Preparation method and anti-counterfeiting application of bialkyne photochromic fluorescent dye

Abstract

The invention discloses a micromolecular bialkyne dye with photochromic performance. The structure of the micromolecular bialkyne dye is shown as a formula I, substituted salicylaldehyde is taken as a raw material and reacts with an intermediate generated after propargyl bromide is reacted under the action of alkali, a copper catalyst and a ligand, and the dialkyne dye is obtained. The synthesis method has the advantages of easily available raw materials, mild reaction conditions and high yield. The dialkyne molecule constructed by the method has photochromic performance, can be used for a novel anti-counterfeiting strategy, and has a wide application prospect. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the fields of organic chemical synthesis and anti-counterfeiting, and particularly relates to a preparation method of a diyne-based photochromic fluorescent dye and its application in the field of anti-counterfeiting.

Background Art

[0002] Diyne molecules can generate polyethynylene under light irradiation. Their unique conjugated enyne backbone forms a π-electron delocalization channel through alternating single-double bond arrangements. This electron conduction property not only endows the material with excellent electrical conductivity, but also enables the polymer to undergo a coordinated change in the electron cloud distribution and molecular structure under external stimuli such as light, electricity, and temperature, and is converted into a macroscopically visible color response through the intermolecular exciton coupling effect. Liposomes constructed using the properties of polyethynylene have been widely studied in the fields of cell tracking and labeling, drug delivery, and intelligent biomaterials. However, due to the complex preparation process and high molding difficulty of macromolecular polyethynylene, it is difficult to achieve an ideal morphology, resulting in most research being limited to the laboratory stage. In contrast, small molecule polymers have the advantages of simple structure and definite molecular weight, which can improve the homogeneity and predictability of the material. Currently, the main synthesis methods of small molecule diynes have the following limitations: 1. The copper / TMEDA / piperidine system: requires the introduction of oxygen, but piperidine has strong irritation and flammability, posing a safety hazard; 2. The tetrakis(triphenylphosphine)palladium / silver oxide system: the catalyst cost is high and the economy is poor; 3. The copper / sodium carboxymethyl cellulose system: uses the difficult-to-treat DMSO solvent and the post-treatment is complex. It should be noted that the synthesis of aldehyde group-modified diyne molecules has not been reported in the above methods. Therefore, developing a new strategy for efficient, safe and functionalizable diyne synthesis and studying its photochromic properties and applications has important research significance.

Summary of the Invention

[0003] The purpose of the present invention is to provide a diyne-based photochromic fluorescent dye and its preparation method.

[0004] The technical solution is as follows:

[0005] A diyne-based photochromic fluorescent dye has the structure shown in Formula I:

[0006]

[0007] Among them, R is an alkyl group with a carbon atom number less than or equal to 4 or a phenyl group.

[0008] The synthesis route is as follows:

[0009]

[0010] Synthesis steps:

[0011] (1) The substituted salicylaldehyde A is dissolved in a solvent, and a base and 3-bromopropyne are added, and the reaction gives B;

[0012] (2) B is added with a base, a copper catalyst, and a ligand, and the reaction gives the target product I.

[0013] In step (1), the base is selected from potassium tert-butoxide or potassium carbonate, the reaction solvent is selected from acetonitrile or N,N-dimethylformamide, the reaction solvent is selected from acetonitrile or N,N-dimethylformamide, and the molar ratio of the substituted salicylaldehyde to 3-bromopropyne is 1:1 to 2, and the reaction temperature is 20 to 45 °C;

[0014] In step (2), the solvent is acetonitrile, the base is selected from potassium phosphate, dipotassium hydrogen phosphate or sodium carbonate, the copper catalyst is selected from copper(I) catalysts such as copper(I) iodide and copper(I) chloride, the ligand is selected from indanone ligands such as 1-indanone and 5-hydroxy-1-indanone, and the molar ratio of the substituted salicylaldehyde to the base, the copper catalyst and the ligand is 1:0.3 to 0.8:0.5 to 1:0.5 to 1.3, the reaction time is 1 to 3 h, and the reaction temperature is 70 to 90 °C;

[0015] The second object of the present invention is to provide an application of the diyne-based photochromic fluorescent dye in the field of anti-counterfeiting. The diyne-based photochromic fluorescent dye of the present invention can rapidly change from blue fluorescence to yellow fluorescence under ultraviolet lamp irradiation and can be applied to anti-counterfeiting.

[0016] Among them, the wavelength range of the ultraviolet lamp is 200 nm - 400 nm.

[0017] The diyne-based photochromic fluorescent dye can be used alone or doped with other components. It also has good photochromic properties in the plastic film doped with the dye, and multiple new anti-counterfeiting strategies can be constructed by combining with dyes of the same color system, which has high application value in product anti-counterfeiting.

[0018] The present invention has the following advantages compared with the prior art:

[0019] 1. The provided synthesis method has mild reaction conditions, simple synthesis operation, the product is easy to separate and purify, and a new diyne molecule containing an aldehyde group substituent with fluorescence performance is constructed.

[0020] 2. The various diyne molecules prepared by the present invention have obvious photochromic properties and have application value in aspects such as fluorescence anti-counterfeiting.

Description of the Drawings

[0021] Figure 1 is the 1H NMR spectrum of the compound B-1 prepared in Example 1.

[0022] Figure 2 is the 1H NMR spectrum of the compound I-1 prepared in Example 2.

[0023] Figure 3 It is the high-resolution mass spectrum of Compound I-2 prepared in Example 2.

[0024] Figure 4 It is the 1H NMR spectrum of Compound B-2 prepared in Example 3.

[0025] Figure 5 It is the 1H NMR spectrum of Compound I-2 prepared in Example 4.

[0026] Figure 6 It is the 13C NMR spectrum of Compound I-2 prepared in Example 4.

[0027] Figure 7 It is the high-resolution mass spectrum of Compound I-2 prepared in Example 4.

[0028] Figure 8 It is the single crystal structure of Compound I-2 prepared in Example 4.

[0029] Figure 9 It is the 1H NMR spectrum of Compound A-3 prepared in Example 5.

[0030] Figure 10 It is the 1H NMR spectrum of Compound B-3 prepared in Example 6.

[0031] Figure 11 It is the 1H NMR spectrum of Compound I-3 prepared in Example 7.

[0032] Figure 12 It is the 13C NMR spectrum of Compound I-3 prepared in Example 7.

[0033] Figure 13 It is the high-resolution mass spectrum of Compound I-3 prepared in Example 7.

[0034] Figure 14 It is the UV-Vis absorption spectrum of Compound I-2 tested in Example 8.

[0035] Figure 15 It is the fluorescence emission spectrum of Compound I-2 tested in Example 8.

[0036] Figure 16 It is the UV-Vis absorption spectrum and fluorescence emission spectrum of Compound I-2 tested in Example 9 before and after irradiation with a 365 nm UV lamp in different solvents.

[0037] Figure 17 It is the fluorescence emission spectrum of Compound I-2 with different concentrations irradiated with a 365 nm UV lamp tested in Example 10.

[0038] Figure 18 It is the fluorescence emission spectrum of the polymerized Compound I-2 irradiated with a 427 nm UV lamp tested in Example 11.

[0039] Figure 19 It is the CIE chromaticity diagram of the polymerized compound I-2 tested in Example 11 after irradiation with a 427 nm ultraviolet lamp.

[0040] Figure 20 It is the scanning electron microscope image of the compound I-2 tested in Example 12 after irradiation with a 365 nm ultraviolet lamp.

[0041] Figure 21 It is the fluorescence change of the plastic film made of the compound I-2 tested in Example 13 after irradiation with a 365 nm ultraviolet lamp.

[0042] Figure 22 It is a photo of the anti-counterfeiting plastic film made of the compound I-2 and the same color system dye tested in Example 14.

[0043] Figure 23 It is the fluorescence change of the anti-counterfeiting plastic film made of the compound I-2 and the same color system dye tested in Example 14 after irradiation with a 365 nm ultraviolet lamp.

Specific Embodiments

[0044] The present invention will be described below through specific examples, but the present invention is not limited thereto.

[0045] The experimental methods described in the following examples are all conventional methods unless otherwise specified; the drugs and solvents can all be purchased commercially.

[0046]

Example 1

[0047] Prepare intermediate B-1:

[0048]

[0049] 1.33 g (8 mmol) of 4-dimethylaminosalicylaldehyde A-1 and 2.21 g (16 mmol) of K2CO3 were placed in a 50 mL flask, then 30 mL of acetonitrile was added, and 1.428 (12 mmol) of 3-bromopropyne was added thereto. Stir at room temperature for 6 h, and the solution turned light brown. The reaction was monitored by TLC until the reaction was complete. After extraction with water and dichloromethane and vacuum drying, 1.60 g of brown crystals B1 were obtained, with a yield of 98.5%. 1 H NMR (500 MHz, CDCl3) δ 10.10 (d, J = 0.8 Hz, 1H), 7.68 (d, J = 8.9 Hz, 1H), 6.29 (ddd, J = 8.9, 2.3, 0.8 Hz, 1H), 6.15 (d, J = 2.3 Hz, 1H), 4.74 (d, J = 2.4 Hz, 2H), 3.02 (s, 6H), 2.50 (t, J = 2.4 Hz, 1H).

[0050]

Example 2

[0051] Preparation of the target product I-1:

[0052]

[0053] Weigh 1.22 g (6 mmol) of the intermediate B-1 compound into a 50 mL dry flask, add 0.76 g (4 mmol) of copper(I) iodide, 1.50 g (3 mmol) of potassium phosphate, 0.67 g (4.5 mmol) of 5-hydroxy-1-indanone, then add 30 mL of acetonitrile and heat to 80 °C. After stirring for 1 h, the solution turns dark brown. Monitor the reaction by TLC until the reaction is complete. After cooling, filter by suction, wash with ethyl acetate, and dry under vacuum to obtain 0.91 g of an off-white solid with a yield of 75.1%. 1 H NMR (500 MHz, DMSO-d6) δ 9.99 (s, 1H), 7.54 (d, J = 8.9 Hz, 1H), 6.45–6.40 (m, 1H), 6.29 (d, J = 2.2 Hz, 1H), 5.15 (s, 2H), 3.04 (s, 6H). HRMS: m / z [M+H] + calcd for C 24 H 25 N2O4 + , Theory: 405.1809, Found: 405.1818.

[0054]

Example 3

[0055] Preparation of the intermediate B-2:

[0056]

[0057] 1.55 g (8 mmol) of 4-diethylaminosalicylaldehyde A-2 and 2.21 g (16 mmol) of K2CO3 are placed in a 50 mL flask, then add 30 mL of acetonitrile, and then add 1.43 (12 mmol) of 3-bromopropyne. Stir at room temperature for 6 h, and the solution turns light brown. Monitor the reaction by TLC until the reaction is complete. After extraction with water and dichloromethane and drying under vacuum, 1.68 g of brown crystals B-2 are obtained with a yield of 96.8%. 11H NMR (500 MHz, Chloroform-d) δ 8.24 (d, J = 9.3 Hz, 1H), 8.01 (s, 1H), 6.37 (dd, J = 9.3, 2.4 Hz, 1H), 6.18 (d, J = 2.4 Hz, 1H), 4.77 (d, J = 2.4 Hz, 2H), 3.46 (q, J = 7.1 Hz, 4H), 2.59 (t, J = 2.4 Hz, 1H), 1.25 (t, J = 7.1 Hz, 6H).

[0058]

Example 4

[0059] Prepare the compound of formula I-2:

[0060]

[0061] Weigh 1.39 g (6 mmol) of the intermediate B-2 compound into a 50 mL dry flask, add 0.39 g (4 mmol) of copper chloride, 2.00 g (4 mmol) of potassium phosphate, 0.53 g (4 mmol) of 1-indanone, then add 30 mL of acetonitrile and heat to 80 °C. After stirring for 2 h, the solution turns dark brown. Monitor the reaction by TLC until the reaction is complete. After cooling, filter by suction, wash with ethyl acetate, and dry in vacuo to obtain 0.89 g of an off-white solid with a yield of 64.5%. 1 1H NMR (500 MHz, DMSO-d6) δ 9.97 (s, 1H), 7.53 (d, J = 8.9 Hz, 1H), 6.40 (dd, J = 8.9, 2.2 Hz, 1H), 6.24 (d, J = 2.2 Hz, 1H), 5.14 (s, 2H), 3.43 (q, J = 7.0 Hz, 4H), 1.10 (t, J = 7.0 Hz, 6H). 13 13C NMR (125 MHz, DMSO) δ 185.5, 161.7, 153.8, 130.3, 114.0, 105.5, 95.0, 76.5, 70.8, 56.6, 44.7, 12.8. HRMS: m / z [M + H] + calcd for C 28 H 32 N2NaO4 + , Theory: 483.2254, Found: 483.2250.

[0062]

Example 5

[0063] Prepare intermediate A-3:

[0064]

[0065] Weigh 1.01 g (5 mmol) of p-bromosalicylaldehyde and 2.02 g (7 mmol) of 4-borotriphenylamine into a 100 mL dry flask. Add 3.46 g (25 mmol) of potassium phosphate and 0.29 g (0.25 mmol) of tetrakis(triphenylphosphine)palladium. Then add 30 mL of ethylene glycol dimethyl ether and 24 mL of water. Under nitrogen protection, heat the mixture to 110 °C and stir for 12 h. The solution turns brownish-yellow. Monitor the reaction by TLC until it is complete. After cooling to room temperature, extract with ethyl acetate and water and dry under vacuum to obtain the crude product. After column chromatography of the crude product, 0.89 g of bright yellow solid is obtained, with a yield of 86.3%. 1 H NMR (500 MHz, CDCl3) δ 11.06 (s, 1H), 9.81 (s, 1H), 7.50 (d, J = 8.1 Hz, 1H), 7.44 (d, J = 8.7 Hz, 2H), 7.26–7.20 (m, 4H), 7.16 (dd, J = 8.1, 1.7 Hz, 1H), 7.11 (d, J = 1.6 Hz, 1H), 7.09–7.06 (m, 4H), 7.06–7.03 (m, 2H), 7.01 (tt, J = 7.4, 1.2 Hz, 2H).

[0066]

Example 6

[0067] Prepare the compound of formula B-3:

[0068]

[0069] Add 2.92 g (8 mmol) of A-3 and 2.21 g (16 mmol) of K2CO3 to a 50 mL flask. Then add 30 mL of acetonitrile, and add 1.43 (12 mmol) of 3-bromopropyne to it. Stir at room temperature for 8 h. The solution turns light brown. Monitor the reaction by TLC until it is complete. After extraction with water and dichloromethane and drying under vacuum, 1.47 g of brownish-yellow crystals of B-3 are obtained, with a yield of 91.2%. 1 H NMR (500 MHz, DMSO-d6) δ 10.33 (s, 1H), 7.76 (d, J = 7.9 Hz, 1H), 7.71 (d, J = 8.6 Hz, 2H), 7.51 (s, 1H), 7.40 (d, J = 8.1 Hz, 1H), 7.35 (t, J = 7.9 Hz, 4H), 7.14–7.07 (m, 6H), 7.05 (d, J = 8.4 Hz, 2H), 5.12 (d, J = 2.4 Hz, 2H), 3.77–3.58 (m, 1H).

[0070]

Example 7

[0071] Prepare the compound of formula I-3:

[0072]

[0073] Weigh 2.42 g (6 mmol) of intermediate B-3 compound into a 100 mL dry flask, add 0.59 g (6 mmol) of copper chloride, 1.50 g (3 mmol) of potassium phosphate, 0.95 g (7.2 mmol) of 1-indanone, then add 50 mL of acetonitrile and heat to 80 °C. After stirring for 3 h, the solution turns dark brown. Monitor the reaction by TLC until the reaction is complete. After cooling, filter by suction, wash with ethyl acetate, and dry in vacuo to obtain 1.39 g of a yellow solid with a yield of 57.6%. 1 H NMR (500 MHz, CDCl3) δ 10.35 (s, 1H), 7.79 (d, J = 8.0 Hz, 1H), 7.36 (d, J = 8.4 Hz, 2H), 7.21 (t, J = 7.8 Hz, 4H), 7.17 (d, J = 8.2 Hz, 1H), 7.10 (s, 1H), 7.08–7.03 (m, 4H), 7.03–6.97 (m, 4H), 4.88 (s, 2H). 13 C NMR (125 MHz, CDCl3) δ 188.8, 159.8, 148.6, 148.3, 147.3, 132.7, 129.5, 129.3, 128.0, 125.0, 123.8, 123.6, 122.9, 120.3, 110.7, 74.3, 71.8, 56.7. HRMS: m / z [M + H] + calcd for C 56 H 41 N2O4 + , Theory: 805.3061, Found: 805.3025.

[0074]

Comparative Example 1

[0075] Prepare compound I-2:

[0076]

[0077] Weigh 1.39 g (6 mmol) of intermediate B-2 compound into a 50 mL dry flask, add 0.39 g (4 mmol) of copper chloride, 2.00 g (4 mmol) of potassium phosphate, then add 30 mL of acetonitrile and heat to 80 °C. After stirring for 2 h, the solution turns dark. Monitor the reaction by TLC, and the target product cannot be detected

[0078]

Comparative Example 2

[0079] Prepare compound I-2:

[0080]

[0081] Weigh 1.39 g (6 mmol) of intermediate B-2 compound into a 50 mL dry flask, add 0.39 g (4 mmol) of copper chloride, 2.00 g (4 mmol) of potassium phosphate, 0.48 g (4 mmol) of acetophenone, then add 30 mL of acetonitrile and heat to 80 °C. After stirring for 2 h, the solution becomes darker. Monitor the reaction by TLC, and the target product can be detected in all cases.

[0082]

Comparative Example 3

[0083] Prepare compound I-2:

[0084]

[0085] Weigh 1.39 g (6 mmol) of intermediate B-2 compound into a 50 mL dry flask, add 0.39 g (4 mmol) of copper chloride, 2.00 g (4 mmol) of potassium phosphate, 0.73 g (4 mmol) of benzophenone, then add 30 mL of acetonitrile and heat to 80 °C. After stirring for 2 h, the solution becomes darker. Monitor the reaction by TLC, and the target product cannot be detected.

[0086]

Comparative Example 4

[0087] Prepare compound I-2:

[0088]

[0089] Weigh 1.39 g (6 mmol) of intermediate B-2 compound into a 50 mL dry flask, add 0.39 g (4 mmol) of copper chloride, 2.00 g (4 mmol) of potassium phosphate, 0.46 g (4 mmol) of TMEDA, then add 30 mL of acetonitrile and heat to 80 °C. After stirring for 2 h, the solution becomes darker. Monitor the reaction by TLC, and the target product cannot be detected.

[0090]

Example 8

[0091] Prepare a 10 μmol / L solution of I-2 and test its ultraviolet-visible absorption spectrum and fluorescence emission spectrum.

[0092] The photophysical properties of the target molecule I-2 solution in the above examples are shown in Table 1:

[0093] Table 1: Photophysical properties of I-2

[0094]

[0095]

Example 9

[0096] Prepare a 0.1 mmol / L solution of I-2, and test its ultraviolet-visible absorption spectrum and fluorescence emission spectrum in different solutions before and after irradiation with a 365 nm ultraviolet lamp, to explore the fluorescence change of the diyne molecule before and after light irradiation.

[0097] The CIE coordinates of the target molecule I-2 in different solvents before and after irradiation with 365 nm ultraviolet light in the above examples are shown in Table 2:

[0098] Table 2: CIE coordinates of DA-1 (0.1 mM) in different solvents before and after irradiation with 365 nm ultraviolet light

[0099]

[0100]

[0101]

Example 10

[0102] Prepare three I-2 solutions with different concentrations of 1 mM, 0.1 mM, and 0.01 mM, and respectively conduct fluorescence emission spectrum tests to explore the photochromic behavior of diyne molecules with different concentrations. As the irradiation time increases, the fluorescence of the diyne monomer at 387 nm decreases, and the fluorescence of the polyethynylene molecule at 563 nm increases. The fluorescence intensity shows a good linear relationship with the response time. The photochromic process is completed in a short time and has good responsiveness to ultraviolet light.

[0103]

Example 11

[0104] To explore the influence of the irradiation wavelength on the photochromic behavior, first continuously irradiate the I-2 solution with 365 nm ultraviolet light for 3 minutes, and then irradiate the solution with 427 nm visible light for different durations. The test results are as Figure 18 and 19 shown. During this process, it is observed that the intensity of the fluorescence emission peak at 563 nm continuously decreases, while the intensity of the fluorescence emission peak at 387 nm continuously increases. This phenomenon proves that under the irradiation of 427 nm visible light, the polydiacetylene undergoes a depolymerization reaction, thus promoting the dye to return to the initial state.

[0105]

Example 12

[0106] Drop the pre-prepared ethanol solution of the dye I-2 evenly on the surface of the silicon wafer substrate. Use a 365 nm ultraviolet light source to irradiate the sample for 1 minute. After the solvent naturally evaporates and dries, sputter gold to enhance its conductivity, and finally use a high-resolution scanning electron microscope (SEM) for precise morphology observation and analysis. The test results are as Figure 20 shown. The DA-1 diyne molecule undergoes a polymerization reaction after light irradiation, and the polymer shows a blocky morphology distribution, with rich wrinkles, roughness, and unevenness on its surface.

[0107]

Example 13

[0108] The alkynyl dye I-2 was made into a film pre-formulation and spread on glass to obtain a color-changing plastic film. When not irradiated with ultraviolet light, the color-changing plastic film emits blue fluorescence; after being irradiated with an ultraviolet lamp for 7 s, due to the generation of polymers, the film emits yellow fluorescence.

[0109]

Example 14

[0110] The alkynyl dye can be used in combination with other dyes according to different requirements to achieve the purpose of anti-counterfeiting. A film pre-formulation was prepared by mixing the previously developed non-fluorescent orange-yellow dye and spread on glass. Then, the film pre-formulation prepared with I-2 was used to draw the anti-counterfeiting pattern of "letter A". After a series of operations, a color-uniform and transparent anti-counterfeiting color-changing plastic film was obtained. When not irradiated with an ultraviolet lamp, the drawn "letter A" shows blue fluorescence. After being irradiated with ultraviolet light for 10 s, the "letter A" emits yellow fluorescence as a whole. The verification process is simple, the visual effect is prominent, the information involved in the process is complex and difficult to be replicated, and it has great application potential in the field of anti-counterfeiting.

Claims

1. A diyne-based photochromic fluorescent dye, characterized in that, The structural formula is as shown in Formula I: Wherein, R is an alkyl group with a carbon atom number less than or equal to 4 or a phenyl group.

2. The preparation method of the alkynyl-linked photochromic fluorescent dye according to claim 1, characterized in that, The synthesis route is as follows: Specific steps: Step (1), the substituted salicylaldehyde A is dissolved in a solvent, an alkali and 3-bromopropyne are added, and reaction gives B; Step (2), B is added with an alkali, a copper catalyst and a ligand, and reaction gives the target product I.

3. The preparation method of the enediyne-based photochromic fluorescent dye according to claim 2, wherein In Step (2), the ligand is one or a mixture of 1-indanone or 5-hydroxy-1-indanone.

4. The application of an alkynyl-based photochromic fluorescent dye as described in claim 1, characterized in that, The diyne-based photochromic fluorescent dye exhibits blue fluorescence, and after ultraviolet light irradiation, the fluorescent dye exhibits yellow fluorescence, and can be applied in anti-counterfeiting.

5. The application according to claim 4, wherein The wavelength range of the ultraviolet lamp is 200 nm - 400 nm.

6. The application according to claim 4, wherein The diyne-based photochromic fluorescent dye can be used alone or doped with other components.

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