CN110407718B - Benzimide Derivatives Using Triphenylamine as Donor and Their Preparation and Application - Google Patents

Abstract

The invention provides a benzoyl imide derivative (I) taking triphenylamine as a donor, a preparation method thereof and application thereof in preparing a piezochromic material. The novel benzoyl imide derivative is used as a luminescent material, and the light color conversion from green to yellow and from blue to yellow can be respectively obtained by grinding two crystals of the novel benzoyl imide derivative, and the novel benzoyl imide derivative has the following beneficial effects: the preparation method is simple, and the material has excellent piezochromic property.

Description

Benzimide Derivatives Using Triphenylamine as Donor and Their Preparation and Application

(1) Technical field

The invention relates to a benzimide derivative using triphenylamine as a donor, a preparation method thereof and its application in preparing a piezochromic material.

(2) Background technology

Organic stimuli-responsive materials refer to organic materials whose physical properties (such as color, luminescence, etc.) change after being affected by external environmental factors (such as temperature, pressure, solvent, pH, etc.). Among them, piezochromic materials have been extensively studied in recent years. Piezochromism refers to the phenomenon that the fluorescent color of a material will change under the action of external force. Materials with piezochromic properties show unprecedented application potential in many fields such as anti-counterfeiting identification and chemical sensing. Therefore, the research and development of piezochromic materials has important theoretical significance and practical application value.

As a strong electron-donating group, triphenylamine is often used in the construction of light-emitting molecules. Due to the existence of oxygen and nitrogen atoms, benzoimide derivatives are prone to form weak interactions such as hydrogen bonds between molecules, resulting in their variable aggregated structures, which are just conducive to their piezochromic properties. The novel benzoimide derivatives constructed with triphenylamine as the donor are of great significance for promoting the development of piezochromic luminescent materials.

(3) Contents of the invention

The purpose of the present invention is to provide a novel benzimide derivative using triphenylamine as a donor, a preparation method thereof, and its application in the preparation of piezochromic materials.

The technical scheme adopted in the present invention is:

A kind of benzimide derivatives with triphenylamine as donor, the structure is shown in formula (I):

The present invention also relates to a method for preparing the benzimide derivatives, the method comprising: dissolving the compound represented by the formula (II) in dichloromethane, irradiating the reaction solution with a 365nm ultraviolet lamp for 5-7 days, The benzimide derivatives are obtained by separation and purification; the amount of dichloromethane should at least dissolve all the reactants.

The separation and purification method is as follows: the reaction solution is successively extracted with dichloromethane and deionized water, the organic phases are combined, dried by adding MgSO ₄ , concentrated under reduced pressure, and separated and purified by column chromatography to obtain the yellow solid target product, which is the benzene Carboximide derivatives;

During the column chromatography separation, the stationary phase is 300-400 mesh silica gel, and the mobile phase is a mixed solvent with a volume ratio of petroleum ether:ethyl acetate of 3:1.

The compound of formula (II) is prepared by the following method: under nitrogen protection, 4-fluoroaniline, benzil, diphenylaminobenzaldehyde and amine acetate are dissolved in an acetic acid solvent, and the reaction solution is heated and refluxed for 10 to 18 hours. The compound of formula (II) is obtained through separation and purification.

The separation and purification method is as follows: after the reaction solution is cooled, deionized water is added to separate out a white solid, filtered, the filter residue is extracted with dichloromethane and deionized water successively, the organic phases are combined, dried by adding MgSO ₄ , concentrated under reduced pressure, and subjected to column chromatography. Separation and purification to obtain a white solid target product, which is the compound of formula (II).

The amount ratio of the 4-fluoroaniline, benzil, dianilinobenzaldehyde and amine acetate is 1-5:1:1-1.2:1-4. The added amount of the acetic acid is suitable to just dissolve all the reactants.

During the column chromatography separation, the stationary phase is 300-400 mesh silica gel, and the mobile phase is a mixed solvent with a volume ratio of ethyl acetate:dichloromethane of 1:200.

The present invention also relates to the application of the benzimide derivatives in the preparation of piezochromic materials.

The compound (I) obtained above is dissolved in mixed solvents of ethanol and water in different proportions, and crystals are grown after the solvent is slowly volatilized. Two luminescent crystals, green and blue, were obtained, named 1a and 1b, respectively.

Further grinding 1a and 1b with a mortar can change the color of their emission, 1a from green to yellow, 1b from blue to yellow.

The beneficial effects of the present invention are mainly reflected in: the present invention provides a new benzimide derivative that can be used as a piezochromic material, the preparation method is simple, and the material has excellent piezochromic properties.

(4) Description of drawings

Fig. 1 is a fluorescence emission spectrum diagram of the compound (I) of the present invention.

FIG. 2 is an emission spectrum diagram of the crystal 1a of the present invention with different grinding degrees.

FIG. 3 is an emission spectrum diagram of the crystal 1b of the present invention with different grinding degrees.

(5) Specific implementation methods

The present invention is further described below in conjunction with specific embodiment, but the protection scope of the present invention is not limited to this:

Example 1: Synthesis of Compound (II)

Under nitrogen protection, 4-fluoroaniline (111 mg, 10 mmol), benzil (420 mg, 2 mmol), dianilinobenzaldehyde (546.66 mg, 2 mmol), and amine acetate (617 mg, 8 mmol) were dissolved in acetic acid (15 mL) In the solvent, the system was refluxed for 14 hours. After the system was cooled, deionized water was added, and a large amount of white solid was precipitated. After filtration, the obtained white solid was extracted with dichloromethane and deionized water, and the organic phases _were combined. Then use column chromatography to separate and purify, the stationary phase is 300-400 mesh silica gel, the mobile phase is a mixed solvent of ethyl acetate:dichloromethane=1:150-200, and finally 500 mg of white solid target product (II) is obtained in a yield of 500 mg. was 46%.

Compound (II) ¹ H NMR data: (500MHz, DMSO) δ 7.50-7.46 (m, 2H), 7.36 (dt, J=9.0, 3.5Hz, 2H), 7.32 (dt, J=5.2, 2.2Hz, 6H), 7.30–7.22 (m, 6H), 7.22–7.15 (m, 4H), 7.09 (t, J=7.4Hz, 2H), 7.03 (dd, J=8.5, 1.0Hz, 4H), 6.85–6.80 (m, 2H). MS (ESI) theoretical m/z: 557.23, found: 559.1 (M ⁺ ).

Example 2: Synthesis of Compound (I)

The compound obtained in Example 1 (100 mg, 0.18 mmol) was dissolved in a dichloromethane (100 mL) solvent and irradiated under a UV lamp at 365 nm for 7 days. After the reaction is completed, extract with dichloromethane and deionized water, combine the organic phases, add anhydrous MgSO ₄ to dry the obtained organic phase, concentrate under reduced pressure, and then separate and purify by column chromatography. The stationary phase is 300-400 mesh silica gel. The phase is a mixed solvent of petroleum ether:ethyl acetate=3:1, and finally 42 mg of the target yellow solid is obtained with a yield of 42%.

Compound (I) ¹ H NMR data: (500 MHz, Tol) δ 7.89 (d, J=3.5 Hz, 1H), 7.79 (d, J=7.4 Hz, 1H), 7.55 (dd, J=11.2, 8.3 Hz) ,1H),7.10(s,5H),7.05-6.95(m,12H),6.92(dd,J=8.9,5.6Hz,3H),6.89-6.82(m,3H),6.73(t,J=5.8 Hz, 1H), 6.42 (t, J=8.5Hz, 1H). MS (ESI) theoretical value m/z: 589.22, measured value: 591.5 (M ⁺ ).

Example 3: Crystal Growth of Crystals 1a, 1b

The compounds obtained in Example 2 were dissolved in mixed solutions of different ratios of ethanol and water (1:1, 2:1, 3:1, 4:1, 5:1), and the solvent was slowly volatilized at room temperature. , crystals with green and blue fluorescence grow, 1a and 1b, respectively.

Example 4: Emission Spectra of Crystals 1a, 1b and Piezochromic Spectra of Crystals

The crystals 1a and 1b obtained in Example 3 were subjected to solid fluorescence emission spectra, and their characteristic fluorescence emission spectra were obtained, as shown in FIG. 1 , and it was confirmed that they had photoluminescence properties. Substances 1a and 1b have emission peaks at 448 nm and 497 nm, respectively.

The crystals 1a and 1b obtained in Example 3 were subjected to fluorescence emission spectra of different solids in a mortar to obtain their characteristic fluorescence emission spectra, as shown in Figure 2, confirming their piezochromic properties. The emission peaks of substances 1a and 1b range from 495 nm to 544 nm and 451 nm to 547 nm, respectively.

Claims (9)

1. a kind of benzimide derivatives with triphenylamine as donor, structure is shown in formula (I):

2. The method for preparing the benzimide derivative according to claim 1, the method comprising: dissolving the compound represented by formula (II) in dichloromethane, and after irradiating a 365nm ultraviolet lamp for 5 to 7 days, reacting The liquid is separated and purified to obtain the benzimide derivatives;

3. method as claimed in claim 2, it is characterized in that described separation and purification method is as follows: reaction solution is successively extracted with dichloromethane and deionized water, merge organic phase, add MgSO ₄ dry, concentrate under reduced pressure, column chromatography Separate and purify to obtain yellow solid target product, which is the benzimide derivative; 4. The method according to claim 3, characterized in that during the separation by column chromatography, the stationary phase is 300-400 mesh silica gel, and the mobile phase is a mixed solvent of petroleum ether:ethyl acetate volume ratio 3:1. 5. method as claimed in claim 2 is characterized in that described formula (II) compound is obtained by following method: under nitrogen protection, by 4-fluoroaniline, benzil, dianilino benzaldehyde and acetic amine It is dissolved in acetic acid solvent, heated and refluxed for 10-18 hours, and the reaction solution is separated and purified to obtain the compound of formula (II). 6. method as claimed in claim 5 is characterized in that described separation and purification method is as follows: add deionized water after reaction liquid is cooled, separate out white solid, filter, filter residue is successively extracted with dichloromethane and deionized water, merge organic phase, adding MgSO ₄ to dry, concentrating under reduced pressure, and separating and purifying by column chromatography to obtain a white solid target product, which is the compound of formula (II). 7. method as claimed in claim 5 is characterized in that the ratio of the amount of described 4-fluoroaniline, benzil, diphenylamino benzaldehyde and amine acetate substance is 1～5:1:1～1.2:1 ~4. 8. The method according to claim 6, characterized in that, during the separation by column chromatography in the process of preparing the compound of formula (II), the stationary phase is 300-400 mesh silica gel, and the mobile phase is ethyl acetate: dichloromethane Mixed solvents with a volume ratio of 1:200. 9. The application of the benzimide derivatives of claim 1 in the preparation of piezochromic materials.

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