Preparation method of nano assembly with AIE effect
阅读说明：本技术 一种具有aie效应的纳米组装体的制备方法 (Preparation method of nano assembly with AIE effect ) 是由 关晓琳 丁媛媛 来守军 杨学琴 李�瑞 马金春 于 2020-12-18 设计创作，主要内容包括：本发明提供了一种具有AIE效应的纳米组装体的制备方法,将TPE-2Br、无水吡啶加入无水氯仿溶液中,氮气保护下,于65~70℃回流反应,冷却至室温,过滤,将溶液在甲基叔丁基醚中进行沉淀,离心,除去上清液,干燥,得到一维纳米组装体TPE-ON；将TPE-ON溶于甲醇中,加入甲基苯磺酸钠溶液,室温下搅拌反应,用二氯甲烷萃取,洗涤,干燥,过滤,滤液旋干后通过柱层析分离纯化,得到二维纳米组装体TPE-ONS。本发明通过改变分子中的抗衡离子,实现了具有AIE性质的一维纤维组装体向二维片状组装体的转换。TPE-ONS荧光强度为TPE-ON的2~2.5倍。在TPE-ON和TPE-ONS混合溶液中,荧光强度与TPE-ONS含量呈现一定相关性：Y=2113.71+5163.56x-2966.07X~2,通过此相关性可定量检测TPE-ON与TPE-ONS的相对含量并监测两者的交换过程。(The invention provides a preparation method of a nano assembly with AIE effect, which comprises the steps of adding TPE-2Br and anhydrous pyridine into an anhydrous chloroform solution, carrying out reflux reaction at 65-70 ℃ under the protection of nitrogen, cooling to room temperature, filtering, precipitating the solution in methyl tert-butyl ether, centrifuging, removing supernatant, and drying to obtain a one-dimensional nano assembly TPE-ON; and (2) dissolving TPE-ON in methanol, adding a sodium methyl benzenesulfonate solution, stirring for reaction at room temperature, extracting with dichloromethane, washing, drying, filtering, spin-drying the filtrate, and then separating and purifying by column chromatography to obtain the two-dimensional nano-assembly TPE-ONS. The invention realizes the two-dimensional orientation of the one-dimensional fiber assembly with AIE property by changing counter ions in moleculesAnd (5) converting the sheet assembly. The fluorescence intensity of the TPE-ONS is 2-2.5 times that of the TPE-ON. In the mixed solution of TPE-ON and TPE-ONS, the fluorescence intensity and the content of the TPE-ONS show a certain correlation: y =2113.71+5163.56X-2966.07X 2 By the correlation, the relative content of the TPE-ON and the TPE-ONS can be quantitatively detected and the exchange process of the TPE-ON and the TPE-ONS can be monitored.)
1. A method for preparing a nano-assembly having AIE effect, comprising the steps of:
(1) preparation of TPE-2 OH: dissolving 4-hydroxybenzophenone and zinc powder in anhydrous tetrahydrofuran, and adding TiCl in an ice-water bath under the protection of nitrogen4Stirring for 25-35 min, and performing reflux reaction at 65-75 ℃ for 20-24 h; after the reaction is finished, cooling to room temperature, and adding K2CO3Quenching the reaction in solution with CH2Cl2Extracting, removing an organic layer by rotary evaporation, purifying a crude product by a silica gel column, and drying in vacuum to obtain a product 1, 4-dihydroxy tetraphenylethylene TPE-2 OH;
(2) preparation of TPE-2 Br: 1, 8-dibromooctane and anhydrous K2CO3And TPE-2OH are dissolved in acetonitrile, and are stirred and refluxed for 20-24 hours at 80-85 ℃ under the protection of nitrogen; inverse directionAfter the reaction is finished, cooling to room temperature and using CH2Cl2Dissolving and filtering, and separating and purifying the filtrate by column chromatography after spin-drying to obtain 1, 4-dibromooctyltetraphenylether TPE-2 Br;
(3) and (3) preparing TPE-ON: adding TPE-2Br and anhydrous pyridine into an anhydrous chloroform solution, refluxing for 20-24 h at 65-70 ℃ under the protection of nitrogen, cooling to room temperature, filtering, precipitating the obtained solution in methyl tert-butyl ether, centrifuging, removing supernatant, and drying to obtain the one-dimensional nano assembly TPE-ON.
2. The method of claim 1, wherein the nano-assembly having AIE effect is prepared by: and (2) dissolving TPE-ON in methanol, adding a sodium methyl benzenesulfonate solution, stirring and reacting at room temperature for 10-12 hours, extracting a reaction system by using dichloromethane, washing with saturated saline solution, combining organic phases, drying and filtering by using anhydrous magnesium sulfate, spin-drying filtrate, and separating and purifying by using a column chromatography method to obtain the two-dimensional nano-assembly TPE-ONS.
3. A method for preparing nano-assemblies with AIE effect according to claim 1 or 2, wherein: in the step (1), the molar ratio of the 4-hydroxybenzophenone to the zinc powder is 1.5: 1-2.5: 1.
4. A method for preparing nano-assemblies with AIE effect according to claim 1 or 2, wherein: in the step (1), 4-hydroxybenzophenone and TiCl4The molar ratio of (a) to (b) is 1:20 to 1: 30.
5. A method for preparing nano-assemblies with AIE effect according to claim 1 or 2, wherein: in the step (2), the molar ratio of the TPE-2OH to the 1, 8-dibromooctane is 1: 1-1: 3.
6. A method for preparing nano-assemblies with AIE effect according to claim 1 or 2, wherein: in the step (2), TPE-2OH and anhydrous K2CO3In a molar ratio of 1:1~1.5:1。
7. A method for preparing nano-assemblies with AIE effect according to claim 1 or 2, wherein: in the step (3), the molar ratio of TPE-2Br to anhydrous pyridine is 1: 1-1: 3.
8. A method for preparing nano-assemblies with AIE effect according to claim 1 or 2, wherein: the molar ratio of TPE-ON to methylbenzenesulfonic acid is 1: 1-1: 2.
Technical Field
The invention relates to a preparation method of a nano assembly, in particular to a preparation method of a nano assembly with AIE effect, belonging to the technical field of nano materials.
Background
The fluorescent molecular imaging detection technology is used for specifically marking biological molecules through a fluorescent probe, further monitoring a fluorescent signal in real time to realize visual automatic imaging, and is one of the most important research means in the current biomedical technical research. Aggregation-induced emission (AIE) materials, as an emerging class of smart materials, have unique optical properties and good biocompatibility. At present, the method is widely applied to a plurality of fields, such as chemical sensing, intelligent nano materials, biological imaging and the like. Among them, Tetraphenylethylene (TPE) has been widely studied and applied since its structure is simple, synthesis is simple and convenient, and modification is easy. For example, Tang et al prepared TPE-TPP molecules (Leung C W, Hong Y, Chen S, et al, A photostable AIE luminescence gene for specific mitogenic imaging and tracking [ J ]. J. Am. chem. Soc., 2013, 135 (1): 62-65.) by linking two groups of positively charged triphenylphosphine using TPE as the fluorophore. The positively charged triphenylphosphine group has strong electrostatic interaction with negatively charged mitochondria, so that the mitochondria can be targeted. Because of their large membrane potential, they also designed TPE-PyN3 compounds (Situ B, Chen S, ZHao E, et al, Real-Time Imaging of Cell bhaviors in Living Organisms by a Mitochondria-Targeting AIE Fluorogen [ J ]. Adv. Funct. mater., 2016, 26(39): 7132-7138.), which also have strong mitochondrial Targeting ability. Due to good targeting ability, light stability and low biological toxicity, the in vivo long-time tracing and imaging can be effectively realized.
Common one-dimensional organic assemblies include nanowires, nanorods, nanotubes, and the like; two-dimensional organic assembly nano-film and nano-coating, etc. They are formed by weak intermolecular and intramolecular interactions and are often used in the fields of optical, electrical, magnetic, and biomedical applications. However, the assemblies formed in amphiphilic molecules in most of the related reports are mostly one-dimensional or zero-dimensional structures, such as fibers and spherical micelles. The two-dimensional organic assembly has an ordered structure with special appearance and properties, and has huge application potential in the field of photoelectron. According to related research reports, hydrophobic organic anions are used as counter ions of amphiphilic molecules, so that electrostatic repulsion between hydrophilic head groups can be weakened, and the assembly structure of the amphiphilic molecules is induced to be converted from one dimension to two dimensions. In 2005, The Zhang academy team studied a pyrrolopyrrole dione-containing amphipathic molecule 5,5-B2NBr8 which formed two-dimensional lamellar aggregates 5,5-B2NTs8 (Song B, Wang Z Q, Chen S L, Xi Zhang, Fu Y, et al, The Introduction of pi-Stacking Moielies for purifying colloidal structure: Formation and Dynamics of Disklike microorganisms [ J ] Angel. chem. int. Ed., 2005, 44: 4731-, verwilst P, Liu K, Zhang X, et al, Controlling the sectional-Assembly of functional Bolaampiphiles from 0D/1D to exclusive 2D Planar Structures [ J ] chem. Sci., 2013, 4, 4486-4493 ]. Research results show that when the counter ion is bromide ion, the amphiphilic molecules form one-dimensional assemblies when self-assembling in water, and when the counter ion is converted into p-methyl benzene sulfonate, the assemblies are two-dimensional sheet structures. This phenomenon suggests that the structure of the counter ion in the molecule will largely determine the morphology of the assembly. However, the aggregation degree of molecules corresponding to different assembly morphologies is different, for example, the aggregation degree of molecules in a two-dimensional assembly should be greater than that of a one-dimensional assembly, so that if the AIE molecules are introduced into a one-dimensional/two-dimensional assembly system, the fluorescence property will change obviously with the change of the assembly morphology, thereby realizing the identification of the morphology of the assembly and the quantitative detection and analysis of the relative content of the one-dimensional/two-dimensional mixed components. However, the research on the aspect of organic assemblies based on AIE characteristics is relatively less, and the conversion of preparing the assembly morphology with fluorescent response through ion regulation is not reported in relevant documents.
Disclosure of Invention
The invention aims to provide a preparation method of a nano assembly with AIE effect.
Preparation of nano assembly with AIE effect
The preparation method of the nano assembly with the AIE effect comprises the following steps:
(1) preparation of TPE-2 OH: dissolving 4-hydroxybenzophenone and zinc powder in anhydrous tetrahydrofuran, and adding TiCl in an ice-water bath under the protection of nitrogen4Stirring for 25-35 min, and performing reflux reaction at 65-75 ℃ for 20-24 h; after the reaction is finished, cooling to room temperature, and adding K2CO3Quenching the reaction in solution with CH2Cl2Extracting, removing an organic layer by rotary evaporation, purifying the crude product by a silica gel column, and drying in vacuum to obtain the product 1, 4-dihydroxy tetraphenylethylene TPE-2 OH. Wherein the molar ratio of the 4-hydroxybenzophenone to the zinc powder is 1.5: 1-2.5: 1; 4-hydroxybenzophenones with TiCl4The molar ratio of (a) to (b) is 1:20 to 1: 30.
(2) Preparation of TPE-2 Br: 1, 8-dibromooctane and anhydrous K2CO3And TPE-2OH are dissolved in acetonitrile, and are stirred and refluxed for 20-24 hours at 80-85 ℃ under the protection of nitrogen; after the reaction is finished, the reaction mixture is cooled to room temperature and CH is used2Cl2Dissolving and filtering, and separating and purifying the filtrate by column chromatography after spin-drying to obtain 1, 4-dibromooctyltetraphenylethylene ether TPE-2 Br. Wherein the molar ratio of the TPE-2OH to the 1, 8-dibromooctane is 1: 1-1: 3; TPE-2OH and Anhydrous K2CO3The molar ratio of (a) to (b) is 1:1 to 1.5: 1.
(3) And (3) preparing TPE-ON: adding TPE-2Br and anhydrous pyridine into an anhydrous chloroform solution, refluxing for 20-24 h at 65-70 ℃ under the protection of nitrogen, cooling to room temperature, filtering, precipitating the obtained solution in methyl tert-butyl ether, centrifuging, removing supernatant, and drying to obtain the one-dimensional nano assembly TPE-ON. Wherein the mol ratio of the TPE-2Br to the anhydrous pyridine is 1: 1-1: 3.
The preparation of TPE-ONS of the invention: and (2) dissolving TPE-ON in methanol, adding a sodium methyl benzenesulfonate solution, stirring and reacting at room temperature for 10-12 hours, extracting a reaction system by using dichloromethane, washing with saturated saline solution, combining organic phases, drying and filtering by using anhydrous magnesium sulfate, spin-drying filtrate, and separating and purifying by using a column chromatography method to obtain the two-dimensional nano-assembly TPE-ONS. Wherein the molar ratio of the TPE-ON to the methylbenzenesulfonic acid is 1: 1-1: 2.
The TPE-ON nuclear magnetic hydrogen spectrum and nuclear magnetic carbon spectrum are shown in figures 1 and 2, and the TPE-ONS nuclear magnetic hydrogen spectrum is shown in figure 3.
The synthetic routes of TPE-ON and TPE-ONS are as follows:
。
II, structural characterization of TPE-ON and TPE-ONS
1. EDS analysis of TPE-ON and TPE-ONS
The structure of the molecule was determined by nuclear magnetic, mass spectrometry. To further determine the elemental composition of the material, we performed EDS testing. The molecular formulas of TPE-ON and TPE-ONS are respectively C52H60O2Br2And C66H74N2O2S2. As can be seen from FIG. 4, TPE-ON contains C, O, N and Br elements, and TPE-ONS contains C, O, N and S elements. The molecular formula is consistent with the elements contained in the molecular formula, and the test result further proves that the TPE-ON and the TPE-ONS are successfully prepared.
2. Self-assembly morphology of TPE-ON and TPE-ONS
Firstly, TPE-ON is dissolved in water to prepare the TPE-ON with the concentration of 1 multiplied by 10-3And (3) performing ultrasonic treatment ON 5.0 mL of the solution in mol/L for 5min, dripping a small amount of TPE-ON solution ON a tin sheet, standing for about 20 min to completely volatilize the solvent in the sample, and observing the morphology of the TPE-ON sample by a Scanning Electron Microscope (SEM). Dissolving TPE-ONS in water to obtain a solution with a concentration of 1 × 10-3 molAnd (2) taking 5.0 mL of the solution for ultrasonic treatment, dropping a small amount of TPE-ONS solution onto a copper mesh after the ultrasonic treatment is carried out for 5min, and observing the assembly morphology of the sample through a Transmission Electron Microscope (TEM) after the solvent is completely volatilized. Since the two-dimensional sheet assembly is thin, it is measured by a transmission electron microscope.
The scanning electron microscope image of TPE-ON and the transmission electron microscope image of TPE-ONS are shown in FIG. 5, the TPE-ON assembly is one-dimensional fiber-shaped, and the TPE-ONS assembly is two-dimensional sheet-shaped. The experimental result shows that when bromide ions are converted into p-toluenesulfonate, the morphology is subjected to dimensional change, and is converted from one-dimensional fibrous shape into two-dimensional flaky shape, which is caused by the p-toluenesulfonate. The p-toluenesulfonate is an amphiphilic organic anion, which has a hydrophilic sulfonate part and a hydrophobic benzene ring part, so that when the p-toluenesulfonate is used as a counter ion to participate in the self-assembly of molecules, the hydrophilic part can be combined with a head group, and the hydrophobic part can be inserted into the interior of an assembly, thereby weakening the electrostatic repulsion between the head group and the head group between two molecules, and leading TPE-ONS amphiphilic molecules to be stacked in two directions in a mutually parallel mode so as to be assembled into a two-dimensional sheet-shaped assembly. When bromide is used as a counter ion, the binding capacity of the bromide to a cationic head group is weak, so that a large electrostatic repulsion effect exists between the head group and the head group, and TPE-ON amphiphilic molecules are directionally arranged to form a one-dimensional fibrous assembly mainly by virtue of an intermolecular pi-pi accumulation effect. In conclusion, the AIE amphiphilic fluorescent molecule one-dimensional fiber assembly and the two-dimensional sheet assembly are prepared, and effective conversion from the one-dimensional fiber assembly to the two-dimensional sheet assembly is realized by changing counter ions.
II, characteristics of TPE-ON and TPE-ONS
1. Critical micelle concentration of TPE-ON and TPE-ONS
The critical micelle concentration is a very important parameter in studying the self-assembly of amphiphilic molecules, and reflects the ability and possibility of amphiphilic molecules to self-assemble to form aggregates. A lower critical micelle concentration indicates that the amphiphilic molecule is more likely to form aggregates in solution, whereas the molecule is more likely to be in the form of a monomerThe formula (II) is dissolved in the solution without aggregation. Still other molecules are unable to form aggregates due to insufficient hydrophobic capacity. We measured the critical micelle concentration of the synthesized TPE-ON and TPE-ONS by the conductance method. TPE-ON was formulated into a range of concentrations of solutions, the conductivity of these solutions was measured, and then plotted as conductivity versus concentration. As shown in FIG. 6 (a), the gradient of the conductivity of the TPE-ON solution to the concentration changes with the increase of the concentration, and the concentration at the point of the curve where the gradient changes is the critical micelle concentration of the solution, i.e. the critical micelle concentration of the TPE-ON at room temperature is 8.5X 10-4 mol/L. In the same way as in FIG. 6 (b), we measured the critical micelle concentration of TPE-ONS molecules to be 7.6X 10-4 mol/L. Through the experiments, the lowest concentration of the TPE-ON and the TPE-ONS when forming an assembly is obtained, and meanwhile, the TPE-ONS has smaller critical micelle concentration than the TPE-ON, which shows that TPE-ONS molecules can form aggregates in water more easily.
2. AIE characteristics of TPE-ON and TPE-ONS
TPEs are typical AIE molecules with a structure where the central olefin is surrounded by four peripheral aromatic benzene rings, and TPEs in dilute solution emit little light. This is because the exciton energy is dissipated in a non-radiative manner as the aromatic ring rotates about the single bond axis relative to the central olefin. After aggregate formation, TPEs induce emission through the synergistic effect of intramolecular spin confinement and highly distorted molecular conformations that block intermolecular pi-pi stacking interactions. Therefore, TPE-ON and TPE-ONS containing TPE luminophores have typical AIE characteristics, which are verified below from TPE-ON and TPE-ONS in poor solvents and different concentrations, respectively.
(1) AIE Effect in poor solvents
The tetraphenylethylene-containing compounds TPE-ON and TPE-ONS are easily dissolved in Tetrahydrofuran (THF) and difficultly dissolved in dichloromethane (CH)2Cl2). THF and CH are prepared respectively2Cl2(V: V) = 9: 1, 8: 2, 6: 4, 5: 5, 4: 6, 3: 7, 2: 8, 1: 9 mixed solution, and the final concentration of the compounds TPE-ON and TPE-ONS is maintained at 100. mu.M. And (3) immediately testing the fluorescence property of the prepared mixed solution after 5min of ultrasonic treatment.As shown in FIG. 7, the fluorescence intensity gradually increases when the poor solvent content is from 0% to 50% by volume, and becomes stable when the fluorescence intensity is increased more than 50% by volume to a certain degree of aggregation. The higher the content of the poor solvent, the more remarkable the degree of aggregation in the molecule, and the stronger the fluorescence intensity. Thus, it can be seen that both compounds TPE-ON and TPE-ONS exhibit aggregation-induced luminescence enhancement, with unique AIE characteristics.
(2) AIE Effect in different concentrations
For the AIE properties of TPE-ON and TPE-ONS, we have demonstrated two aspects. ON the other hand, the effect of the change of fluorescence intensity with the change of concentration was examined, and as shown in FIG. 8 (a, b), the fluorescence of TPE-ON was weak in the range of 40-80. mu.M concentration in the tetrahydrofuran solution, and strong fluorescence was exhibited when the concentration was gradually increased from 80. mu.M. Aggregation occurs within the TPE-ON molecule with increasing concentration, and a significant increase in fluorescence indicates that the compound has typical AIE properties. As shown in FIG. 8 (c, d), the fluorescence of TPE-ONS is very weak at a concentration of 80 uM or less, and very strong fluorescence is exhibited when the concentration is gradually increased from 200. mu.M. The TPE-ONS molecules aggregate with increasing concentration, and the fluorescence increases significantly indicating that the compound has typical AIE properties.
3. Optical Properties of TPE-ON and TPE-ONS
To further investigate the optical properties of TPE-ON and TPE-ONS, we tested the fluorescence properties of TPE-ON and TPE-ONS, FIG. 9 is a concentration of 1X 10-3 TPE-ON and TPE-ONS of M in DMSO and H2O mixed solution (DMSO: H)2O = 1: 9) fluorescence excitation spectrum and fluorescence emission spectrum. The excitation wavelength of the TPE-ON is 365 nm, and the emission wavelength is 480 nm. The excitation wavelength of the TPE-ONS is 355 nm and the emission wavelength is 480 nm under the same condition.
Meanwhile, the contrast concentration is 1X 10-3 The fluorescence intensity of the TPE-ON and TPE-ONS solutions of M was found to be 671 and 1554, respectively, and the fluorescence intensity of the TPE-ONS was 2.3 times that of the TE-ON (see FIG. 10). This is mainly due to the TPE-ON and TPE-The benzene rings in the ONS molecule rotate freely, releasing a large amount of energy in the form of nonradiative transitions. When aggregation occurs, the rotation of benzene rings in the molecule is hindered, and when the molecule is excited, energy can be released only in the form of radiative transition, so that stronger fluorescence can be obtained in an aggregation state. The TPE-ON forms a one-dimensional fibrous aggregate in the assembling process, and the TPE-ONS forms a two-dimensional flaky aggregate in the assembling process, and compared with the fibrous aggregate, the aggregation degree of the flaky aggregate is larger, so that the fluorescence intensity of the two-dimensional aggregate is stronger.
We tested TPE-ON and TPE-ONS at a series of different concentrations separately for their fluorescence intensities (5X 10)-5 M、1×10-5 M、1×10-4 M、1×10-3M). As shown in FIG. 11, the excitation wavelengths of TPE-ON and TPE-ONS solutions at different concentrations are red-shifted with increasing concentrations, and the fluorescence intensity is gradually increased.
FIG. 12 is a comparison of the fluorescence emission spectra of TPE-ON and TPE-ONS at different concentrations and histograms showing that when the concentrations are 1X 10-5 And in the case of M, the maximum fluorescence value of the TPE-ON is 128.9, the fluorescence value of the TPE-ONS is 61.9, and the fluorescence intensity of the TPE-ON is about 2 times that of the TPE-ONS, because the concentration of the solution is small, molecules move freely in the solution, and no aggregation phenomenon occurs, the fluorescence is weak. When the concentration reaches 1X 10-4 M, the fluorescence values of TPE-ON and TPE-ONS are 1087 and 1066 respectively, and the fluorescence values of the TPE-ON and the TPE-ONS are very close to each other. Further increasing the concentration of the solution, we found that when the concentration was 1X 10-3 And M, the maximum fluorescence value of the TPE-ON is 2427, the fluorescence value of the TPE-ONS is 5512, and the fluorescence intensity of the TPE-ONS is about 2 times that of the TPE-ON, which shows that the fluorescence intensity of the sheet-shaped TPE-ONS is about 2 times that of the TPE-ON after the self-assembly happens only when the concentrations of the TPE-ON and the TPE-ONS exceed the critical value. To judge when the concentration of the two exceeds 1X 10-3 After M, whether the self-assembled morphology was stable, we increased the concentration to 5X 10-3 And M. As can be seen from FIG. 12, the fluorescence intensity of TPE-ONS is still about 2 times that of TPE-ON with the same proportional increase in fluorescence value with increasing concentration, indicating that the molecules are in solutionThe assembly morphology is stabilized, so the ratio of fluorescence intensity of the two does not change, but the number of molecules aggregated by increasing the concentration increases, so the fluorescence values of the two increase to the same extent.
4. Correlation of TPE-ON and TPE-ONS
FIG. 13 shows fluorescence emission spectra (a) and correlation plots (b) of TPE-ON and TPE-ONS mixed solutions with different volume fractions. The concentrations of TPE-ON and TPE-ONS solutions are 1X 10-3 Under the condition of M, fluorescence changes of TPE-ON and TPE-ONS mixed solutions containing different volume fractions (0%, 20%, 40%, 60%, 80%, 100%) of TPE-ONS are measured, and it can be seen from FIG. 13 that the fluorescence intensity is gradually enhanced along with the increase of the proportion of TPE-ONS, and changes in a certain relation are presented, and the change trend of the fluorescence intensity is simulated by Oringin software to obtain good correlation. The correlation formula is Y =2113.71+5163.56X-2966.07X2Wherein Y is the fluorescence intensity of the mixed solution of TPE-ON and TPE-ONS; and X is the volume content of the TPE-ONS in the mixed solution. According to the formula, the fluorescence intensity and the contents of the TPE-ON and TPE-ONS mixed solutions have a certain proportional relation, the complex process that the one-dimensional fibrous assembly TPE-ON is converted into the two-dimensional sheet assembly TPE-ONS can be detected by utilizing the correlation, whether the one-dimensional fibrous assembly is completely converted in the reaction process can be obtained through the fluorescence intensity measurement at a certain time point, and a feasible scheme is provided for the preparation and research of the materials.
In conclusion, the amphiphilic nano-assembly with the AIE effect is prepared based ON the tetraphenylethylene group, the conversion from a one-dimensional fiber assembly (TPE-ON) with the AIE effect to a two-dimensional sheet assembly (TPE-ONS) is realized by changing counter ions in molecules, and after the TPE-ON and the TPE-ONS are formed, the fluorescence intensity of the TPE-ONS is 2-2.5 times that of the TPE-ON; in the mixed solution of TPE-ON and TPE-ONS, the fluorescence intensity and the content of the TPE-ONS show a certain correlation: y =2113.71+5163.56X-2966.07X2And the relative content of the TPE-ON and the TPE-ONS can be quantitatively detected through the correlation, and the exchange process of the TPE-ON and the TPE-ONS can be monitored.
Drawings
FIG. 1 is a nuclear magnetic hydrogen spectrum of TPE-ON;
FIG. 2 is a nuclear magnetic carbon spectrum of TPE-ON;
FIG. 3 is a nuclear magnetic hydrogen spectrum of TPE-ONS;
FIG. 4 is EDS spectra of TPE-ON and TPE-ONS;
FIG. 5 is an SEM image of TPE-ON and a TEM image of TPE-ONS;
FIG. 6 shows the conductivity of TPE-ON versus TPE-ONS at different concentrations;
FIG. 7 shows TPE-ON and TPE-ONS at different volume fractions CH2Cl2Fluorescence spectra in solution (a, c) and corresponding trends in fluorescence intensity (b, d);
FIG. 8 shows the fluorescence spectra (a, c) and the corresponding trend of fluorescence intensity (b, d) for different concentrations of TPE-ON and TPE-ONS solutions;
FIG. 9 shows TPE-ON and TPE-ONS in DMSO/H2Fluorescence excitation spectrum and fluorescence emission spectrum in the O mixed solution;
FIG. 10 shows the concentration of 1X 10-3 A comparison graph of fluorescence spectra of TPE-ON and TPE-ONS solutions of M;
FIG. 11 is a graph of the fluorescence spectra of TPE-ON and TPE-ONS at different concentrations;
FIG. 12 is a comparison of the fluorescence emission spectra and histograms of TPE-ON and TPE-ONS at different concentrations;
FIG. 13 shows fluorescence emission spectra (a) and correlation plots (b) of TPE-ON and TPE-ONS mixed solutions with different volume fractions.
Detailed Description
The preparation of the nano-assemblies with AIE effect according to the present invention is further illustrated by the following specific examples.
(1) Synthesis of 1, 4-dihydroxytetraphenylethylene (TPE-2 OH)
Dissolving 4-hydroxybenzophenone (1.98 g, 1 mmol) in 100 mL of anhydrous tetrahydrofuran, adding zinc powder (3.45 g, 0.5 mmol), vacuumizing and introducing nitrogen for three times to allow the whole reaction process to be carried out under a nitrogen atmosphere, and then slowly adding TiCl dropwise under ice-water bath conditions4(2.8 mL), stirringAfter 30 min, the whole apparatus under vacuum was transferred to an oil bath and reacted at reflux temperature for 24 hours, after which the reaction was cooled to room temperature and K was added with vigorous stirring2CO3The reaction was quenched with aqueous solution (20 mL, 10%). By CH2Cl2Extracting to separate organic phase, combining organic phases, and adding anhydrous Na2SO4And (5) drying. The organic layer was evaporated by rotation and the crude product was purified through a silica gel column eluting with ethyl acetate and petroleum ether at a volume ratio of 1: 8. A white solid was obtained which was then dried under vacuum. The yield was 74.5%.
1H NMR (600 MHz, Chloroform-d) δ 7.13 – 7.09 (m, 6H), 7.03 (dd, J = 7.9, 1.8 Hz, 4H), 6.91 – 6.88 (m, 4H), 6.57 (d, J = 8.6 Hz, 4H).
13C NMR (151 MHz, Chloroform-d) δ 153.87, 143.99, 139.63, 136.59, 132.68, 127.63, 127.53, 126.19, 114.59.
ESI-MS: m/z calcd for C26H20O2 [M]+, 364.1457; found 364.1452.
(2) Synthesis of 1, 4-dibromooctylene tetraphenylether (TPE-2 Br)
1, 8-dibromooctane (1.087 g, 4 mmol) and anhydrous K are taken2CO3(0.138 g, 1.5 mmol) was added to 300 mL of acetonitrile solution. The system was evacuated and nitrogen purged for three repeated cycles with heating and stirring, a solution of TPE-2OH (0.364 g, 2 mmol) in acetonitrile (40 mL) was slowly added at reflux with a syringe and the mixture was stirred at 82 ℃ for 24 h. After cooling to room temperature, use CH2Cl2Dissolving and filtering to remove K in the solution2CO3The solid, filter cake was washed 3 times with acetone and MgSO4Drying, mixing filtrates, spin-drying, and separating and purifying by column chromatography. Pure TPE-2Br was obtained in 49% yield.
1H NMR (600 MHz, Chloroform-d) δ 7.09 – 7.05 (m, 6H), 7.05 – 7.02 (m, 4H), 6.88 (d, J = 8.8 Hz, 4H), 6.60 (d, J = 8.8 Hz, 4H), 3.89 – 3.86 (m, 4H), 3.42 – 3.40 (m, 4H), 1.85 (dtd, J = 14.6, 7.0, 3.4 Hz, 8H), 1.34 (dtd, J = 10.2, 5.6, 5.1, 2.4 Hz, 16H).
13C NMR (151 MHz, Chloroform-d) δ 157.46 , 132.47 , 127.59 , 127.48 ,126.08 , 113.58 , 113.49 , 67.69 , 33.94 , 32.76 , 29.26 , 29.23 , 28.64 , 28.06 , 25.94 .
ESI-MS: m/z calcd for C42H52O2Br2 [M]+, 746.2159; found 746.2152.
(3) Synthesis of TPE-ON
Anhydrous pyridine (5 mL, 4 mmol), TPE-ON (0.12 g, 2 mmol) was added to 10 mL of anhydrous chloroform solution and the reaction was refluxed at 65 ℃ for 24 hours under nitrogen atmosphere. After that, the mixture was cooled to room temperature, followed by filtration to remove a white solid, the resulting solution was precipitated in methyl t-butyl ether, centrifuged, and the supernatant was removed to give a pale yellow oily product, which was dried in a vacuum oven at room temperature for 24 hours in 43% yield.
1H NMR (600 MHz, DMSO-d 6) δ 9.06 (d, J = 6.7 Hz, 4H), 8.57 (t, J = 7.8 Hz, 2H), 8.13 (t, J = 7.0 Hz, 4H), 7.13 – 7.02 (m, 12H), 6.90 (t, J = 6.5 Hz, 4H), 6.82 (d, J = 8.8 Hz, 2H), 6.73 (d, J = 8.6 Hz, 2H), 6.67 (dd, J = 16.9, 8.7 Hz, 4H), 6.61 (d, J = 8.8 Hz, 2H), 6.48 (ddd, J = 22.9, 8.8, 2.5 Hz, 4H), 4.57 (t, J = 6.2 Hz, 4H), 3.85 – 3.80 (m, 4H), 1.97 (dt, J = 11.9, 6.8 Hz, 4H), 1.62 (q, J = 8.5, 7.3 Hz, 4H), 1.32 – 1.23 (m, 16H).
13C NMR (151 MHz, Chloroform-d) δ 157.46 , 144.33 , 139.59 , 136.18 , 132.47 , 131.37 (d, J = 4.0 Hz), 127.54 (d, J = 17.0 Hz), 126.08 , 113.49 , 77.42 – 75.71 (m), 67.69 , 33.94 , 32.76 , 29.45 – 27.10 (m), 25.94 .
ESI-MS: m/z calcd for C52H60O2Br2Cl[M+Cl]+,937.2704; found 937.2709.
EXAMPLE 2 Synthesis of TPE-ONS
Dissolving TPE-ON (0.18 g and 0.1 mol) in 3mL of methanol solution, dissolving sodium p-toluenesulfonate (0.15 g and 0.2 mol) in 3mL of deionized water, mixing the two solutions, stirring at room temperature for 12 hours, pouring the reaction solution into water after the reaction is completed, extracting the reaction system with dichloromethane, washing with saturated saline solution for three times, combining organic phases, drying and filtering with anhydrous magnesium sulfate, spin-drying the filtrate, and separating and purifying the filtrate by column chromatography to obtain a light yellow oily solid with the yield of 62%.
1H NMR (600 MHz, DMSO-d 6) δ 9.06 (d, J = 2.1 Hz, 4H), 8.58 – 8.55 (m, 2H), 8.13 – 8.08 (m, 4H), 7.45 – 7.43 (m, 8H), 7.11 – 7.02 (m, 4H), 6.94 – 6.91 (m, 8H), 6.83 – 6.80 (m, 2H), 6.66 – 6.62 (m, 4H), 3.81 (dt, J = 12.4, 6.4 Hz, 4H), 2.46 (d, J = 1.9 Hz, 6H), 1.98 – 1.82 (m, 4H), 1.63 – 1.56 (m, 8H), 1.28 – 1.17 (m, 16H).
ESI-MS: m/z calcd for C66H74N2O2S2 [M+Na]+,1109.4784; found 1109.4786.