Diphenyl ether compound with AEE characteristic, preparation method and application

Abstract

The invention discloses a diphenyl ether compound with AEE characteristics and a preparation method and application thereof. The diphenyl ether compounds with AEE characteristics are respectively 1, 4-bis (2, 2-bis (4-phenyl ether) vinyl) benzene or 4, 4 '-bis (2, 2-bis (4-phenyl ether) vinyl) biphenyl, both the two compounds have excellent AEE effect, the fluorescence emission intensity is improved compared with that of an existing fluorescence detection substance, the fluorescence detection substance has fluorescence enhancement response different from that of other amino acids on Trp, and the fluorescence detection substance can be applied to fluorescence detection of Trp. The fluorescent probe can specifically recognize tryptophan and is not influenced by other amino acids, the detection luminescence effect is obvious, the sensitivity is good, the detection limit is low, the response time is short, transient response can be carried out on Trp, the working time of Trp detection is greatly shortened, and the working efficiency is effectively improved. Experimental results show that the fluorescence emission intensities of the two compounds reach 5517 and 1781 respectively, the detection limits of specific recognition of tryptophan are 56.04 nM and 52.70 nM respectively, and the sensitivities (Ksv) are 8710 M <-1 > and 12610 M <-1 > respectively.

Description

Technical Field

[0001] The present invention belongs to the technical field of aggregation-induced enhanced luminescent materials, and in particular relates to a diphenyl ether compound with AEE characteristics, a preparation method and an application thereof. Background Art

[0002] Most traditional organic light-emitting materials emit strong fluorescence in a dispersed state, but once aggregated, ACQ (aggregation-induced quenching) occurs, limiting the application of light-emitting molecules in the field of materials. In 2001, Tang Benzhong's research group proposed the concept of aggregation-induced emission (AIE). Luminogens do not emit light in solution, but show strong fluorescence in an aggregated state. Subsequently, Park's research group discovered that some luminogens emit weakly in solution and show fluorescence enhancement (AEE) in an aggregated state. A large number of AIE / AEE macromolecules have been widely used in fluorescent chemical sensors, bioimaging, organic light-emitting diodes (OLEDs), cell tracking, clinical medicine and other fields due to their good solubility, easy processability, and high emission efficiency.

[0003] Tryptophan (Trp) is an essential amino acid that is decomposed through complex metabolic pathways. Its metabolites are biologically active and play a central role in physiology and pathophysiology. Tryptophan deficiency can lead to neurotransmitter depletion and mental disorders, while excessive intake of tryptophan may also lead to some neurological diseases. Therefore, it is of great significance to achieve simple, rapid and selective detection of tryptophan. At present, the main methods for determining tryptophan include spectrophotometry, fluorescence, high performance liquid chromatography, capillary electrophoresis, atomic absorption spectroscopy and electrochemical methods. However, the detection of tryptophan is often interfered by other amino acids. Therefore, most of the existing detection methods have the disadvantages of cumbersome equipment operation procedures, long detection cycle and low accuracy, which cannot meet the requirements of high standard identification of amino acids. Summary of the invention

[0004] The present invention aims to solve the above-mentioned technical problems existing in the prior art and provides a diphenyl ether compound with AEE characteristics, a preparation method and an application thereof.

[0005] The technical solution of the present invention is: a diphenyl ether compound with AEE characteristics, which is compound 1 or compound 2, wherein compound 1 is 1,4-bis(2,2-di(4-phenylene ether) vinyl)benzene, and compound 2 is 4,4'-bis(2,2-di(4-phenylene ether) vinyl)biphenyl, and the structural formulas of compound 1 and compound 2 are shown below:

[0006] Compound 1

[0007] Compound 2.

[0008] The preparation method of the diphenyl ether compound having AEE characteristics, the synthesis routes of compound 1 and compound 2 are respectively as follows:

[0009] Synthesis route of compound 1

[0010] Synthesis route of compound 2.

[0011] The preparation steps of compound 1 are as follows: Step 1. Add reactants 9,10-bis(dibromomethylene)-9,10-dihydroanthracene and 4-phenylether phenylboronic acid, catalyst Pd(PPh3)4 and K2CO3 providing an alkaline environment into a double-necked bottle containing 1,4-dioxane and deionized water; the dosage ratio of the 9,10-bis(dibromomethylene)-9,10-dihydroanthracene, 4-phenylether phenylboronic acid, Pd(PPh3)4, K2CO3, 1,4-dioxane and deionized water is 1.00 mmol:3.36 mmol:0.174 mmol:6.51 mmol:120 mL:24 mL; Step 2. Place the two-necked flask in an oil bath and fix it. Start magnetic stirring under N2 protection. Heat the oil bath to 90 °C. After fully reacting for 24 h, stop heating. After the reaction mixture cools to room temperature, use dichloromethane / water for extraction and washing. Step 3. Purify by silica gel column chromatography using a petroleum ether / dichloromethane mixed solvent with a volume ratio of 5:1 as an eluent to obtain a crude product; Step 4. Dichloromethane was added dropwise to the obtained crude product until it was just dissolved, and then ethanol was added for recrystallization to obtain compound 1.

[0012] The preparation steps of compound 2 are as follows: Step 1. Add reactants 4,4'-bis(2,2-dibromovinyl)biphenyl, 4-phenylether phenylboronic acid, catalyst Pd(PPh3)4 and K2CO3 providing an alkaline environment into a double-necked bottle containing 1,4-dioxane and deionized water, wherein the dosage ratio of 4,4'-bis(2,2-dibromovinyl)biphenyl, 4-phenylether phenylboronic acid, Pd(PPh3)4, K2CO3, 1,4-dioxane and 24 mL deionized water is 0.674 mmol:3.36 mmol:0.174 mmol:6.51 mmol:120 mL:24 mL; Step 2. Place the two-necked flask in an oil bath and fix it. Start magnetic stirring under N2 protection. Heat the oil bath to 90 °C. After fully reacting for 24 h, stop heating. After the reaction mixture cools to room temperature, use dichloromethane / water for extraction and washing. Step 3. Purify by silica gel column chromatography using a petroleum ether / dichloromethane mixed solvent with a volume ratio of 5:1 as an eluent to obtain a crude product; Step 4. Dichloromethane was added dropwise to the obtained crude product until it was just dissolved, and then ethanol was added for recrystallization to obtain Compound 2.

[0013] The above-mentioned diphenyl ether compounds with AEE characteristics are used as fluorescent probes for identifying small molecules, and specifically as fluorescent probes for identifying tryptophan.

[0014] The diphenyl ether compounds prepared by the present invention have excellent AEE effect, and the fluorescence emission intensity is improved compared with the existing fluorescence detection substances. They have a fluorescence enhancement response to Trp that is different from other amino acids, can specifically identify tryptophan and are not affected by other amino acids. The detection luminescence effect is obvious and has good sensitivity and a low detection limit. At the same time, the response time is short, and Trp can be responded to instantly, which greatly shortens the working time of Trp detection and effectively improves work efficiency. The experimental results show that the fluorescence emission intensities of the two compounds reach 5517 and 1781 respectively, and the detection limits of specific recognition of tryptophan are 56.04 nM and 52.70 nM respectively, and the sensitivity (Ksv) is 8710 M respectively. -1 , 12610 M -1 . BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is the compound prepared in Example 1 of the present invention 1 H NMR spectrum.

[0016] Figure 2 is the compound prepared in Example 2 of the present invention 1 H NMR spectrum.

[0017] Figure 3 It is a fluorescence spectrum diagram of the compound prepared in the embodiment of the present invention as a fluorescent probe interacting with different amino acids.

[0018] Figure 4 It is a three-dimensional diagram of the interaction between the compound prepared in the example of the present invention as a fluorescent probe and different types of amino acids at different concentration gradients.

[0019] Figure 5 The graphs are fluorescence spectra and ultraviolet absorption spectra of the compounds prepared in the examples of the present invention as fluorescent probes in titration experiments on Trp concentrations of different concentrations.

[0020] Figure 6 . is a Stern-Volmer curve and a linear relationship diagram of the compound prepared in the example of the present invention at different Trp concentrations.

[0021] Figure 7 This is a fluorescence spectrum diagram of the compound prepared in the embodiment of the present invention as a fluorescent probe and interference experiment with other amino acids and Trp.

[0022] Figure 8 It is a fluorescence spectrum diagram of the compound prepared in the embodiment of the present invention with different response times to Trp.

[0023] Fig. 9 It is a Job's curve diagram of the compound prepared in the example of the present invention. DETAILED DESCRIPTION

[0024] The present invention is described in detail below by specific examples, but the protection scope of the present invention is not limited. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can be obtained from commercial channels. Example 1

[0025] The preparation method of the diphenyl ether compound 1 having AEE characteristics of the present invention is carried out in the following steps: Step 1. Weigh two reactants 9,10-bis(dibromomethylene)-9,10-dihydroanthracene (0.52 g, 1.00 mmol) and 4-phenyletherphenylboronic acid (0.72 g, 3.36 mmol), then weigh the catalyst Pd(PPh3)4 (0.12 g, 0.174 mmol) and K2CO3 (0.9 g, 6.51 mmol) to provide an alkaline environment, and add the above four compounds into a two-necked bottle containing 120 mL 1,4-dioxane and 24 mL deionized water; Step 2. Place the two-necked flask in an oil bath, fix it with an iron stand, start magnetic stirring under N2 protection, heat the oil bath to 90°C, start the Suzuki coupling reaction, fully react for 24 h, then stop heating. After the reaction mixture cools to room temperature, use dichloromethane / water for extraction and washing; Step 3. Purify by silica gel column chromatography using a petroleum ether / dichloromethane mixed solvent (5 / 1, v / v) as an eluent to obtain a crude product; Step 4. Dichloromethane was added dropwise to the crude product until it was just dissolved, and then an appropriate amount of ethanol was added for recrystallization to obtain 0.4 g of product with a yield of 74.8%.

[0026] The compound 1 H NMR spectrum Figure 1 As shown, the structural formula is as follows:

[0027] Compound 1. Example 2

[0028] Step 1. Weigh two reactants, 4,4'-bis(2,2-dibromovinyl)biphenyl (0.3 g, 0.674 mmol), 4-phenyletherphenylboronic acid (0.72 g, 3.36 mmol), and then weigh the catalyst Pd(PPh3)4 (0.12 g, 0.174 mmol) and K2CO3 (0.9 g, 6.51 mmol) to provide an alkaline environment. Add the above four compounds into a two-necked bottle containing 120 mL of 1,4-dioxane and 24 mL of deionized water; Step 2. Place the two-necked flask in an oil bath, fix it with an iron stand, start magnetic stirring under N2 protection, heat the oil bath to 90°C, start the Suzuki coupling reaction, fully react for 24 h, then stop heating. After the reaction mixture cools to room temperature, use dichloromethane / water for extraction and washing; Step 3. Purify by silica gel column chromatography using a petroleum ether / dichloromethane mixed solvent (5 / 1, v / v) as an eluent to obtain a crude product; Step 4. Dichloromethane was added dropwise to the crude product until it was just dissolved, and then an appropriate amount of ethanol was added for recrystallization to obtain 0.4 g of product with a yield of 74.8%.

[0029] The 1H NMR spectrum of this compound is Figure 2 As shown, the structural formula is as follows:

[0030] Compound 2 Experiment 1: AEE performance test of two diphenyl ether compounds In order to prove that the two compounds have AEE effect, they were dissolved in tetrahydrofuran (THF) to prepare solutions. THF was used as a good solvent and water was used as a poor solvent. The two compounds were measured in their solutions (10 -4 mol / L). The excitation wavelength of the fluorescence spectrum was set to 300 nm, the slit width was set to 5:5, and the voltage was set to 550 V. By changing the volume fraction of water, (f w ) from 0% to 90% in THF / H2O mixture, and the intensity change of the solution (fw) from 0% to 90% was visually observed under UV light (365 nm).

[0031] The experimental results show that the fluorescence intensity of compound 1 in pure THF solution is 296.3. When the water content increases to 60%, the fluorescence intensity reaches a maximum of 5517, which is 18.62 times higher than that of pure THF solution. Correspondingly, the emission wavelength blue-shifts from 402.4 nm to 395.0 nm.

[0032] For compound 2, the fluorescence intensity in pure THF solution is 483.2. When the water content increases to 70%, the fluorescence intensity reaches a maximum of 1781, which is 3.68 times higher than that of pure THF solution. Correspondingly, the emission wavelength blue-shifts from 438.2 nm to 467.8 nm.

[0033] The above data show that the two compounds have typical AEE characteristics and are AEE compounds.

[0034] Experiment 2: Selectivity of two diphenyl ether compounds for amino acids In order to confirm the specific recognition of the two compounds on amino acids, the compounds prepared in Examples 1 and 2 of the present invention were used as fluorescent probes to interact with different amino acids. Specifically, 2 ml of compound 1 and 2 were added to 100 μM of 12 amino acids (Val, Thr, Ccp, Ala, Leu, Met, Pro, Ser, Cys, Lys, Glu, Trp), and the fluorescence spectra were as follows: Figure 3 (a) and (b). Figure 3 It can be seen that other amino acids did not respond significantly, and the fluorescence intensity changed slightly. Only when Trp was added, the fluorescence intensity changed dramatically, which can indicate the specific recognition of tryptophan by the two compounds.

[0035] Experiment 3: Fluorescence titration test of amino acids The compounds prepared in Examples 1 and 2 of the present invention were used as fluorescent probes to interact with different types of amino acids at different concentration gradients. The specific operation was to take 2 ml of each compound, add 0-100 μM of the above 12 amino acids in sequence for fluorescence titration test, and the three-dimensional graph was as follows: Figure 4 (a) and (b). Figure 4 It can be seen that with the increase of Trp concentration, the fluorescence intensity of the two compounds increased dramatically, and the fluorescence intensity of the compounds hardly changed when the concentration of other amino acids gradually increased. Among them, Ccp, Ala, and Val concentrated amino acids only showed a slight upward trend when they were added.

[0036] Experiment 4: Tryptophan concentration titration The compounds prepared in Examples 1 and 2 of the present invention were used as fluorescent probes to titrate different concentrations of Trp. The specific operation was to add 0-100 μM Trp to the two compounds in sequence to obtain their respective fluorescence emission spectra and ultraviolet absorption spectra, as shown in FIG. Figure 5 As shown in (a) and (b), the fluorescence emission spectra show that the emission wavelengths of the two compounds have undergone a significant blue shift and the fluorescence intensity has increased dramatically; the ultraviolet absorption spectra show that the absorbance of the two compounds has decreased.

[0037] Experiment 5: Sensitivity and detection limit for Trp The detection limit of a compound is calculated using the following formula: detection limit = 3σ / k; Where σ is the standard deviation of the blank compound measurement, and k is the slope value of the linear relationship between fluorescence intensity and Trp concentration. The linear relationship between the two compounds is shown in Figure 6 (a) and (b) show the correlation coefficient R of the two compounds. 2 As shown in Table 1, they are 0.98613 and 0.98462, respectively, indicating that they have a good linear relationship, and the k values ​​are 61.56 and 35.59, respectively. The corresponding detection limits calculated by σ and are 56.04 nM and 52.70 nM, respectively. Among them, the compound 2 has the lowest detection limit, which is conducive to the detection of Trp.

[0038] To explore compound detection Where I0 is the fluorescence intensity of the initial 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 in Figure 6 (a) and (b) show the correlation coefficients R of compounds 1 and 2. 2 As shown in Table 2, they are 0.98928 and 0.99270 respectively, indicating that they have a good linear relationship. The sensitivity (Ksv) is 8710M -1 , 12610 M -1 , both compounds have high sensitivity, so the response to tryptophan is better.

[0039] Table 1 Detection limits of two compounds

[0040] Table 2 Sensitivity of two compounds

[0041] Experiment 6: Interference Experiment In order to explore whether the presence of other amino acids would affect the detection of tryptophan by the compounds of the present invention, an interference experiment was conducted using the compounds prepared in Examples 1 and 2 of the present invention as fluorescent probes with other amino acids and Trp. Specifically, 10 μM of other amino acids and tryptophan were added alternately to measure their fluorescence intensity (twice each). The results are as follows Figure 7 (a) and (b). The experimental results show that the fluorescence intensity changes slightly when other amino acids are added, while the fluorescence intensity increases rapidly when tryptophan is added. When 10 μM other amino acids are repeatedly added, the effect on the fluorescence intensity is not significant. It is proved that the two compounds of the present invention are not interfered by other amino acids when detecting tryptophan, can specifically identify tryptophan, and are basically unaffected and have similar change trends when equal amounts of other amino acids are added.

[0042] Experiment 7: Response Time Test To investigate the fluorescence intensity of the two compounds at different response times to Trp, this experiment selected a Trp solution with a maximum titration concentration of 100 μM and directly added it to the compound. The fluorescence spectra are shown in Figure 2. Figure 8 (a) and (b) are shown. The results show that the fluorescence intensity of the solution rises rapidly when Trp is added to the two compounds, and then the fluorescence intensity changes slightly with the increase of response time. This shows that the two compounds can respond to Trp instantaneously, greatly shortening the working time of Trp detection and improving work efficiency.

[0043] Experiment 8: Job's Curve Analysis In order to explore the optimal binding ratio of the two compounds to Trp, Job's curve was used to illustrate. By controlling the total concentration of the compound and Trp to 100 μM, and then changing the ratio of the compound to Trp, Fig. 9 (a) and (b) can be observed through linear fitting that the fluorescence intensity of the combination of the two compounds [compounds] / [compounds+Trp] is the highest at about 0.5, indicating that the two compounds are best combined with Trp in a 1:1 ratio.

Claims

1. A diphenyl ether compound having AEE characteristics, characterized in that Compound 1 or Compound 2, wherein Compound 1 is 1,4-bis(2,2-di(4-phenylene oxide)vinyl)benzene, and Compound 2 is 4,4'-bis(2,2-di(4-phenylene oxide)vinyl)biphenyl, and the structural formulas of Compound 1 and Compound 2 are shown below: Compound 1 Compound 2.

2. The method for preparing diphenyl ether compounds having AEE characteristics according to claim 1, characterized in that The synthetic routes of compound 1 and compound 2 are as follows: Synthesis route of compound 1 Synthesis route of compound 2.

3. The method for preparing diphenyl ether compounds having AEE characteristics according to claim 2, characterized in that The preparation steps of compound 1 are as follows: Step 1. Add reactants 9,10-bis(dibromomethylene)-9,10-dihydroanthracene and 4-phenylether phenylboronic acid, catalyst Pd(PPh3)4 and K2CO3 providing an alkaline environment into a double-necked bottle containing 1,4-dioxane and deionized water; the dosage ratio of the 9,10-bis(dibromomethylene)-9,10-dihydroanthracene, 4-phenylether phenylboronic acid, Pd(PPh3)4, K2CO3, 1,4-dioxane and deionized water is 1.00 mmol:3.36 mmol:0.174 mmol:6.51 mmol:120 mL:24 mL; Step 2. Place the two-necked flask in an oil bath and fix it. Start magnetic stirring under N2 protection. Heat the oil bath to 90°C. After fully reacting for 24 h, stop heating. After the reaction mixture cools to room temperature, use dichloromethane / water for extraction and washing. Step 3. Purify by silica gel column chromatography using a petroleum ether / dichloromethane mixed solvent with a volume ratio of 5:1 as an eluent to obtain a crude product; Step 4. Dichloromethane was added dropwise to the obtained crude product until it was just dissolved, and then ethanol was added for recrystallization to obtain compound 1.

4. The method for preparing diphenyl ether compounds having AEE characteristics according to claim 2, characterized in that The preparation steps of compound 2 are as follows: Step 1. Add reactants 4,4'-bis(2,2-dibromovinyl)biphenyl and 4-phenylether phenylboronic acid, catalyst Pd(PPh3)4 and K2CO3 providing an alkaline environment into a double-necked bottle containing 1,4-dioxane and deionized water, wherein the dosage ratio of 4,4'-bis(2,2-dibromovinyl)biphenyl, 4-phenylether phenylboronic acid, Pd(PPh3)4, K2CO3, 1,4-dioxane and 24 mL deionized water is 0.674 mmol:3.36 mmol:0.174 mmol:6.51 mmol:120 mL:24 mL; Step 2. Place the two-necked flask in an oil bath and fix it. Start magnetic stirring under N2 protection. Heat the oil bath to 90°C. After fully reacting for 24 h, stop heating. After the reaction mixture cools to room temperature, use dichloromethane / water for extraction and washing. Step 3. Purify by silica gel column chromatography using a petroleum ether / dichloromethane mixed solvent with a volume ratio of 5:1 as an eluent to obtain a crude product; Step 4. Dichloromethane was added dropwise to the obtained crude product until it was just dissolved, and then ethanol was added for recrystallization to obtain Compound 2.

5. The use of the diphenyl ether compound with AEE characteristics as a fluorescent probe for identifying small molecules according to claim 1, characterized in that Application as a fluorescent probe for identifying tryptophan.

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