A spiropyran derivative with color and fluorescence dual switch, a photochromic material and a preparation method and application thereof

Abstract

The application discloses a spiropyran derivative with color and fluorescence dual switch, a photochromic material and a preparation method and application thereof, the spiropyran derivative is a compound with a chemical structure general formula (1); and further discloses a photochromic material prepared by mixing the spiropyran derivative with an epoxy resin and a preparation method thereof. The aromatic fluorescent group is introduced into the side group of the spiropyran material, the conjugated system of the fluorescent group itself is large, and thus the fluorescence emission intensity after the spiropyran is opened is increased. The compound shows good photochromic and photoluminescent effects in organic solvents and solid media; the fluorescent group and the spiropyran material are combined, and a molecular switch material with significant color and fluorescence changes can be prepared; the spiropyran derivative can be used for preparing a two-dimensional optical display device and an intelligent material molecular switch.

Description

TECHNICAL FIELD

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

[0002] The fluorescent group is a kind of compound with fluorescence property as its name implies. The principle of light emission is that when irradiated by light, the compound absorbs energy into the excited state, and due to the extreme instability of the excited state, the compound immediately de-excites, at this time the energy is released in the form of light, so fluorescence is generated. The fluorescent group mostly has a multi-benzene ring structure, which can improve the conjugation effect of the whole system, thereby enhancing the fluorescence brightness of the system.

[0003] Spiropyran is a typical organic photochromic compound, which transforms from a closed ring spiropyran (SP) structure to an open ring merocyanine (MC) structure under ultraviolet light irradiation, and then the open ring body returns to the closed ring body under the action of visible light or heat. 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; in the open ring, the two rings change from the orthogonal type to the planar type, and the molecular conjugation effect is enhanced, at this time, the color, hydrophilicity, fluorescence, etc. of the spiropyran will change greatly. Therefore, researchers often use it as a molecular optical switch material and widely apply it in the fields of analytical chemistry, optical display devices, drug controlled release, etc. However, due to the relatively small molecular conjugation structure, it often leads to insufficient fluorescence brightness. SUMMARY

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present application is to propose a spiropyran derivative with color and fluorescence dual switch, which is a compound with the chemical structure general formula (1):

[0005] Formula (1);

[0006] In formula (I), R is an aromatic group, which is selected from any one of phenyl, indenyl, naphthyl, fluorenyl, anthryl, pyrenyl.

[0007] Preferably, the spiropyran derivative is any one of the following compounds:

[0008]

[0009] Formula (1-1) Formula (1-2) Formula (1-3)

[0010]

[0011] Formula (1-4) Formula (1-5) Formula (1-6).

[0012] Another object of the present application is to provide a preparation method of the above-mentioned spiropyran derivative, comprising the following steps:

[0013] Step one: under the conditions of light shielding and inert gas protection, 4-bromo-2-hydroxybenzaldehyde, 1,2,3,3-tetramethyl-3H-indole iodide and triethylamine are added into anhydrous ethanol solution, and the reaction is carried out at 50-90℃, and solid is precipitated to obtain an intermediate;

[0014] Step two: under the condition of inert gas protection, the intermediate, a benzene boronic acid derivative and bis (di-tert-butyl-4-dimethylaminophosphine) palladium chloride are added into a mixed solvent, the reaction temperature is 60-90℃, after the reaction is completed, liquid separation, extraction, drying and column chromatography are carried out to obtain the spiropyran derivative; the benzene boronic acid derivative is one of benzene boronic acid, indene boronic acid, naphthalene boronic acid, fluorene boronic acid, anthracene boronic acid and pyrene boronic 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.

[0015] Preferably, in step one, the molar ratio of 4-bromo-2-hydroxybenzaldehyde, 1,2,3,3-tetramethyl-3H-indole iodide and triethylamine is 1: (0.9-1.1) : (1.3-5), the reaction time is 2-18h, after the reaction is completed and the temperature is lowered, solid is precipitated, and the intermediate is obtained by suction filtration, washing and drying;

[0016] In step two, the molar ratio of the intermediate, the benzene boronic acid derivative and bis (di-tert-butyl-4-dimethylaminophosphine) palladium chloride is 1: (1.1-3) : (0.002-0.1), and the reaction time is 3-20h;

[0017] In the mixed solvent, the volume ratio of sodium carbonate / potassium carbonate solution : toluene : ethanol is 1: (10-100) : (10-50), and the concentration of sodium carbonate / potassium carbonate solution is 0.5-20 M;

[0018] In the mixed solvent, the volume ratio of sodium carbonate / potassium carbonate solution : 1,4-dioxane : ethanol is 1: (10-100) : (10-50).

[0019] Still another object of the present application is to provide a photochromic material, which is obtained by mixing and curing the spiropyran derivative according to any one of the above-mentioned spiropyran derivatives with an epoxy resin; the mass ratio of the spiropyran derivative to the epoxy resin is 1: (5000-10000).

[0020] Still another object of the present application is to provide the preparation method of the photochromic material as described above, comprising the following steps:

[0021] The spiro-pyrane derivative is weighed and dissolved in an organic solvent to form a solution, which is poured into an epoxy resin glue solution, mixed uniformly, and then poured into a mold, and after curing and demolding, the product is obtained.

[0022] The organic solvent is selected from dichloromethane, dichloroethane, tetrahydrofuran, N, N-dimethylformamide and methyl tert-butyl ether; and the spiro-pyrane derivative is prepared into a solution of 0.0001-1g / mL with the organic solvent.

[0023] Preferably, the epoxy resin glue solution is obtained by mixing epoxy resin A glue and epoxy resin B glue according to a mass ratio of 1-10:1.

[0024] The epoxy resin A glue is at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin and hydrogenated bisphenol A epoxy resin.

[0025] The epoxy resin B glue is an aliphatic polyamine.

[0026] Preferably, the epoxy resin A glue and the epoxy resin B glue are mixed according to a mass ratio of 3-5:1.

[0027] The reaction solution is cured at room temperature for 10-30 hours.

[0028] Preferably, the epoxy resin B glue is at least one of ethylenediamine, hexanediamine, diethylenetriamine, triethylenetetramine and diethylaminopropylamine.

[0029] The last object of the present application is to provide the application of the spiro-pyrane derivative or the photochromic material as described above in the preparation of two-dimensional optical display devices and intelligent molecular switches.

[0030] The synthesis path of the spiro-pyrane derivative of the present application is as follows:

[0031] The present application has the following advantages:

[0032] The present application provides a preparation method of a spiro-pyrane derivative with color and fluorescence dual switching, which has a simple process flow and high yield.

[0033] The present application introduces an aromatic fluorescent group into the side group of the spiro-pyrane material, and increases the fluorescence emission intensity after the ring opening of the spiro-pyrane through the large conjugated system of the fluorescent group itself. And the compound shows good photochromic and photoluminescent effects in organic solvents and solid media.

[0034] The molecular switch material with significant color and fluorescence change can be prepared by combining the fluorescent group and the spiropyran material; the spiropyran derivative of the application can be used for preparing two-dimensional optical display device and can be used for preparing intelligent material molecular switch. BRIEF DESCRIPTION OF DRAWINGS

[0035] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the following drawings, in which:

[0036] Figure 1 NMR spectrum of compound 6 in Example 2 of the present application.

[0037] Figure 2 UV absorption spectrum of compound 6 in dichloromethane before and after light irradiation in Example 2 of the present application.

[0038] Figure 3 Color change contrast chart of compound 6 in dichloromethane before and after light irradiation in Example 2 of the present application; wherein hv1 represents ultraviolet light of 295-395 nm, and hv2 represents visible light of 400-550 nm.

[0039] Figure 4 Color change contrast chart of compound 6 prepared in epoxy resin before and after light irradiation in Example 2 of the present application; wherein hv1 represents ultraviolet light of 295-395 nm, and hv2 represents visible light of 400-550 nm. DETAILED DESCRIPTION

[0040] The embodiments of the present application are described in detail below, and the embodiments described with reference to the accompanying drawings are exemplary.

[0041] The experimental methods in the following examples are all conventional methods, unless otherwise specified.

[0042] The main raw materials are as follows:

[0043] 4-bromo-2-hydroxybenzaldehyde: CAS No. 22532-62-3,

[0044] 1,2,3,3-tetramethyl-3H-indole iodide: CAS No. 5418-63-3,

[0045] bis (di-tert-butyl-4-dimethylaminophosphine) palladium chloride: CAS No. 34409-44-4,

[0046] triethylamine: CAS No. 121-44-8,

[0047] 9,9-dimethylfluorene-2-boronic acid: CAS No. 333432-28-3,

[0048] 9-anthraceneboronic acid: CAS No. 100622-34-2.

[0049] Example 1 Synthesis of compound 4 (anthracene-based spiropyran)

[0050] I. Preparation of anthracene-based spiropyran

[0051] The following steps are followed:

[0052] (1) Under light-proof conditions, 1, 2, 3, 3-tetramethyl-3H-indole iodide (6 g, 19.92 mmol), triethylamine (3 g, 29.78 mmol), ethanol (50 mL) were sequentially added to the reaction bottle, nitrogen was introduced to exhaust the air, then 4-bromo-2-hydroxybenzaldehyde (4 g, 19.92 mmol) ethanol (20 mL) solution was added, and the system was reacted at 80°C for 4h, the system was cooled, filtered, washed with cold ethanol, and dried to obtain 3.9 g of the intermediate as a white solid, with a yield of 55.1%.

[0053] (2) After ultrasonicating a mixed solution of toluene (15 mL), ethanol (9 mL) and 1.6M aqueous sodium carbonate 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, nitrogen was introduced to exhaust the air, then bis (di-tert-butyl-4-dimethylaminophosphine) palladium chloride (0.01 g, 0.014 mmol) was added, and the system was reacted at 80°C for 3h, 15 mL of deionized water was added, extraction was performed with ethyl acetate, anhydrous magnesium sulfate was added for drying, filtration was performed, and after concentration, column chromatography was performed to obtain compound 4 (anthracene-based spiropyran) with a structure as shown in formula (1-4), which was a white solid, with a yield of 0.35 g, 45.8%.

[0054] Formula (1-4).

[0055] II. Preparation of photochromic material

[0056] The specific preparation steps of the spiropyran photochromic epoxy resin material provided by the present application are as follows:

[0057] Epoxy resin A glue and B glue were stirred uniformly at a mass ratio of 3:1 for standby use; 3.0 mg of the prepared compound 4 was dissolved in 1 mL of dichloromethane to prepare a solution, which was poured into 30 g of epoxy resin glue liquid, and after uniform mixing, it was poured into a mold, and cured at room temperature for 24 hours, and after demolding, the spiropyran photochromic epoxy resin material was obtained.

[0058] Example 2 Synthesis of compound 6 (fluorene-based spiropyran)

[0059] I. Preparation of fluorene-based spiropyran

[0060] The following steps are followed:

[0061] (1) 1,2,3,3-tetramethyl-3H-indolium iodide (4.7 g, 15.67 mmol), triethylamine (2.26 g, 22.38 mmol), ethanol (50 mL) were added into a reaction flask under light-protected condition, and nitrogen was introduced to remove air. Then, 4-bromo-2-hydroxybenzaldehyde (3 g, 14.92 mmol) in ethanol (10 mL) was added, and the mixture was reacted at 80°C for 4 h. After the system was cooled, filtration was performed, and the product was washed with cold ethanol and dried to obtain an intermediate in the form of a white solid (3.7 g, yield 69.6%).

[0062] (2) A mixture of toluene (20 mL), ethanol (12 mL) and 1.6 M aqueous sodium carbonate solution (5 mL) was ultrasonically treated for 15 min, and then the intermediate (1.0 g, 2.81 mmol) and 9,9-dimethylfluorene-2-boronic acid (0.87 g, 3.65 mmol) were added. After nitrogen was introduced to remove air, bis (di-tert-butyl-4-dimethylaminophosphine) palladium chloride (0.015 g, 0.021 mmol) was added, and the mixture was reacted at 80°C for 4 h. Then, 15 mL of deionized water was added, and extraction was performed with ethyl acetate. After drying over anhydrous magnesium sulfate, filtration was performed, and the product was concentrated and purified by column chromatography to obtain compound 6 (fluorenyl spiropyran) in the form of a yellow crystal as shown in formula (1-6) (0.72 g, yield 54.6%).

[0063] Formula (1-6).

[0064] The nuclear magnetic resonance hydrogen spectrum of compound 6 was detected as follows: 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).

[0065] The nuclear magnetic spectrum and ultraviolet absorption spectrum of compound 6 are shown in Figure 1 、 2 The color change contrast chart of compound 6 before and after light irradiation in dichloromethane is shown in Figure 3 .

[0066] II. Preparation of photochromic material

[0067] The specific preparation steps of the spiropyran photochromic epoxy resin material provided by the present application are as follows:

[0068] The epoxy resin A glue and the epoxy resin B glue are stirred uniformly at a mass ratio of 4:1 for standby; 5.0 mg of the prepared compound 6 is dissolved in 1 mL of dichloromethane to prepare a solution, which is poured into 40 g of the epoxy resin glue liquid, and then poured into a mold after being uniformly mixed, and cured at room temperature for 20 hours, and the spiropyran photochromic epoxy resin material can be obtained after demolding. Figure 4 The color change contrast chart of the prepared photochromic epoxy resin material before and after light irradiation is shown in the figure, wherein hv1 represents ultraviolet light of 295-395 nm, and hv2 represents visible light of 400-550 nm.

[0069] Example Three Synthesis of compound 3 (naphthyl spiropyran)

[0070] I. Preparation of naphthyl spiropyran

[0071] The following steps are followed:

[0072] (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) are sequentially added to a reaction bottle, nitrogen is introduced to exhaust air, then 4-bromo-2-hydroxybenzaldehyde (6.6 g, 33 mmol) is added to ethanol (30 mL) solution, and the system is reacted at 85°C for 6 h, the system is cooled, filtered, washed with cold ethanol, and dried to obtain an intermediate as a white solid 7.6 g, with a yield of 65%.

[0073] (2) After the mixture of toluene (30 mL), ethanol (25 mL), and 1.8M sodium carbonate aqueous solution (8 mL) is ultrasonically treated for 10 min, the intermediate (5.0 g, 14.04 mmol) and 2-naphthalene boronic acid (2.9 g, 16.8 mmol) are added, nitrogen is introduced to exhaust air, then bis(di-tert-butyl-4-dimethylaminophosphine) palladium chloride (0.018 g, 0.021 mmol) is added, the system is reacted at 85°C for 5 h, 15 mL of deionized water is added, extraction is performed with ethyl acetate, anhydrous magnesium sulfate is added for drying, filtration is performed, and after concentration, column chromatography is performed to obtain compound 3 (naphthyl spiropyran) with a structure as shown in formula (1-3), which is a white crystal 3.47 g, with a yield of 61.3%.

[0074] Formula (1-3).

[0075] II. Preparation of photochromic material

[0076] The specific preparation steps of the spiropyran photochromic epoxy resin material provided by the present application are as follows:

[0077] The epoxy resin A glue and the epoxy resin B glue are stirred uniformly at a mass ratio of 3:1 for standby use; 4.0 mg of the compound 3 prepared in the foregoing is dissolved in 1 mL of dichloromethane to prepare a solution, which is poured into 25 g of the epoxy resin glue liquid, and then uniformly mixed and poured into a mold, and cured at room temperature for 24 hours, and then demolded to obtain the spiropyran photochromic epoxy resin material.

[0078] Example Four Synthesis of Compound 5 (pyrene-based spiropyran)

[0079] I. Preparation of naphthyl spiropyran

[0080] The following steps are followed:

[0081] (1) Under light-proof 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) are sequentially added to a reaction bottle, nitrogen is introduced to exhaust air, then 4-bromo-2-hydroxybenzaldehyde (3.2 g, 16 mmol) is added in ethanol (15 mL), and the system is reacted at 80°C for 4 h, the system is cooled, filtered, washed with cold ethanol, and dried to obtain an intermediate as a white solid 4.15 g, with a yield of 73%.

[0082] (2) After the mixture of toluene (30 mL), ethanol (15 mL), and 2M sodium carbonate aqueous solution (5 mL) is ultrasonically treated for 15 min, the intermediate (1.9 g, 5.6 mmol) and 1-pyreneboronic acid (1.8 g, 7.3 mmol) are added, nitrogen is introduced to exhaust air, then bis(di-tert-butyl-4-dimethylaminophosphine) palladium chloride (0.015 g, 0.021 mmol) is added, the system is reacted at 85°C for 5 h, 20 mL of deionized water is added, extraction is performed with ethyl acetate, anhydrous sodium sulfate is used for drying, filtration is performed, and after concentration, column chromatography is performed to obtain compound 5 (pyrene-based spiropyran) with a structure as shown in formula (1-5), yellow crystals 1.34 g, with a yield of 50.2%.

[0083] Formula (1-5).

[0084] II. Preparation of photochromic material

[0085] The specific preparation steps of the spiropyran photochromic epoxy resin material provided by the present application are as follows:

[0086] The epoxy resin A glue and B glue are stirred uniformly with a mass ratio of 5:1 for standby use; 5.0 mg of the compound 5 prepared in the foregoing is dissolved in 2 mL of dichloromethane to prepare a solution, which is poured into 30 g of the epoxy resin glue liquid, mixed uniformly, and then poured into a mold, and cured at room temperature for 20 hours to obtain a spiropyran photochromic epoxy resin material.

[0087] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example.

[0088] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A spiropyran derivative with dual color and fluorescence switching, which is a compound having the general chemical formula (1): Equation (1).

2. The method for preparing the spiropyran derivative according to claim 1, characterized in that, Includes the following steps: Step 1: Under light-protected conditions and inert gas protection, 4-bromo-2-hydroxybenzaldehyde, 1,2,3,3-tetramethyl-3H-indole iodide, and triethylamine are added to anhydrous ethanol solution and reacted completely at 50~90℃ to precipitate a solid and obtain an intermediate. Step 2: Under inert gas protection, the intermediate, fluorenboric acid, and bis(di-tert-butyl-4-dimethylaminophosphine)palladium chloride are added to a mixed solvent. The reaction temperature is 60-90℃. After the reaction is completed, the spiropyran derivative is obtained by separation, extraction, drying, and column chromatography. The mixed solvent is a mixture of sodium carbonate or potassium carbonate solution with toluene and ethanol, or a mixture of sodium carbonate or potassium carbonate solution with 1,4-dioxane and ethanol.

3. The preparation method according to claim 2, characterized in that: In step one, 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 2~18h, after the reaction is completed and the temperature is lowered, the solid precipitates, and after filtration, washing and drying, the intermediate is obtained; In step two, the molar ratio of the intermediate, fluorenboric acid, and bis(di-tert-butyl-4-dimethylaminophosphine)palladium chloride is 1 : (1.1~3) : (0.002~0.1), and the reaction time is 3~20 h; 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).

4. A photochromic material, characterized in that: It is obtained by mixing and curing the spiropyran derivative described in claim 1 with epoxy resin; the mass ratio of spiropyran derivative to epoxy resin is 1:(5000-10000).

5. The method for preparing the photochromic material according to claim 4, characterized in that, Includes the following steps: Weigh out the spiropyran derivative, dissolve it in an organic solvent to prepare a solution, pour it into the epoxy resin liquid, mix it evenly, pour it into a mold, cure and demold 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 solution of 0.0001-1 g / mL using the organic solvent.

6. The preparation method according to claim 5, characterized in that: The epoxy resin adhesive is obtained by mixing epoxy resin A and epoxy resin B in a mass ratio of 1-10:1; The epoxy resin A is at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin and hydrogenated bisphenol A epoxy resin; The epoxy resin B is an aliphatic polyamine.

7. The preparation method according to claim 6, characterized in that: The mass ratio of epoxy resin A to epoxy resin B is 3-5:1; The reaction solution is cured at room temperature for 10-30 hours.

8. The preparation method according to claim 6, characterized in that: The epoxy resin B is at least one of ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, and diethylaminopropylamine.

9. The application of the spiropyran derivative of claim 1 or the photochromic material of claim 4 in the preparation of two-dimensional optical display devices and smart molecular switches.

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