step of the present invention, the tracking reaction in step two is a tracking reaction of thin-layer chromatography using PE:EA = 1:1 as the developing solvent.

[0015] The present invention discloses a white light-emitting diode using a switch-type acid-induced color-changing cyano-stilbene compound, which is prepared by the following method: 5-10g of silica gel is mixed with 20-40mg of cyano-stilbene compound and degassed in a vacuum, and then the mixture is cured on an InGaN blue light chip for 1-2h to obtain a light-emitting diode optical device.

[0016] Beneficial effects

[0017] (1) The present invention provides a method for preparing a switch-type acid-induced color-changing cyanostilbene compound. The method uses readily available raw materials, is mild under mild conditions, is rapid in synthesis, is green and environmentally friendly, and the post-processing avoids the loss of samples caused by extraction and column chromatography, thus ensuring the yield.

[0018] (2) The present invention provides a switch-type acid-induced color-changing cyanobrythril compound that can respond to acid to quench fluorescence, which can then be restored by alkali. This acid-base alternating stimulation process can be cycled at least three times. Based on this acid-base stimulation response property, fluorescent anti-counterfeiting technology can be designed, including security ink, acid test paper and pattern printing.

[0019] (3) The present invention provides a switch-type acid-induced color-changing cyanobrythril compound that has good fluorescence emission in both solution and solid powder, and can be used to prepare all-organic single-component white light-emitting diodes. Attached Figure Description

[0020] Figure 1The proton NMR spectrum of the compound obtained in Example 1;

[0021] Figure 2 Carbon NMR spectra of the compounds obtained in Example 1;

[0022] Figure 3 Fluorescence emission spectra of the compounds obtained in Example 1 in tetrahydrofuran and solid powder states;

[0023] Figure 4 Acid-base stimulation response fluorescence emission cycle diagram of the compound obtained in Example 1;

[0024] Figure 5 The 1H NMR spectrum of the compound obtained in Example 1 under acid-base stimulation.

[0025] Figure 6 An example diagram illustrating the application of the compound obtained in Example 1 in fluorescent anti-counterfeiting;

[0026] Figure 7 Electroluminescence spectrum and CIE1931 color coordinates of the light-emitting diode prepared from the compound obtained in Example 1. Detailed Implementation

[0027] The examples given below are specific descriptions of the present invention. It must be emphasized that the embodiments given below are merely further elaborations of the present invention and not a limitation on the scope of protection of the present invention. Any improvements or adjustments made by those skilled in the art during actual implementation based on the above-described invention, unless they are not changes in an essential sense, shall still fall within the scope of protection of the present invention.

[0028] Example 1

[0029] The preparation reaction of the cyanobetaine compound provided in this embodiment is as follows:

[0030]

[0031] Knoevenagel condensation:

[0032] Add 0.35 g (2.0 mmol) of 4-(dimethylamino)-m-phenylenedialdehyde and 20 mL of anhydrous ethanol to a 250 mL round-bottom flask. Heat to fully dissolve the 4-(dimethylamino)-m-phenylenedialdehyde. Then add 0.58 g (4.1 mmol) of 4-cyanophenylacetonitrile. After the 4-cyanophenylacetonitrile is fully dissolved, add 2 drops of saturated potassium carbonate solution as a catalyst. Reflux at 75-80 °C for 1.5-2 h. Specifically, in this embodiment, the reflux reaction is carried out at 75 °C for 2 h. The reaction is monitored by thin-layer chromatography. Specifically, in this embodiment, the monitoring reaction is carried out by thin-layer chromatography using PE:EA = 1:1 as the developing solvent.

[0033] After the above reaction was completed, the mixture was filtered while hot and washed with ethanol. Finally, it was dried to obtain the cyanostilbene compound in the form of an orange powder (0.69 g, yield 82%).

[0034] The cyanostilbene compound was characterized by 1H and 1C NMR spectra, as shown in the following figures. Figure 1 , Figure 2 The characterization data are as follows:

[0035] 1H NMR spectrum 1 H NMR (CDCl3, 600MHz, δin ppm):8.26(s,1H),7.90-7.83(m,2H),7.77(t,J=10.8Hz,4H),7.68-7.55(m,3H), 7.49(s,1H),7.18(d,J=8.5Hz,1H),7.02(d,J=8.1Hz,1H),2.95(d,J=6.7Hz,6H).

[0036] Carbon NMR 13 C NMR(CDCl3,151MHz,δin ppm):144.62,143.49,142.63,138.88,138.23,132.98,132.84,131.65,129.09, 126.43,126.36,126.20,118.26,117.60,112.80,112.33,107.81,44.59,43.90.

[0037] Taking the cyanobrythril compound prepared in Example 1 as an example, its stimulus-response fluorescence properties were studied, as follows:

[0038] (1) Sample processing

[0039] Solution sample preparation: The cyanobrythril compound was prepared into a solution using N,N-dimethylformamide as the solvent to form 10... - 3 A concentrated solution of mol / L was prepared by taking 50 μL of the concentrated solution and diluting it to 5 mL with an organic solvent such as acetonitrile or tetrahydrofuran to obtain 10 mol / L. -5 A dilute solution of mol / L; solid tests were performed directly using cyanobrythril compound solid powder.

[0040] The fluorescence emission wavelengths of the cyanobrythril compound in tetrahydrofuran solution and solid powder states were 550 nm and 575 nm, respectively. (See the results below.) Figure 3 .

[0041] (2) Acid-base response behavior of cyanobrythril compounds

[0042] Adding trifluoroacetic acid to a dilute acetonitrile solution of cyanostilbene resulted in a blue shift and fluorescence quenching of the emission wavelength. Specifically, the molar ratio of cyanostilbene to trifluoroacetic acid was 1:1.2. Further addition of excess triethylamine to the acidified solution restored the fluorescence and emission wavelengths. This alternating acid-base treatment exhibited fluorescence switching behavior that could be repeated more than three times. The results are shown in [Figure number missing]. Figure 4 .

[0043] Figure 5 This is a 1H NMR spectrum showing the changes during acid-base stimulation. The graph shows that after the addition of acid, the H atom on the -N(CH3)2 group of the molecule... N The chemical shift increases; after the addition of triethylamine, H N The fact that it recovered proves that the protonation and deprotonation of -N(CH3)2 occurred during this process.

[0044] (1) Fluorescent anti-counterfeiting based on cyanobostilbene compounds, results are shown in... Figure 6 .

[0045] Dissolve 3 mg of cyanostilbene compound in 5 mL of dichloromethane to obtain a mixed solution (safe ink). Use a cotton swab to apply the solution to filter paper and write words or patterns. After drying, the filter paper will have yellow writing and exhibit yellow fluorescence under ultraviolet light. Fumigate the writing with trifluoroacetic acid vapor for about half a minute; the writing on the filter paper will disappear under both sunlight and ultraviolet light, thus encrypting the information. Fumigate the filter paper again with triethylamine, and the writing will reappear, decrypting the information. This encryption / decryption process can be repeated multiple times.

[0046] Dissolve 3 mg of cyanobrythril compound in 5 mL of dichloromethane to obtain a mixed solution. Use a cotton swab to apply the solution evenly and quickly onto filter paper. After air drying, an acid test strip is obtained. Use a capillary tube to apply various solutions to the test strip. Acids can cause the test strip to fade, while alkalis and other inorganic salt solutions show no obvious changes.

[0047] Dissolve 3 mg of cyanostilbene compound in 5 mL of dichloromethane to obtain a mixed solution. Apply the solution evenly to filter paper with a cotton swab and let it air dry to obtain a yellow paper. Cover the paper with a mold with a cutout pattern and fumigate with trifluoroacetic acid. The cutout parts fade due to acid stimulation, thus achieving pattern printing.

[0048] (2) White light-emitting diodes based on cyanoblastane compounds

[0049] Mix 5-10g of silica gel with 20-40mg of cyanostilbene compound, degas the mixture in a vacuum, and then cure the mixture on an InGaN blue light chip for 1-2 hours to obtain a light-emitting diode optical device.

[0050] When a forward current of 25mA is applied, the light-emitting diode optical device exhibits warm white light, a correlated color temperature of 3293K, white light color coordinates of (0.3980, 0.3498), and a luminous efficacy of 33.77lm / W.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the invention without departing from the scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A switch-type acid-induced color-changing cyanostilbene compound, characterized in that, It has the following structure:

2. The application of the switch-type acid-induced color-changing cyanobrythril compound according to claim 1 in the field of fluorescent anti-counterfeiting technology.

3. A method for preparing the switch-type acid-induced color-changing cyanostilbene compound according to claim 1, characterized in that, The steps are as follows: Step 1: Add 4-(dimethylamino)-m-phthalaldehyde and 20 mL of anhydrous ethanol to a 250 mL round-bottom flask, and then heat to fully dissolve 4-(dimethylamino)-m-phthalaldehyde. Step 2: Add 4-cyanophenylacetonitrile to the above solution. After the 4-cyanophenylacetonitrile is fully dissolved, add saturated potassium carbonate solution for catalysis and reflux at 75-80℃ for 1.5-2 hours. Then, monitor the reaction by thin-layer chromatography. The molar ratio of 4-(dimethylamino)-m-phenylenedialdehyde to 4-cyanophenylacetonitrile is 1:2.

1. Step 3: After the above reaction is complete, filter while hot and wash with ethanol, and finally dry to obtain an orange powder of cyanostilbene compound.

4. The method for preparing a switch-type acid-induced color-changing cyanostilbene compound according to claim 3, characterized in that, In step two, the reflux reaction is carried out at 75°C for 2 hours.

5. The method for preparing a switch-type acid-induced color-changing cyanostilbene compound according to claim 3, characterized in that, The follow-up reaction in step two is a thin-layer chromatography follow-up reaction using PE:EA = 1:1 as the developing solvent.

6. A white light-emitting diode utilizing the switch-type acid-chromic cyanostilbene compound of claim 1, characterized in that, The preparation method is as follows: 5-10g of silica gel is mixed with 20-40mg of cyanostilbene compound and degassed in a vacuum. The mixture is then cured on an InGaN blue light chip for 1-2 hours to obtain a light-emitting diode optical device.

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