Preparation and application of a dithiazole-quinoline derivative dye

Abstract

The present invention discloses the preparation and application of a quinoline-dithiazolidine derivative, and studies the effects of substituents and π-conjugated systems on optical properties. The method comprises dissolving a quinoline derivative and dithiooxamide (2,5-diamino-1,4-benzenedithiol dihydrochloride) in N,N-dimethylformamide solvent, stirring at 120°C for 12 hours, and then separating and purifying to obtain the fluorescent dye. The product synthesized by the present invention has a large conjugated system, and the solid fluorescence can be regulated accordingly with changes in the substituents. The preparation method of this type of fluorescent dye is simple and easy, the raw materials are simple and readily available, the cost is low, and it has good performance. It can be applied in the fields of luminescent materials, fluorescent inks (printing materials), anti-counterfeiting materials, printing and dyeing industries, sensors, etc.

Description

Technical Field

[0001] The present invention belongs to the field of dye fine chemicals, and specifically relates to a new type of fluorescent dye that is simple and easy to synthesize. The fluorescent emission wavelength can be adjusted to a certain extent and can be applied to luminescent materials, fluorescent inks (printing materials), anti-counterfeiting materials, printing and dyeing industries, and sensors. Background Art

[0002] At present, many substances with special chemical, physical and electrical properties are used to prevent and detect counterfeits. Chemical anti-counterfeiting is a new technology developed in recent years, with the advantages of simple preparation, easy identification, low cost, good confidentiality and high reliability. The so-called chemical anti-counterfeiting is a method of identifying authenticity by using chemical reactions and physical changes of substances under conditions such as heat, light or magnetism. Among them, fluorescent anti-counterfeiting marking technology uses the characteristics of fluorescent emission produced by fluorescent materials under ultraviolet light. Compared with general anti-counterfeiting technologies such as watermarks, lasers, and color-changing inks, fluorescent anti-counterfeiting marks are transparent under visible light, do not affect the original appearance of the item, have good privacy, and exhibit characteristic fluorescence under ultraviolet light, achieving the purpose of anti-counterfeiting identification. Therefore, fluorescent dyes need to be easy to print, impregnate, and have high fluorescence intensity. In addition, the low synthesis cost of fluorescent dyes, simple and efficient preparation methods, and ease of use are also issues of general concern.

[0003] Material anti-counterfeiting technology has developed into various forms. However, a single anti-counterfeiting method is still easy to be cracked and counterfeited by criminals to a certain extent. In order to achieve a complete anti-counterfeiting effect, the current application trend in the anti-counterfeiting field is to integrate multiple anti-counterfeiting technologies to make anti-counterfeiting materials with multiple functions, the combination of various material anti-counterfeiting technologies, and the combination of material anti-counterfeiting technology and laser holographic anti-counterfeiting technology. Therefore, fluorescent anti-counterfeiting materials are required to have high durability and be easy to be combined with multiple anti-counterfeiting technologies. Summary of the Invention

[0004] The present invention aims to synthesize a series of fluorescent dyes with tunable luminescence, derived from dithiazolyl-quinoline derivatives. The fluorescence wavelength of these compounds can be adjusted by varying the substituents. The synthesized fluorescent dyes have applications in luminescent materials, fluorescent inks (printing materials), anti-counterfeiting materials, the printing and dyeing industry, and sensors.

[0005] The purpose of the present invention is achieved by the following technical solution: The solid fluorescent dye of the present invention has the following structural formula:

[0006]

[0007] The substituent R includes diethylamino, methoxy, and hydrogen.

[0008] The preparation method of the fluorescent dye compound comprises the following steps: dissolving a quinoline derivative and dithiooxamide (2,5-diamino-1,4-benzenedithiol dihydrochloride) in an N,N-dimethylformamide solvent, stirring and reacting at 120°C for 12 hours, and then separating and purifying to obtain the fluorescent dye.

[0009] The specific synthesis route of the fluorescent dye is as follows:

[0010]

[0011] The substituent R includes diethylamino, methoxy, and hydrogen.

[0012] The molar ratio of the quinoline derivative to dithiooxamide (2,5-diamino-1,4-benzenedithiol dihydrochloride) is 2: (1-1.5).

[0013] Traditional organic molecular chromophores face the problem of fluorescence quenching at high concentrations, in solid or thin film aggregates, but the present invention overcomes or mitigates this quenching phenomenon and red-shifts the wavelength by modifying the conjugated system and electron-donating groups. This method requires only vacuum filtration, eliminating the need for column chromatography purification, to obtain the final product, making it simple to operate. The present invention combines different quinoline derivatives with dithiooxamide and 2,5-diamino-1,4-benzenedithiol dihydrochloride, respectively, to produce a series of solid fluorescent dyes. The benzothiazole nucleus, present in many small molecule fluorescent compounds, has attracted considerable attention due to its high fluorescence quantum yield and the ease of synthesis of its heterocyclic ring. Thiazole and quinoline are both common and popular organic luminophores, commonly used in chemistry, life sciences, medicine, environmental analysis, cell staining, signal tracking, and other fields. This invention offers promising prospects for the application of organic chromophores in various fields. By varying the type of phenyl ring substituents, the present invention can significantly alter the fluorescence quantum yield and wavelength of the product, thereby changing the emission color of the solid fluorescent dye.

[0014] The fluorescent dyes described in this invention are simple and easy to synthesize, using readily available raw materials at low cost. The organic solid fluorescent dyes of this invention exhibit excellent properties and are suitable for applications in luminescent materials, fluorescent inks (printing materials), anti-counterfeiting materials, the printing and dyeing industry, and sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the H NMR spectrum of ZH-1 dye.

[0016] Figure 2 This is the H NMR spectrum of ZH-2 dye.

[0017] Figure 3 This is the H NMR spectrum of YH-1 dye.

[0018] Figure 4 This is the H NMR spectrum of YH-2 dye.

[0019] Figure 5 This is the H NMR spectrum of YH-3 dye.

[0020] Figure 6 The fluorescence emission spectra of ZH-1 and YH-1 in several polar solvents and the fluorescence images under 365nm ultraviolet light.

[0021] Figure 7 The present invention relates to the application of dyes in anti-counterfeiting films. DETAILED DESCRIPTION

[0022] Example 1: Synthesis of Compound ZH-1

[0023] Weigh 50 mg (0.22 mol) of 6-(diethylamino)quinoline-2-carboxaldehyde and 13.2 mg (0.11 mol) of dithiooxamide into a 25 ml reaction flask. Dissolve in 2 ml of DMF. Stir in an oil bath at 120°C for 12 hours. Filter under reduced pressure to obtain 29.7 mg of a red solid. The yield is 25%.

[0024] Example 2: Synthesis of Compound ZH-2

[0025] Weigh 50 mg (0.267 mol) of 6-methoxyquinoline-2-carboxaldehyde and 21.2 mg (0.34 mol) of dithiooxamide into a 25 ml reaction flask. Dissolve in 2 ml of DMF. Stir in an oil bath at 120°C for 12 hours. Filter under reduced pressure to obtain 42 mg of a yellow solid. The yield is 34%.

[0026] Example 3: Synthesis of Compound YH-1

[0027] Weigh 50 mg (0.22 mol) of 6-(diethylamino)quinoline-2-carboxaldehyde and 27 mg (0.11 mol) of 2,5-diamino-1,4-benzenedithiol dihydrochloride into a 25 mL reaction flask. Dissolve the mixture in 2 mL of DMF. Stir in an oil bath at 120°C for 12 hours. Filter under reduced pressure to obtain 40.7 mg of a light red solid. The yield is 31%.

[0028] Example 4: Synthesis of Compound YH-2

[0029] Weigh 50 mg (0.32 mol) of quinoline-2-carboxaldehyde and 39 mg (0.16 mol) of 2,5-diamino-1,4-benzenedithiol dihydrochloride into a 25 ml reaction flask. Dissolve in 2 ml of DMF. Stir in an oil bath at 120°C for 12 hours. Filter under reduced pressure to obtain 37.5 mg of a green solid. The yield is 26%.

[0030] Example 5: Synthesis of Compound YH-3

[0031] Weigh 50 mg (0.267 mol) of 6-methoxyquinoline-2-carboxaldehyde and 32.7 mg (0.134 mol) of 2,5-diamino-1,4-benzenedithiol dihydrochloride into a 25 ml reaction flask. Dissolve in 2 ml of DMF. Stir in an oil bath at 120°C for 12 hours. Filter under reduced pressure to obtain 38.1 mg of a yellow solid. The yield is 28%.

[0032] Example 6: Effects of dyes in solvents of different polarities

[0033] Take the prepared ZH-1, ZH-2, YH-1, YH-2, and YH-3 compounds and dissolve them in DCM solution to prepare a 1mM mother liquor. Add DCM, DMSO, ethanol, and toluene to the test tubes, 3mL per test tube, take out 6μL (2μM) from the mother liquor and add it to each test tube. Use ZH-1 excitation wavelength of 480nm and YH-1 excitation wavelength of 460nm, and use UV-visible absorption spectrometer and fluorescence spectrometer to test the UV-visible absorption spectrum and fluorescence spectrum of the dye in different polar solvents. The test results are shown in Figure 6 , it can be seen that the wavelength of dye ZH-1 in four polar solvents, Tol, DCM, EtOH, and DMSO, is red-shifted ( Figure 6 A), the fluorescence color of the solution ( Figure 6 In B, the solvents from left to right are Tol, DCM, EtOH, and DMSO) from green to yellow to orange; in the four polar solvents of Tol, DCM, EtOH, and DMSO, the wavelength of YH-1 red-shifts as the polarity increases ( Figure 6 C), the fluorescence color of the solution ( Figure 6 In middle D, from left to right the solvents are Tol, DCM, EtOH, and DMSO) from blue to green to yellow-orange.

[0034] Example 7: Application of dyes in anti-counterfeiting.

[0035] Take the prepared ZH-1, ZH-2, YH-1, YH-2, and YH-3 compounds, dissolve them in acrylic resin solution to make a 1 mg / ml solution, and then evenly apply it on sulfuric acid paper ( Figure 7 Where S, D, X, Y, and W are compounds ZH-1, ZH-2, YH-1, YH-2, and YH-3, respectively. After cooling and forming a film, the film was irradiated with ultraviolet light and photographed. Figure 7 It can be seen that the film formed on the sulfuric acid paper has almost no color change observed under sunlight, but obvious fluorescence changes can be seen under ultraviolet light. Therefore, this series of dyes has potential for application in anti-counterfeiting.

Claims

1. A dithiazole-quinoline derivative dye, characterized in that: The structural formula of the dithiazole-quinoline derivative dye is selected from any one of the following: 。 2. The method for preparing a dithiazolidine-quinoline derivative dye according to claim 1, wherein: The following steps are involved: A quinoline derivative and 2,5-diamino-1,4-benzenedithiol dihydrochloride are dissolved in N,N-dimethylformamide solvent, stirred and reacted at 100-120° C. for 10-12 hours, and then filtered under reduced pressure to obtain the dye. The quinoline derivative is selected from 6-diethylaminoquinoline-2-carboxaldehyde, 6-methoxyquinoline-2-carboxaldehyde or quinoline-2-carboxaldehyde.

3. The method for preparing a dithiazolidine-quinoline derivative dye according to claim 2, wherein: The molar ratio of the quinoline derivative to 2,5-diamino-1,4-benzenedithiol dihydrochloride is 2:(1-1.5).

4. The method for preparing a dithiazolidine-quinoline derivative dye according to claim 2, wherein: The solvent is N,N-dimethylformamide, nitrobenzene, and THF.

5. Use of the dithiazolidine-quinoline derivative dye according to claim 1 for fluorescence emission in a polar solvent, wherein the polar solvent is toluene, dichloromethane, ethanol, or dimethyl sulfoxide.

6. Use of the dithiazolidine-quinoline derivative dye according to claim 1 as a fluorescent luminescent reagent for detecting polar solvents, wherein the polar solvent is selected from any one of toluene, dichloromethane, ethanol, or dimethyl sulfoxide.

7. Use of the dithiazolidine-quinoline derivative dye according to claim 1 in the field of anti-counterfeiting materials.

Images