An anthracene diphenyl ether compound with AIE properties, its preparation method and application

Abstract

This invention discloses an anthracene diphenyl ether compound with AIE properties, its preparation method, and its applications. The anthracene diphenyl ether compound with AIE properties is 9,10-bis(di(4-phenyletheryl)vinyl)-9,10-dihydroanthracene. This compound exhibits excellent AIE effects, with improved fluorescence emission intensity compared to existing fluorescent detection substances. It shows a fluorescence enhancement response to Trp that differs from other amino acids, specifically recognizing tryptophan without being affected by other amino acids. The detection luminescence effect is significant, with good sensitivity and a low detection limit. Furthermore, the short response time allows for instantaneous response to Trp, greatly shortening the detection time and effectively improving work efficiency. Experimental results show that the fluorescence emission intensity of the compound reaches 2490 nm, the detection limit for specific recognition of tryptophan is 89.35 nM, and the sensitivity (Ksv) is 9300 M. ‑1 .

Description

Technical Field

[0001] This invention belongs to the field of aggregation-induced enhanced luminescence (AIE) materials, and particularly relates to an anthracene diphenyl ether compound with AIE properties, its preparation method, and its application. Background Technology

[0002] Most organic light-emitting molecules emit strong fluorescence in dilute solutions, but their fluorescence disappears in concentrated solutions. This aggregation-induced quenching (ACQ) effect limits the application of light-emitting molecules in materials science. In 2001, Tang Benzhong's research group discovered a molecule with a completely different property from the traditional aggregation-induced quenching (ACQ) property. The luminogen does not emit light in solution, but exhibits strong fluorescence in the aggregated state, leading to the concept of aggregation-induced emission (AIE). Compounds with AIE properties possess many attractive advantages, such as good biocompatibility, high resolution, strong photobleaching resistance, low cytotoxicity, and ease of functionalization, and have been widely used in cell tracking, sensors, drug delivery, fluorescence imaging, and clinical medicine.

[0003] Tryptophan is an essential amino acid required by the human body. It plays a vital role in preventing pellagra and depression, improving sleep, and regulating mood. It is widely used in the food, pharmaceutical, and feed additive industries. The analysis and determination of tryptophan is of great significance in the fields of biology, medicine, and chemistry. Currently, the main methods for determining tryptophan include spectrophotometry, fluorescence methods, high-performance liquid chromatography, capillary electrophoresis, atomic absorption spectrometry, and electrochemical methods. However, each method has its limitations: such as requiring specific instruments or trained personnel, inconvenient operation, high analytical costs, slow testing speed, and high detection limits. Summary of the Invention

[0004] In order to solve the above-mentioned technical problems existing in the prior art, the present invention provides an anthracene diphenyl ether compound with AIE properties, a preparation method and applications.

[0005] The technical solution of this invention is: an anthracene diphenyl ether compound with AIE properties, namely 9,10-bis(di(4-phenyletheryl)vinyl)-9,10-dihydroanthracene, with the following structural formula:

[0006] .

[0007] The preparation method of the anthracene diphenyl ether compound with AIE properties is as follows:

[0008] .

[0009] The preparation method of the anthracene diphenyl ether compound with AIE properties includes the following specific steps:

[0010] Step 1. Add 4-phenyletherylphenylboronic acid, 9,10-bis(dibromomethylene)-9,10-dihydroanthracene, anhydrous potassium carbonate, and Pd(PPh3)4 to a two-necked flask containing a magnetic stir bar; weigh 1,4-dioxane and distilled water as reaction solvents, pour them into the two-necked flask, and magnetically stir until all the reactants are dissolved; the ratio of 4-phenyletherylphenylboronic acid, compound 6, anhydrous potassium carbonate, Pd(PPh3)4, 1,4-dioxane, and distilled water is 3.36 mmol:0.674 mmol:6.51 mmol:0.174 mmol:120 mL:24 mL;

[0011] Step 2. Under a nitrogen atmosphere, after three vacuum cycles, the reaction mixture was heated to 90 °C in an oil bath for 24 h. Then, the heating was stopped and the reactants were cooled to room temperature. The mixture was extracted with 90 mL of dichloromethane and then washed with saturated brine.

[0012] Step 3. Collect the lower oily mixture and dry it with anhydrous sodium sulfate for 1 hour;

[0013] Step 4. The crude product was obtained by vacuum filtration and rotary evaporation under reduced pressure. It was then purified by column chromatography using petroleum ether / dichloromethane at a volume ratio of 5:1 as the eluent. Ethanol was then added and recrystallized to obtain a green powder.

[0014] The above-mentioned anthracene diphenyl ether compounds with AIE properties are used as fluorescent probes for recognizing small molecules, specifically as fluorescent probes for recognizing tryptophan.

[0015] The anthracene diphenyl ether compounds prepared in this invention exhibit excellent AIE (Alternating Electron Emission) characteristics. Their fluorescence emission intensity is improved compared to existing fluorescent detection substances, and they show a fluorescence enhancement response to Trp that differs from other amino acids. They specifically recognize tryptophan without being affected by other amino acids, demonstrating significant luminescence effects, good sensitivity, and a low detection limit. Furthermore, their short response time allows for instantaneous response to Trp, greatly reducing the detection time and effectively improving work efficiency. Experimental results show that the fluorescence emission intensity of the compounds in this invention reaches 2490 nm, the detection limit for specific tryptophan recognition is 89.35 nM, and the sensitivity (Ksv) is 9300 M. -1 . Attached Figure Description

[0016] Figure 1 It is the compound prepared in Example 1 of this invention. 1 H NMR spectrum.

[0017] Figure 2 This is a fluorescence spectrum of the compound prepared in Example 1 of this invention with the addition of different amino acids.

[0018] Figure 3 This is a three-dimensional diagram showing the interaction between the compound prepared in Example 1 of this invention as a fluorescent probe and different types of amino acids at different concentration gradients.

[0019] Figure 4 The images show the fluorescence and ultraviolet absorption spectra of the compound prepared in Example 1 of this invention as a fluorescent probe in titration experiments with different concentrations of Trp.

[0020] Figure 5 This is a Stern-Volmer curve and linear relationship graph of the compound prepared in Example 1 of the present invention at different Trp concentrations.

[0021] Figure 6 The image shows the fluorescence spectrum of the compound prepared in Example 1 of this invention as a fluorescent probe in an experiment involving interference from other amino acids and Trp.

[0022] Figure 7 These are the fluorescence spectra of the compounds prepared in Example 1 of this experiment for different response times to Trp.

[0023] Figure 8 This is a Job's curve of the compound prepared in Example 1 of this invention. Detailed Implementation

[0024] The present invention is described in detail below through specific embodiments, but this does not limit the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can all be obtained commercially.

[0025] The method for preparing the anthracene diphenyl ether compound with AIE properties of the present invention is carried out in sequence according to the following steps:

[0026] Step 1. Weigh 4-phenyletherylphenylboronic acid (0.72 g, 3.36 mmol), 9,10-bis(dibromomethylene)-9,10-dihydroanthracene (0.3 g, 0.674 mmol), anhydrous potassium carbonate (0.9 g, 6.51 mmol), and Pd(PPh3)4 (0.12 g, 0.174 mmol) and add them to a two-necked flask containing a magnetic stir bar; weigh 1,4-dioxane (120 ml) and distilled water (24 ml) as reaction solvents using a graduated cylinder, pour them into the two-necked flask, and magnetically stir until all the reactants are dissolved;

[0027] Step 2. Under a nitrogen atmosphere, after three vacuum cycles, the oil bath is heated to 90 °C to start the Suzuki coupling reaction. The reaction is allowed to proceed for 24 h. Then, the heating is stopped and the reactants are cooled to room temperature. The mixture is extracted three times with 90 mL of dichloromethane and washed with saturated brine after each extraction.

[0028] Step 3. Collect the lower oily mixture, add an appropriate amount of anhydrous sodium sulfate and dry for 1 hour;

[0029] Step 4. The crude product was obtained by vacuum filtration and rotary evaporation under reduced pressure. It was then purified by column chromatography using petroleum ether / dichloromethane (5 / 1, v / v) as the eluent. A suitable amount of ethanol was added and the product was recrystallized to obtain 0.4 g of green powder, with a yield of 74.8%.

[0030] The compound 1 H NMR spectrum as follows Figure 1 As shown, the structural formula is as follows:

[0031] .

[0032] Experiment 1: AIE performance test of anthracene diphenyl ether compounds.

[0033] To demonstrate the AIE effect of this compound, it was dissolved in tetrahydrofuran (THF) to prepare a solution. THF was used as a benign solvent and water as a poor solvent. The compound's concentration in its solution (10⁻⁶) was measured. -4 The fluorescence intensity in (mol / L) was determined. The excitation wavelength of the fluorescence spectrum was set to 300 nm, the slit width to 10:10, and the voltage to 550 V. By changing the volume fraction of water, (f w Absorption and emission spectra were obtained from 0% to 90% in a THF / H2O mixture, and the intensity change of the solution (fw) from 0% to 90% was observed visually under a UV lamp (365 nm).

[0034] Experiments show that the fluorescence intensity of the compound in pure THF solution is 20.97. When the water content increases to 60%, the fluorescence quantum yield is 41%, and the fluorescence intensity reaches a maximum of 2490, which is 118.75 times higher than that in pure THF solution. Correspondingly, the emission wavelength blue shifts from 474.4 nm to 472 nm, and the absorbance decreases from 3.5 to 1.0.

[0035] The above data indicate that this compound exhibits typical AIE characteristics and belongs to the category of AIE-property compounds.

[0036] Experiment 2: Selectivity of anthracene diphenyl ethers for amino acids

[0037] To confirm the specific recognition of amino acids by this compound, the compound prepared in Example 1 of this invention was used as a fluorescent probe to interact with different amino acids. Specifically, 2 ml of the compound was added to 100 μM of 12 amino acids (Val, Thr, Ccp, Ala, Leu, Met, Pro, Ser, Cys, Lys, Glu, Trp). The fluorescence spectra are shown below. Figure 2As shown. From Figure 2 It can be seen that only when 100 μMTrp is added does the compound exhibit a blue shift and a drastic change in fluorescence intensity. Under the same conditions, the addition of other amino acids in equal amounts results in only slight changes in fluorescence intensity, remaining essentially unchanged compared to the case without added amino acids. The drastic change in fluorescence intensity when tryptophan is added alone indicates the specific recognition of tryptophan by this compound.

[0038] Experiment 3: Fluorescent Titration Test of Amino Acids

[0039] The compound prepared in Example 1 of this invention was used as a fluorescent probe to interact with different types of amino acids at different concentration gradients. Specifically, 2 ml of the compound was taken, and 0-100 μM of the aforementioned 12 amino acids were added sequentially for fluorescent titration testing. The three-dimensional image is shown below. Figure 3 As shown. By Figure 3 It can be seen that the fluorescence intensity of this compound increases dramatically with the increase of Trp concentration, while the fluorescence intensity remains almost unchanged as the concentrations of other amino acids gradually increase. Only the addition of Ccp, Ala, and Val amino acids shows a slight increasing trend.

[0040] Experiment 4: Titration of Tryptophan Concentration

[0041] Using the compound prepared in Example 1 of this invention as a fluorescent probe, titration experiments were conducted on different concentrations of Trp. Specifically, 0-100 μM Trp was added sequentially to the compound, and fluorescence emission and ultraviolet absorption spectra were obtained, as shown below. Figure 4 As shown in the figure, the fluorescence emission spectra show that the emission wavelengths of all compounds undergo a significant blue shift and the fluorescence intensity increases dramatically; the ultraviolet absorption spectra show that the absorbance of all compounds decreases.

[0042] Experiment 5: Sensitivity and detection limit for Trp

[0043] The formula for calculating the detection limit of a compound is: detection limit = 3σ / k;

[0044] Where σ is the standard deviation of the blank compound measurement, and k is the slope of the linear relationship between fluorescence intensity and Trp concentration. The linear relationship graph of the compound is shown below. Figure 5 As shown, the correlation coefficient R of the compounds 2 The value is 0.98005, indicating a good linear relationship. The value of k is 61.88, and the corresponding detection limit is calculated to be 89.35 nM using σ.

[0045] To investigate compound detection

[0046] Where I0 is the initial fluorescence intensity of the added compound, I is the corresponding fluorescence intensity when different concentrations of Trp are added, and [Q] is the molar concentration of Trp. The Stern-Volmer curve is shown below. Figure 5 As shown, the correlation coefficient R of the compounds 2 The value is 0.98793, indicating a good linear relationship. The sensitivity (Ksv) is 9300 MHz. -1 The compound has high sensitivity, and therefore responds well to tryptophan.

[0047] Experiment 6: Interference Experiment

[0048] To investigate whether the presence of other amino acids would affect the detection of tryptophan by the compound of this invention, an interference experiment was conducted using the compound prepared in Example 1 of the invention as a fluorescent probe against other amino acids and Trp. Specifically, 10 μM of other amino acids and tryptophan were added alternately, and their fluorescence intensity was measured (twice for each). The results are as follows: Figure 6 As shown in the figure. Experimental results show that the fluorescence intensity changes only slightly when other amino acids are added, while it increases rapidly when tryptophan is added. Repeated addition of 10 μM of other amino acids also has no significant effect on the fluorescence intensity. This demonstrates that the compound in this invention is not affected by other amino acids when detecting tryptophan, and can specifically recognize tryptophan. The addition of equal amounts of other amino acids has virtually no impact on the fluorescence intensity, and the trends are similar.

[0049] Experiment 7: Response Time Test

[0050] To investigate the fluorescence intensity of the compound in response to Trp at different response times, this experiment used a Trp solution with a maximum titration concentration of 100 μM, which was directly added to the compound. The fluorescence spectrum is shown below. Figure 7 As shown in the figure, the results indicate that the fluorescence intensity of the solution increases rapidly immediately upon the addition of Trp to the compound, and then the change in fluorescence intensity becomes weak with increasing response time. This demonstrates that this compound can provide an instantaneous response to Trp, greatly shortening the detection time of Trp and improving work efficiency.

[0051] Experiment 8: Job's Curve Analysis

[0052] To investigate the optimal binding ratio of the compound to Trp, Job's curves were used. The total concentration of the compound and Trp was controlled at 100 μM, thus varying the ratio of the compound to Trp. Figure 8 Linear fitting revealed that the fluorescence intensity of the [compounds] / [compounds+Trp] combination was highest at around 0.5, indicating that the compounds were most effective when they were bound to Trp in a 1:1 ratio.

Claims

1. An anthracene diphenyl ether compound with AIE properties, characterized by the following structural formula: As shown below: 。 2. A method for preparing an anthracene diphenyl ether compound with AIE properties as described in claim 1, characterized in that... The synthesis route is as follows: 。 3. An application of an anthracene diphenyl ether compound with AIE properties as described in claim 1 as a fluorescent probe for recognizing small molecule substances, characterized in that... Application as a fluorescent probe for recognizing tryptophan.

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