Spiropyrane derivative with color and fluorescence double switches, photochromic material and preparation method and application thereof

Abstract

The invention discloses a spiropyrane derivative with color and fluorescence double switches, a photochromic material and a preparation method and application of the spiropyrane derivative. The spiropyrane derivative is a compound with a chemical structural general formula (1). The invention further discloses a photochromic material prepared by mixing the spiropyran derivative and epoxy resin and a preparation method of the photochromic material. According to the invention, an aromatic fluorophore is introduced into a side group of a spiropyrane material, and the fluorescence intensity of spiropyrane after ring opening is increased through a relatively large conjugated system of the fluorophore. The compound shows good photochromic and photoluminescence effects in both an organic solvent and a solid medium; by combining a fluorophore and a spiropyran material, a molecular switch material with remarkable color and fluorescence change can be prepared; the spiropyran derivative can be used for preparing a two-dimensional optical display device and can be used for preparing an intelligent material molecular switch.

Description

Technical Field

[0001] The invention relates to the field of organic photochromic materials, and in particular to a spiropyran derivative with color and fluorescence dual switches, a photochromic material, and a preparation method and application thereof. Background Art

[0002] As the name implies, fluorescent groups are a class of compounds with fluorescent properties. The principle of luminescence is that when exposed to light, the compound absorbs energy and enters an excited state. Due to the extreme instability of the excited state, the compound immediately de-excites, and the energy is released in the form of light, so fluorescence is generated. Most fluorescent groups have a polybenzene ring structure, which can improve the conjugation effect of the entire system, thereby enhancing the fluorescence brightness of the system.

[0003] Spiropyran is a typical organic photochromic compound. Under ultraviolet light, it changes from a closed-ring spiropyran (SP) structure to an open-ring merocyanine (MC) structure. Then, under the action of visible light or heat, the open-ring body returns to a closed-ring body. Moreover, in the closed-ring body, the indoline ring and the benzopyran ring in the spiropyran molecule are orthogonal to each other, and there is no conjugation effect; when the ring is open, the two rings change from orthogonal to planar, and the molecular conjugation effect is enhanced. At this time, the color, hydrophilicity, and fluorescence of spiropyran will change greatly. Therefore, researchers often use it as a molecular light switch material and widely apply it to analytical chemistry, optical display devices, drug controlled release and other fields. However, due to its relatively small molecular conjugated structure, its fluorescence brightness is often insufficient. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a spiropyran derivative with color and fluorescence dual switches, which is a compound having a chemical structural formula (1): Formula (1); In formula (I), R is an aromatic group, selected from any one of phenyl, indenyl, naphthyl, fluorenyl, anthracenyl and pyrenyl.

[0005] Preferably, the spiropyran derivative is any one of the following compounds:

[0006] Formula (1-1) Formula (1-2) Formula (1-3)

[0007] Formula (1-4) Formula (1-5) Formula (1-6).

[0008] Another object of the present invention is to provide a method for preparing the above-mentioned spiropyran derivatives, comprising the following steps: Step 1: Under light-proof conditions and inert gas protection, add 4-bromo-2-hydroxybenzaldehyde, 1,2,3,3-tetramethyl-3H-indole iodide and triethylamine to an anhydrous ethanol solution, and fully react at 50-90°C to precipitate a solid to obtain an intermediate; Step 2: Under the protection of inert gas, the intermediate, phenylboronic acid derivative and bis(di-tert-butyl-4-dimethylaminophosphine)palladium chloride are added to a mixed solvent, the reaction temperature is 60-90°C, and after the reaction is completed, the spiropyran derivative is obtained by separation, extraction, drying and column chromatography; the phenylboronic acid derivative is one of phenylboronic acid, indeneboric acid, naphthaleneboric acid, fluoreneboric acid, anthraceneboric acid and pyreneboric acid; the mixed solvent is a mixed solvent of sodium carbonate or potassium carbonate solution, toluene and ethanol, or a mixed solvent of sodium carbonate or potassium carbonate solution, 1,4-dioxane and ethanol.

[0009] Preferably, in step 1, the molar ratio of 4-bromo-2-hydroxybenzaldehyde to 1,2,3,3-tetramethyl-3H-indole iodide and triethylamine is 1: (0.9-1.1): (1.3-5), the reaction time is 2-18 hours, and after the reaction is completed and the temperature is lowered, a solid is precipitated, filtered, washed, and dried to obtain an intermediate; In step 2, the molar ratio of the intermediate, the phenylboronic acid derivative and the bis(di-tert-butyl-4-dimethylaminophosphine)palladium chloride is 1: (1.1-3): (0.002-0.1), and the reaction time is 3-20 hours; The volume ratio of sodium carbonate / potassium carbonate solution: toluene: ethanol in the mixed solvent is 1: (10-100): (10-50), and the concentration of sodium carbonate / potassium carbonate solution is 0.5-20 M; The volume ratio of sodium carbonate / potassium carbonate solution: 1,4-dioxane: ethanol in the mixed solvent is 1: (10-100): (10-50).

[0010] Another object of the present invention is to provide a photochromic material, which is obtained by mixing and curing the spiropyran derivative described in any one of the above items with an epoxy resin; the mass ratio of the spiropyran derivative to the epoxy resin is 1:(5000-10000).

[0011] Another object of the present invention is to provide a method for preparing the above-mentioned photochromic material, comprising the following steps: Weigh a spiropyran derivative, dissolve it in an organic solvent to prepare a solution, pour it into an epoxy resin glue, mix it evenly, pour it into a mold, and solidify it into shape and demold it to obtain the product; The organic solvent is selected from dichloromethane, dichloroethane, tetrahydrofuran, N,N-dimethylformamide and methyl tert-butyl ether; the spiropyran derivative is prepared into a 0.0001-1 g / mL solution with the organic solvent.

[0012] Preferably, the epoxy resin glue is obtained by mixing epoxy resin A glue and epoxy resin B glue in a mass ratio of 1-10:1; The epoxy resin A glue is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin and hydrogenated bisphenol A epoxy resin; The epoxy resin B glue is an aliphatic polyamine.

[0013] Preferably, the mass ratio of epoxy resin A glue to epoxy resin B glue is 3-5:1; The reaction solution is cured at room temperature for 10-30 hours.

[0014] Preferably, the epoxy resin B glue is at least one of ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine and diethylaminopropylamine.

[0015] The last object of the present invention is to provide the use of the above-mentioned spiropyran derivatives or the above-mentioned photochromic materials in the preparation of two-dimensional optical display devices and intelligent molecular switches.

[0016] The synthetic route of the spiropyran derivatives of the present invention is as follows:

[0017] The beneficial effects of the present invention are: The invention provides a method for preparing a spiropyran derivative with color and fluorescence dual switches. The method has a simple process flow and a high yield.

[0018] The present invention introduces an aromatic fluorescent group into the side group of the spiropyran material, and increases the fluorescence intensity of the spiropyran after ring opening through the larger conjugated system of the fluorescent group itself. The compound exhibits good photochromic and photoluminescent effects in both organic solvents and solid media.

[0019] By combining fluorescent groups with spiropyran materials, molecular switch materials with significant changes in color and fluorescence can be prepared; the spiropyran derivatives of the present invention can be used to prepare two-dimensional optical display devices and can be used to prepare smart material molecular switches. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 It is the NMR spectrum of compound 6 in Example 2 of the present invention.

[0021] Figure 2 This is the ultraviolet absorption spectrum of compound 6 obtained in Example 2 of the present invention before and after irradiation in dichloromethane.

[0022] Figure 3 This is a color comparison diagram of compound 6 obtained in Example 2 of the present invention before and after irradiation in dichloromethane; wherein hv1 represents ultraviolet light of 295-395nm, and hv2 represents visible light of 400-550nm.

[0023] Figure 4 This is a color comparison chart of compound 6 obtained in Example 2 of the present invention prepared in epoxy resin before and after illumination; wherein hv1 represents ultraviolet light of 295-395nm, and hv2 represents visible light of 400-550nm. DETAILED DESCRIPTION

[0024] Embodiments of the present invention are described in detail below, and the embodiments described with reference to the accompanying drawings are exemplary.

[0025] The experimental methods in the following examples are conventional methods unless otherwise specified.

[0026] The main raw materials are as follows: 4-Bromo-2-hydroxybenzaldehyde: CAS No. 22532-62-3, 1,2,3,3-Tetramethyl-3H-indole iodide: CAS No. 5418-63-3, Bis(di-tert-butyl-4-dimethylaminophosphine)palladium chloride: CAS No. 34409-44-4, Triethylamine: CAS No. 121-44-8, 9,9-Dimethylfluorene-2-boronic acid: CAS No. 333432-28-3, 9-Anthraceneboronic acid: CAS No. 100622-34-2.

[0027] Example 1 Synthesis of Compound 4 (Anthracenyl Spiropyran) 1. Preparation of anthracenyl spiropyran Follow these steps: (1) Under light-shielding conditions, 1,2,3,3-tetramethyl-3H-indole iodide (6 g, 19.92 mmol), triethylamine (3 g, 29.78 mmol), and ethanol (50 mL) were added to a reaction flask in sequence. After nitrogen was introduced to exhaust the air, a solution of 4-bromo-2-hydroxybenzaldehyde (4 g, 19.92 mmol) in ethanol (20 mL) was added. The reaction was carried out at 80° C. for 4 h. The system was cooled, filtered, washed with cold ethanol, and dried to obtain the intermediate as a white solid (3.9 g). The yield was 55.1%.

[0028] (2) After ultrasonicating a mixed solution of toluene (15 mL), ethanol (9 mL) and 1.6 M sodium carbonate aqueous solution (3 mL) for 15 min, the intermediate (0.6 g, 1.68 mmol) and 9-anthraceneboronic acid (0.49 g, 2.19 mmol) were added, and nitrogen was introduced to exhaust the air from the system. Then, bis(di-tert-butyl-4-dimethylaminophosphine)palladium chloride (0.01 g, 0.014 mmol) was added, and the reaction was carried out at 80° C. for 3 h. 15 mL of deionized water was added, and the mixture was extracted with ethyl acetate, dried over anhydrous magnesium sulfate, filtered, concentrated, and purified by column chromatography to obtain compound 4 (anthryl spiropyran) having the structural formula shown in formula (1-4) as a white solid (0.35 g, yield 45.8%).

[0029] Formula (1-4).

[0030] 2. Preparation of Photochromic Materials The specific preparation steps of the spiropyran photochromic epoxy resin material provided by the present invention are as follows: Epoxy resin A glue and B glue are mixed evenly in a mass ratio of 3:1 for use; 3.0 mg of the previously prepared compound 4 is weighed and dissolved in 1 mL of dichloromethane to prepare a solution, poured into 30 g of epoxy resin glue, mixed evenly and poured into a mold, cured at room temperature for 24 hours, and the spiropyran photochromic epoxy resin material can be obtained after demolding.

[0031] Example 2 Synthesis of Compound 6 (Fluorenyl Spiropyran) 1. Preparation of fluorenyl spiropyran Follow these steps: (1) Under light-shielding conditions, 1,2,3,3-tetramethyl-3H-indole iodide (4.7 g, 15.67 mmol), triethylamine (2.26 g, 22.38 mmol), and ethanol (50 mL) were added to a reaction flask in sequence. After nitrogen was introduced to exhaust the air, a solution of 4-bromo-2-hydroxybenzaldehyde (3 g, 14.92 mmol) in ethanol (10 mL) was added. The reaction was carried out at 80°C for 4 h. The system was cooled, filtered, washed with cold ethanol, and dried to obtain the intermediate as a white solid (3.7 g). The yield was 69.6%.

[0032] (2) After ultrasonicating a mixed solution of toluene (20 mL), ethanol (12 mL) and 1.6 M sodium carbonate aqueous solution (5 mL) for 15 min, the intermediate (1.0 g, 2.81 mmol) and 9,9-dimethylfluorene-2-boric acid (0.87 g, 3.65 mmol) were added. After nitrogen was introduced to exhaust the air from the system, bis(di-tert-butyl-4-dimethylaminophosphine)palladium chloride (0.015 g, 0.021 mmol) was added. The reaction was carried out at 80° C. for 4 h. 15 mL of deionized water was added, and the mixture was extracted with ethyl acetate, dried over anhydrous magnesium sulfate, filtered, concentrated, and purified by column chromatography to obtain compound 6 (fluorenyl spiropyran) having the structural formula shown in formula (1-6) as yellow crystals (0.72 g, yield 54.6%).

[0033] Formula (1-6).

[0034] The results of H NMR spectrum detection of compound 6 are: 1 H NMR (400 MHz, CDCl3) δ 7.71 (dd, J = 7.2,4.0 Hz, 2H), 7.59 (d, J = 1.0 Hz, 1H), 7.53 (dd, J = 7.9, 1.5 Hz, 1H), 7.42 (dd, J = 8.1, 6.5 Hz, 1H), 7.35 – 7.27 (m, 2H), 7.22 – 7.02 (m, 5H), 6.98 – 6.68 (m,2H), 6.55 (d, J = 7.7 Hz, 1H), 5.71 (d, J = 10.2 Hz, 1H), 2.78 (s, 3H), 1.49 (d, J = 1.7 Hz, 9H), 1.37 (s, 3H), 1.20 (s, 3H). The NMR spectrum and UV absorption spectrum of compound 6 are shown as follows: Figure 1 , 2 The color change comparison of compound 6 before and after irradiation in dichloromethane is shown in Figure 3 shown.

[0035] 2. Preparation of Photochromic Materials The specific preparation steps of the spiropyran photochromic epoxy resin material provided by the present invention are as follows: Epoxy resin A glue and epoxy resin B glue are mixed evenly in a mass ratio of 4:1 for use; 5.0 mg of the previously prepared compound 6 is weighed and dissolved in 1 mL of dichloromethane to prepare a solution, poured into 40 g of epoxy resin glue, mixed evenly and poured into a mold, cured at room temperature for 20 hours, and the spiropyran photochromic epoxy resin material can be obtained after demolding. Figure 4 The figure is a color comparison diagram of the prepared photochromic epoxy resin material before and after illumination, wherein hv1 represents ultraviolet light of 295-395nm, and hv2 represents visible light of 400-550nm.

[0036] Example 3 Synthesis of Compound 3 (Naphthyl Spiropyran) 1. Preparation of naphthyl spiropyran Follow these steps: (1) Under light-shielding conditions, 1,2,3,3-tetramethyl-3H-indole iodide (10 g, 33.22 mmol), triethylamine (3.8 g, 38 mmol), and ethanol (100 mL) were added to a reaction flask in sequence. After nitrogen was introduced to exhaust the air, a solution of 4-bromo-2-hydroxybenzaldehyde (6.6 g, 33 mmol) in ethanol (30 mL) was added. The reaction was carried out at 85° C. for 6 h. The system was cooled, filtered, washed with cold ethanol, and dried to obtain the intermediate as a white solid of 7.6 g, with a yield of 65%.

[0037] (2) After ultrasonic treatment for 10 min in a mixed solution of toluene (30 mL), ethanol (25 mL) and 1.8 M sodium carbonate aqueous solution (8 mL), the intermediate (5.0 g, 14.04 mmol) and 2-naphthaleneboronic acid (2.9 g, 16.8 mmol) were added, nitrogen was introduced to exhaust the air from the system, and bis(di-tert-butyl-4-dimethylaminophosphine)palladium chloride (0.018 g, 0.021 mmol) was added. The reaction was carried out at 85 °C for 5 h, 15 mL of deionized water was added, the mixture was extracted with ethyl acetate, dried over anhydrous magnesium sulfate, filtered, concentrated, and purified by column chromatography to obtain compound 3 (naphthyl spiropyran) having the structural formula shown in formula (1-3), 3.47 g of white crystals, and a yield of 61.3%.

[0038] Formula (1-3).

[0039] 2. Preparation of Photochromic Materials The specific preparation steps of the spiropyran photochromic epoxy resin material provided by the present invention are as follows: Epoxy resin A glue and B glue are mixed evenly in a mass ratio of 3:1 for later use; 4.0 mg of the previously prepared compound 3 is weighed and dissolved in 1 mL of dichloromethane to prepare a solution, poured into 25 g of epoxy resin glue, mixed evenly and poured into a mold, cured at room temperature for 24 hours, and the spiropyran photochromic epoxy resin material can be obtained after demolding.

[0040] Example 4 Synthesis of Compound 5 (Pyrenyl Spiropyran) 1. Preparation of naphthyl spiropyran Follow these steps: (1) Under light-shielding conditions, 1,2,3,3-tetramethyl-3H-indole iodide (5.0 g, 16.6 mmol), triethylamine (1.78 g, 17.52 mmol), and ethanol (60 mL) were added to a reaction flask in sequence. After nitrogen was introduced to exhaust the air, a solution of 4-bromo-2-hydroxybenzaldehyde (3.2 g, 16 mmol) in ethanol (15 mL) was added. The reaction was carried out at 80°C for 4 h. The system was cooled, filtered, washed with cold ethanol, and dried to obtain the intermediate as a white solid (4.15 g). The yield was 73%.

[0041] (2) After ultrasonicating a mixed solution of toluene (30 mL), ethanol (15 mL) and 2M sodium carbonate aqueous solution (5 mL) for 15 min, the intermediate (1.9 g, 5.6 mmol) and 1-pyreneboronic acid (1.8 g, 7.3 mmol) were added, and nitrogen was introduced to exhaust the air from the system. Then, bis(di-tert-butyl-4-dimethylaminophosphine)palladium chloride (0.015 g, 0.021 mmol) was added, and the reaction was carried out at 85 °C for 5 h. 20 mL of deionized water was added, and the mixture was extracted with ethyl acetate, dried over anhydrous sodium sulfate, filtered, concentrated, and purified by column chromatography to obtain compound 5 (pyrenyl spiropyran) having the structural formula shown in formula (1-5), 1.34 g of yellow crystals, and a yield of 50.2%.

[0042] Formula (1-5).

[0043] 2. Preparation of Photochromic Materials The specific preparation steps of the spiropyran photochromic epoxy resin material provided by the present invention are as follows: Epoxy resin A glue and B glue are mixed evenly in a mass ratio of 5:1 for use; 5.0 mg of the previously prepared compound 5 is weighed and dissolved in 2 mL of dichloromethane to prepare a solution, poured into 30 g of epoxy resin glue, mixed evenly and poured into a mold, cured at room temperature for 20 hours, and the spiropyran photochromic epoxy resin material can be obtained after demolding.

[0044] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0045] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A spiropyran derivative with color and fluorescence dual switching, which is a compound having a chemical structural formula (1): Formula (1), In formula (I), R is an aromatic group, selected from any one of phenyl, indenyl, naphthyl, fluorenyl, anthracenyl and pyrenyl.

2. The spiropyran derivative according to claim 1, characterized in that The spiropyran derivative is any one of the following compounds: Formula (1-1) Formula (1-2) Formula (1-3), Formula (1-4) Formula (1-5) Formula (1-6).

3. The method for preparing the spiropyran derivative according to claim 1 or 2, characterized in that: The steps include: Step 1: Under light-proof conditions and inert gas protection, add 4-bromo-2-hydroxybenzaldehyde, 1,2,3,3-tetramethyl-3H-indole iodide and triethylamine to an anhydrous ethanol solution, and fully react at 50-90°C to precipitate a solid to obtain an intermediate; Step 2: Under the protection of inert gas, the intermediate, phenylboronic acid derivative and bis(di-tert-butyl-4-dimethylaminophosphine)palladium chloride are added to a mixed solvent, the reaction temperature is 60-90°C, and after the reaction is completed, the spiropyran derivative is obtained by separation, extraction, drying and column chromatography; the phenylboronic acid derivative is one of phenylboronic acid, indeneboric acid, naphthaleneboric acid, fluoreneboric acid, anthraceneboric acid and pyreneboric acid; the mixed solvent is a mixed solvent of sodium carbonate or potassium carbonate solution, toluene and ethanol, or a mixed solvent of sodium carbonate or potassium carbonate solution, 1,4-dioxane and ethanol.

4. The preparation method according to claim 3, characterized in that: In step 1, the molar ratio of 4-bromo-2-hydroxybenzaldehyde to 1,2,3,3-tetramethyl-3H-indole iodide and triethylamine is 1: (0.9-1.1): (1.3-5), the reaction time is 2-18 hours, after the reaction is completed and the temperature is lowered, a solid is precipitated, filtered, washed, and dried to obtain an intermediate; In step 2, the molar ratio of the intermediate, the phenylboronic acid derivative and the bis(di-tert-butyl-4-dimethylaminophosphine)palladium chloride is 1:(1.1-3):(0.002-0.1), and the reaction time is 3-20 hours; The volume ratio of sodium carbonate / potassium carbonate solution: toluene: ethanol in the mixed solvent is 1: (10-100): (10-50), and the concentration of sodium carbonate / potassium carbonate solution is 0.5-20 M; The volume ratio of sodium carbonate / potassium carbonate solution: 1,4-dioxane: ethanol in the mixed solvent is 1: (10-100): (10-50).

5. A photochromic material, characterized in that: The spiropyran derivative according to claim 1 or 2 is mixed with an epoxy resin and then cured; the mass ratio of the spiropyran derivative to the epoxy resin is 1: (5000-10000).

6. The method for preparing the photochromic material according to claim 5, characterized in that: The steps include: Weigh a spiropyran derivative, dissolve it in an organic solvent to prepare a solution, pour it into an epoxy resin glue, mix it evenly, pour it into a mold, and solidify it into shape and demold it to obtain the product; The organic solvent is selected from dichloromethane, dichloroethane, tetrahydrofuran, N,N-dimethylformamide and methyl tert-butyl ether; the spiropyran derivative is prepared into a 0.0001-1 g / mL solution with the organic solvent.

7. The preparation method according to claim 6, characterized in that: The epoxy resin glue is obtained by mixing epoxy resin A glue and epoxy resin B glue in a mass ratio of 1-10:1; The epoxy resin A glue is at least one of bisphenol A epoxy resin, bisphenol F epoxy resin and hydrogenated bisphenol A epoxy resin; The epoxy resin B glue is an aliphatic polyamine.

8. The preparation method according to claim 7, characterized in that: The mass ratio of epoxy resin A glue and epoxy resin B glue is 3-5:1; The reaction solution is cured at room temperature for 10-30 hours.

9. The preparation method according to claim 7, characterized in that: The epoxy resin B glue is at least one of ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine and diethylaminopropylamine.

10. Use of the spiropyran derivative according to claim 1 or 2 or the photochromic material according to claim 5 in the preparation of two-dimensional optical display devices and intelligent molecular switches.

Images