Bonded imine-based three-component spherical covalent organic framework-based stationary phase, preparation method and application thereof

Abstract

The application discloses a bonded imine three-component spherical COF-based stationary phase and a preparation method and application thereof, and the preparation method comprises the following steps: S1, synthesizing an imine three-component spherical COF containing an alkyne group bonding arm; S2, bonding monosubstituted 6-azido-6-deoxy-3,5-dimethoxy anilino carbamoylated beta-cyclodextrin to the three-component spherical COF prepared in the step S1 by means of a click chemistry method to prepare a bonded imine three-component spherical COF-based chiral stationary phase. The bonded imine three-component spherical COF-based stationary phase has the advantages of simple and convenient synthesis process, good stability of the prepared bonded imine three-component spherical COF-based stationary phase and good application prospect in HPLC separation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of chromatographic separation, and particularly relates to a bonded imine three-component spherical COF-based stationary phase, a preparation method thereof and application thereof. BACKGROUND

[0002] Traditional silica-based stationary phases are generally divided into coated and bonded types according to their solvent resistance. Coated chiral stationary phases, in which the selector is physically compounded, have good separation performance, but are sometimes limited by solvent resistance, and therefore, the selectors need to be covalently connected to the matrix material to obtain bonded stationary phases, so as to fill the gaps in some situations where coated stationary phases are difficult to apply, and complement the functions of coated stationary phases.

[0003] Covalent organic frameworks (COFs) are a new type of crystalline porous material that has developed rapidly in the past decade. This type of material is favored by scientific researchers due to its good crystallinity, low density, strong stability, high specific surface area, adjustable framework size, and easy modification of pores, and has been proven to have broad application prospects in the fields of heterogeneous catalysis, gas storage, chemical sensing, and optoelectronic materials. In recent years, with the development of high-stability COF construction and COF morphology control technology, the practical application of COF materials has also become increasingly mature. Among them, the application of COF materials in high-performance liquid chromatography separation has attracted widespread attention.

[0004] In 2019, Zhang et al. (J. Am. Chem. Soc., 2019, 141: 18271) developed a simple method for controllable synthesis of imine spherical COFs at room temperature. The size of the microspheres can reach microns, and by changing the building blocks, a two-component spherical COF with an alkyne-modifiable site was synthesized. However, in the preparation of stationary phases, the loading amount of the selector on the matrix material is not the more the better, and too much selector will block the pores of the matrix material and increase its mass transfer resistance, thereby affecting its separation performance. For COF materials, the modifiable sites are often distributed in one-dimensional pores, and too many modifiable sites will often make the one-dimensional pores smaller, affecting the entry of modifiers into the pores and affecting their application. It is worth noting that Jiang et al. (Nat. Chem., 2015, 7: 905) reported a non-spherical three-component [HC≡C] x-TPB-DMTP-COF, by changing the ratio of BPTA and DMTA feeding amount, the number of alkyne-modifiable sites on the three-component COF material can be adjusted. However, the COF material with non-spherical morphology has the problems of poor mechanical strength, uneven particle size, etc., which limits its application in HPLC stationary phase.

[0005] Although spherical COF has been proved to be a potential stationary phase matrix material with application potential, a coated spherical COF-based stationary phase can be prepared by coating a cellulose derivative and other selection agents to realize its application in high performance liquid chromatography (HPLC) separation (J. Chromatogr. A, 2022, 1675:463155). However, the coated spherical COF-based stationary phase has the disadvantages of easy falling off of selection agents, poor stability, short service life, etc. Therefore, it has great research significance and application value to develop a bonded spherical COF-based high performance liquid chromatography stationary phase with more excellent stability. SUMMARY

[0006] An object of the present application is to solve the above technical problems, and provide a preparation method of a bonded imine three-component spherical COF-based stationary phase, which has a simple and convenient synthesis process, and the prepared bonded imine three-component spherical COF-based stationary phase has good stability and good application prospect in HPLC separation.

[0007] In order to achieve the above object of the application, the present application provides a preparation method of a bonded imine three-component spherical COF-based stationary phase, comprising the following steps:

[0008] S1: synthesizing an imine three-component spherical COF containing an alkyne group bonding arm, the structural formula of which is:

[0009]

[0010] S2: bonding monosubstituted 6-azido-6-deoxy-3,5-dimethoxy aniline carbamoyl β-cyclodextrin to the three-component spherical COF prepared in step S1 by click chemistry method to prepare a bonded imine three-component spherical COF-based chiral stationary phase.

[0011] Compared with the prior art, the imine-based three-component spherical COF containing an alkyne group bonding arm is first synthesized as a matrix material, and a monosubstituted 6-azido-6-deoxy-3, 5-dimethoxy aniline carbamoylated β-cyclodextrin (β-CD derivative) is bonded to the three-component SCOF matrix by a click chemistry method to prepare a bonded imine-based spherical COF-based chiral stationary phase (β-CD SCOF). The synthesis method is simple, convenient and has few synthesis steps. The bonded imine-based three-component spherical COF-based stationary phase has excellent chemical stability, and has good application prospects in HPLC separation, and is expected to broaden the types and range of applicable mobile phases.

[0012] Preferably, in step S2, the mass ratio of the monosubstituted 6-azido-6-deoxy-3, 5-dimethoxy aniline carbamoylated β-cyclodextrin to the three-component spherical COF is 3:2.

[0013] Preferably, step S1 comprises the following steps: dissolving 2, 5-bis (prop-2-alkyn-1-yl) p-phenylenediformyl, 2, 5-dimethoxy-p-phenylenediformyl and 1, 3, 5-tri (aminophenyl) benzene in acetonitrile and ultrasonicating, after complete dissolution, quickly adding an aqueous acetic acid solution with a concentration of 12M and vortexing for 10s, and reacting at room temperature for 72h; then filtering to obtain a yellow precipitate, washing with EtOH three times, and drying at 60℃ under vacuum for 12h to obtain the imine-based three-component spherical COF containing an alkyne group bonding arm.

[0014] Preferably, step S2 comprises the following steps:

[0015] S21: placing the three-component spherical COF prepared in step S1 in a Schlenk reaction bottle, adding toluene and tert-butyl alcohol as a reaction solution, and then ultrasonicating and dispersing;

[0016] S22: adding N, N-diisopropyl ethylamine and sealing, and then removing oxygen by vacuum pumping with liquid nitrogen, and repeating the oxygen removal twice;

[0017] S23: after the Schlenk reaction bottle is filled with argon, the cap is opened, CuI is added, and then oxygen is removed by vacuum pumping with liquid nitrogen, and the oxygen removal is repeated twice;

[0018] S24: taking the monosubstituted 6-azido-6-deoxy-3, 5-dimethoxy aniline carbamoylated β-cyclodextrin, dissolving it in toluene and removing oxygen, then adding it dropwise to the reaction solution obtained in step S23, removing oxygen by vacuum pumping with liquid nitrogen, and repeating the oxygen removal twice, and then stirring at room temperature (25-50℃) for 48h;

[0019] S25: The obtained solution is filtered to obtain a yellow-brown solid, which is rinsed with a 5% acetic acid acetonitrile solution and then with ethanol or anhydrous ethanol, and dried overnight to obtain a bonded imine three-component spherical COF-based chiral stationary phase.

[0020] Preferably, in step S1, the molar ratio of 2,5-bis(prop-2-yn-1-yloxy)benzene-1,4-dicarboxaldehyde, 2,5-dimethoxy-benzene-1,4-dicarboxaldehyde and 1,3,5-tris(aminophenyl)benzene is 3:3:4. The molar ratio of the three components is best controlled at 3:3:4, and the obtained three-component spherical COF bonding site is most suitable.

[0021] Preferably, in step S1, the volume ratio of acetonitrile to 12M aqueous acetic acid solution is 50:1.

[0022] Preferably, in step S21, the volume ratio of toluene to tert-butyl alcohol is 4:1.

[0023] The application also provides a bonded imine three-component spherical COF-based stationary phase prepared by the above preparation method.

[0024] The application also provides a bonded β-cyclodextrin spherical COF chromatographic column, whose stationary phase is the above-mentioned bonded imine three-component spherical COF-based stationary phase.

[0025] The application also provides the use of the above-mentioned bonded β-cyclodextrin spherical COF chromatographic column in the high-performance liquid chromatography separation of polycyclic aromatic hydrocarbon compounds.

[0026] The application first uses a three-component synthesis strategy to synthesize a new imine three-component spherical COF with an alkyne group by taking BPTA, DMTA and TAPB as building units, and then bonds a monosubstituted 6-azido-6-deoxy-3,5-dimethoxyphenylcarbamoylated β-cyclodextrin to the SCOF matrix through a click chemistry method to prepare a bonded chiral stationary phase β-CD SCOF, which is used in HPLC separation. The obtained bonded β-CD SCOF chromatographic column shows good separation performance for two polycyclic aromatic hydrocarbon compounds (acenaphthene and pyrene, and acenaphthene and phenanthrene) in HPLC, and its stability is good, and the results of continuous 10 injections and month-long detection are basically consistent. The application provides an application direction of SCOF with high stability, porosity and high crystallinity, and also proves that SCOF has good application prospects as a chiral stationary phase matrix material in HPLC separation. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 Synthetic route of imine three-component spherical COF with alkyne group-containing bonding arm

[0028] Figure 2Synthesis process flow chart for bonded β-CD spherical COF stationary phase

[0029] Figure 3 Fourier transform infrared spectra of imine-based three-component SCOF with alkyne group-containing bonding arm prepared for BPTA, DMTA and TAPB Example 1

[0030] Figure 4 Fourier transform infrared spectra of three-component SCOF, β-CD derivative and β-CD SCOF prepared in Example 1

[0031] Figure 5 X-ray powder diffraction spectra of three-component SCOF, β-CD derivative and β-CD SCOF prepared in Example 1

[0032] Figure 6 Thermogravimetric analysis curve of three-component SCOF, β-CD derivative and β-CD SCOF prepared in Example 1

[0033] Figure 7 Nitrogen isothermal adsorption-desorption curve of three-component SCOF and β-CD SCOF prepared in Example 1

[0034] Figure 8 Pore size distribution of three-component SCOF and β-CD SCOF prepared in Example 1

[0035] Figure 9 Scanning electron micrographs of three-component SCOF (a), (b) and β-CD SCOF (c), (d) prepared in Example 1

[0036] Figure 10 Transmission electron micrographs of three-component SCOF (a), (b) and β-CD SCOF (c), (d) prepared in Example 1

[0037] Figure 11 X-ray powder diffraction spectra of β-CD SCOF prepared in Example 1 before and after soaking in different non-conventional mobile phases

[0038] Figure 12 High performance liquid chromatograms obtained from separation of polycyclic aromatic hydrocarbons (acenaphthene and pyrene) (a) and polycyclic aromatic hydrocarbons (acenaphthene and phenanthrene) (b) using bonded β-CD SCOF column prepared in Example 2

[0039] Figure 13 High performance liquid chromatograms obtained from continuous injection of 10 injections of polycyclic aromatic hydrocarbons (acenaphthene and pyrene) (a) and polycyclic aromatic hydrocarbons (acenaphthene and phenanthrene) (b) using bonded β-CD SCOF column prepared in Example 2

[0040] Figure 14High performance liquid chromatograms obtained by injecting polycyclic aromatic hydrocarbons (acenaphthene and pyrene) (a) and polycyclic aromatic hydrocarbons (acenaphthene and phenanthrene) (b) into the bonded β-CD SCOF column prepared in Example 2 every other month DETAILED DESCRIPTION

[0041] The application will be further described with reference to the following examples. It should be appreciated that the application is not limited in scope by the examples described which are intended as illustrations only. Any form of variation or modification which becomes apparent to one skilled in the art upon reading the present disclosure is intended to be within the scope of the application.

[0042] In the present application, the raw materials and reagents used are shown in Table 1, and the main experimental instruments and equipment are shown in Table 2. Unless otherwise specified, the reagents and raw materials used in the present application are commercially available, and the purity is all analytical pure.

[0043] Table 1 Raw materials and reagents

[0044]

[0045]

[0046] Table 2 Main experimental instruments and equipment

[0047]

[0048] Example 1:

[0049] This example prepares a bonded imine-based three-component spherical COF-based stationary phase according to the following steps:

[0050] S1: Synthesis of imine-based three-component spherical COF containing alkyne group bonding arm: please refer to Figure 1 , 2,5-bis(prop-2-yn-1-yloxy)benzene-1,4-dicarboxaldehyde (BPTA, 6.7 mg, 0.03 mmol), 2,5-dimethoxy-benzene-1,4-dicarboxaldehyde (DMTA, 5.9 mg, 0.03 mmol) and 1,3,5-tris(aminophenyl)benzene (TAPB, 14 mg, 0.04 mmol) were placed in a 10 mL glass bottle, acetonitrile (5 mL) was added and ultrasonicated, and after complete dissolution, 12M acetic acid (100 μL) was quickly added and vortexed for 10 s, and reacted at room temperature for 72 h. A yellow precipitate was obtained by filtration, washed with EtOH three times, and dried at 60°C under vacuum overnight to obtain the three-component SCOF (18.0 mg, yield: 72%).

[0051] S2: please refer to Figure 2SCOF (200 mg) was placed in a 50 mL Schlenk flask, toluene (16 mL) and t-butyl alcohol (4 mL) were added as the reaction solution and ultrasonically dispersed. N,N- diisopropylethylamine (DIPEA, 0.8 mL) was added, sealed with a rubber plug, and deoxygenated by vacuum-pumping with liquid nitrogen cooling for 2 cycles. After the Schlenk flask was filled with argon, CuI (60 mg) was added and deoxygenated by vacuum-pumping with liquid nitrogen cooling for 2 cycles. The β-CD derivative (monosubstituted 6-azido-6-deoxy-3,5-dimethoxyphenylcarbamoylated β-cyclodextrin) (300 mg) was previously dissolved in toluene (2.5 mL) and deoxygenated by bubbling with argon for 30 min, and the solution was added dropwise to the reaction system, deoxygenated by vacuum-pumping with liquid nitrogen cooling for 2 cycles, and stirred at room temperature for 48 h. A tan solid was obtained by filtration, washed with 5% acetic acid in acetonitrile, and then with ethanol, and dried overnight to obtain the bonded β-CD SCOF stationary phase.

[0052] In step S2, the β-CD derivative (monosubstituted 6-azido-6-deoxy-3,5-dimethoxyphenylcarbamoylated β-cyclodextrin) was prepared as follows:

[0053] (1) Synthesis of monosubstituted 6-p-toluenesulfonyl β-CD: β-CD (7.0 g) and p-toluenesulfonyl chloride (7.0 g) were placed in deionized water (100 mL) and stirred for 1 h, 20% sodium hydroxide solution (20 mL) was added and stirring was continued for 5 min, then filtered to collect the filtrate. The pH was adjusted to 10 with dilute hydrochloric acid, and a white precipitate was separated out, which was filtered off and dried to obtain monosubstituted 6-p-toluenesulfonyl β-CD.

[0054] (2) Synthesis of monosubstituted 6-azido-6-deoxy-β-CD: Monosubstituted 6-p-toluenesulfonyl β-CD (6.0 g) and sodium azide (6.0 g) were placed in deionized water (300 mL), and stirred at 80°C for 8 h. Then, the reaction solution was concentrated, 1,1,2,2-tetrachloroethane (5 mL) was added, and after stirring and filtering, a white precipitate was obtained, which was monosubstituted 6-azido-6-deoxy-β-CD.

[0055] Example 2:

[0056] The bonded β-CD spherical COF chromatographic column was prepared according to the following steps:

[0057] The bonded β-CD SCOF stationary phase (700 mg) prepared in Example 1 was ultrasonically dispersed in IPA (10 mL) for 10 min, and then poured into a homogenizing tank. The column tube (50 mm x 4.6 mm i.d.) was loaded with a displacement liquid of Hex:IPA (80 / 20, v / v) at 3625 psi. In order to obtain good reproducible results, the prepared column was flushed with the mobile phase to reach baseline equilibrium.

[0058] Analysis of test results:

[0059] The imine type three-component spherical COF containing alkyne bonding arms and the bonded spherical COF-based stationary phase β-CD SCOF obtained in Example 1 were subjected to a series of test characterization, and the test results were as follows:

[0060] Fourier infrared spectroscopy (FT-IR) test:

[0061] First, the chemical composition of the three-component COF was verified by FT-IR. As shown in Figure 3 , the spectrum of the three-component SCOF showed a characteristic peak of C≡C-H at 3286 cm -1 , and a characteristic peak of C≡C bond at 2123 cm -1 , indicating that the SCOF contained alkyne groups. And it can be seen that a typical C=N bond characteristic peak appeared at 1620 cm -1 , indicating that BPTA, DMTA and TAPB had undergone condensation reaction to synthesize the three-component SCOF.

[0062] Please refer to Figure 4 the Fourier infrared spectrum, compared with the three-component SCOF, the spectrum of β-CD SCOF showed that the characteristic peaks of C≡C-H and C≡C bond at 3289 cm -1 and 2123 cm -1 were weakened, indicating that the alkyne group of the SCOF indeed underwent click chemistry reaction. However, the above characteristic peaks did not completely disappear, which may be due to the large molecular size of the β-CD derivative, which is difficult to fully contact with the pore rich in modification sites, and cannot be completely replaced. While the newly formed C=N, C=C bonds at 1620 cm -1 and 1593 cm -1 and the characteristic peaks of the β-CD derivative overlapped with those of the three-component SCOF, and therefore were not reflected in the spectrum of the β-CD SCOF.

[0063] X-ray diffraction test

[0064] See Figure 5 , the PXRD pattern of the three-component SCOF shows five diffraction peaks at 2.7°, 4.7°, 5.4°, 7.2°, 9.5° and 25.3°, corresponding to (100), (110), (200), (210), (220) and (001) crystal planes, respectively. The PXRD pattern of the β-CD SCOF with the β-CD derivative bonded shows five diffraction peaks at 2.7°, 4.6°, 5.5°, 7.3°, 9.7° and 25.3°, which are basically consistent with those of the three-component SCOF, but the intensity of the diffraction peaks is decreased, which is a relatively common phenomenon for the post-modified COF materials. In addition, the spectrum of the β-CD derivative has a relatively wide diffraction peak at 2θ = 4.5°, while this peak does not appear in the PXRD spectrum of the β-CD SCOF, indicating that there is no free β-CD derivative in the β-CD SCOF.

[0065] Thermogravimetric analysis (TGA)

[0066] The thermal stability of the three-component SCOF, the β-CD SCOF and the β-CD derivative was further determined by thermogravimetric analysis (TGA). The test was carried out under nitrogen atmosphere at a temperature rise rate of 10 ℃ min -1 -1 Figure 6 . The results are shown in . The three-component SCOF has no obvious weight loss turning point in the range of 30 to 380 ℃, indicating that it has good thermal stability at 380 ℃. Different from this, the β-CD SCOF and the β-CD derivative have no obvious weight loss in the range of 30 to 150 ℃, and show similar weight loss in the range of 150 to 345 ℃, which is caused by the decomposition of the same structure of the β-CD SCOF and the β-CD derivative. The content of the β-CD derivative in the β-CD SCOF is calculated to be 8.2% of the total mass from the weight loss degree of the β-CD SCOF. Moreover, the descending trend of the curve of the β-CD SCOF after 345 ℃ is consistent with that of the three-component SCOF, and it can be seen from the curves of the three that the β-CD derivative is successfully compounded on the three-component SCOF.

[0067] Characterization of specific surface area and porosity

[0068] The characterization of the specific surface area and porosity of the three-component SCOF and the β-CD SCOF was obtained by measuring the nitrogen isothermal adsorption and desorption experiment of the completely activated sample at 77 K. As shown in Figure 7 , the adsorption and desorption isotherm curves of the SCOF and the β-CD SCOF are consistent with the typical type I adsorption and desorption isotherm, and the BET specific surface areas of the two are 1363 m 2 g -1 and 207 m 2 g , respectively.g -1 This further demonstrates that the bonding of β-CD derivatives to the three-component SCOF reduces the specific surface area of ​​the resulting β-CD SCOF.

[0069] Aperture distribution calculation

[0070] Further calculations using nonlocal density functional theory revealed that the pore size distributions of both the tricomponent SCOF and β-CD SCOF are primarily concentrated around 2.0 nm. Figure 8 As shown. This may be because the β-CD derivative has a large molecular size, making it difficult to enter the one-dimensional channels of SCOF. It mainly bonds with the exposed alkyne groups on the surface of the three-component SCOF microspheres, so the pore size did not change before and after modification.

[0071] Scanning electron microscopy (SEM) characterization

[0072] The microstructures of the three-component SCOF and β-CD SCOF were characterized by scanning electron microscopy (SEM), such as... Figure 9 As shown in 9a and 9b, the three-component SCOF exhibits a relatively uniform and regular spherical morphology with an average particle size of 1.5 μm. The microstructure of the bonded β-CDSCOF is shown in Figure 9b. Figure 9 As shown in c and 9d, the morphology did not change significantly, although the particle size increased slightly. This may be because the bonded β-CD derivative is not a high-molecular-weight polymer and cannot form a distinct rough shell. However, this uniform and regular spherical morphology is very important for the stationary phase matrix material, as it helps improve column efficiency and thus achieve better separation results.

[0073] Transmission electron microscopy (TEM) characterization

[0074] The three-component SCOF and β-CD SCOF were characterized by transmission electron microscopy (TEM). Figure 10 TEM images of the three-component SCOF (a and 10b) show that the three-component SCOF is a solid microsphere with a shell layer of approximately 100 to 200 nm thickness on its surface. The TEM image of β-CD SCOF (...) Figure 10c and 10d) exhibited a thicker shell (200 to 280 nm) than the three-component SCOF, and the particle size of the spheres was also slightly larger than that of the three-component SCOF. This may be because the β-CD derivative is bonded to the surface of the three-component SCOF microspheres, making its original shell thicker, thus resulting in a more obvious shell in β-CD SCOF than in the three-component SCOF. However, during the imaging of β-CD SCOF, a small number of microspheres with indistinct shells could still be found. This may be because during the click chemistry reaction, the β-CD derivative and a small number of modifiable sites in the three-component SCOF did not make sufficient contact and could not completely replace them.

[0075] Stability testing in unconventional mobile phases

[0076] To investigate the stability of β-CD SCOF in unconventional mobile phases, β-CD SCOF was immersed in DMF, EA, THF, and DCM for 3 days, respectively. The stability was verified by comparing the PXRD spectra of the COF materials before and after immersion. Figure 11 As shown, the PXRD spectra of β-CD SCOF after soaking in different unconventional mobile phases showed no significant changes. Five diffraction peaks at 2θ = 2.7°, 4.6°, 5.5°, 7.3°, 9.7°, and 25.3° remained consistent, indicating that these unconventional mobile phases did not decrease the crystallinity of β-CD SCOF. The results are consistent with FT-IR, further demonstrating that the synthesized β-CD SCOF stationary phase has excellent chemical stability.

[0077] Furthermore, the bonded β-CD SCOF column prepared in Example 2 was subjected to the following separation performance and stability tests to demonstrate its application prospects. Since polycyclic aromatic hydrocarbons (PAHs) have varying UV absorption wavelengths, the detection wavelength of the PDA detector was determined based on the combination of PAHs to obtain relatively similar peak heights and areas. Specifically, the detection wavelength for acenaphthene and pyrene was 230 nm, and the detection wavelength for acenaphthene and phenanthrene was 276 nm. The sample was prepared using ethanol as the solvent, with an injection volume of 10 μL and an injection concentration of 0.1 mg / mL. -1 .

[0078] Separation performance test of bonded β-cyclodextrin spherical COF column

[0079] To evaluate the separation performance of the bonded β-CD SCOF column prepared in Example 2 in HPLC, two groups of polycyclic aromatic hydrocarbons (acenaphthene and pyrene, acenaphthene and phenanthrene) were separated by HPLC using a Hex / EtOH mixed eluent as the mobile phase. The chromatographic conditions were: Hex / EtOH (97 / 3, v / v) as the mobile phase, and a flow rate of 0.3 mL / min. -1 Separation was performed at a column temperature of 35℃. The chromatogram is shown below.Figure 12 As shown in Figure 6, acenaphthene and pyrene can reach baseline separation on the bonded β-CD SCOF column within 40 min with a separation factor of 1.71, while acenaphthene and phenanthrene can also reach near baseline separation on the bonded β-CD SCOF column with a separation factor of 1.34. Figure 12 As shown in Figure 6, acenaphthene and pyrene can reach baseline separation on the bonded β-CD SCOF column within 40 min with a separation factor of 1.71, while acenaphthene and phenanthrene can also reach near baseline separation on the bonded β-CD SCOF column with a separation factor of 1.34.

[0080] Stability test of the bonded β-CD SCOF column

[0081] The bonded β-CD SCOF column prepared in Example 2 was subjected to a stability test, and two kinds of polycyclic aromatic hydrocarbons (acenaphthene and pyrene, acenaphthene and phenanthrene) were subjected to continuous injection for 10 injections and detection after one month, respectively. The chromatographic conditions were as follows: Hex / EtOH (97 / 3, v / v) was used as the mobile phase, the flow rate was 0.3 mL min -1 , and the column temperature was 35 °C. As shown in Figure 7, in the continuous injection test of the bonded β-CD SCOF column, acenaphthene and pyrene on the bonded β-CD SCOF column can maintain consistent chromatographic peak shape, retention and separation. Figure 13 As shown in Figure 7, acenaphthene and phenanthrene can also achieve the same effect (b), which shows that the bonded β-CD SCOF column can maintain short-term stability. As shown in Figure 7, in the detection after one month of use, even after three months of uninterrupted use, the separation of acenaphthene and pyrene, and acenaphthene and phenanthrene on the bonded β-CD SCOF column can maintain their chromatographic peak shape, retention, and separation, which shows that the bonded β-CD SCOF column has good long-term durability, which is due to the high stability and good solvent resistance of the COF material itself. Figure 13 Figure 14

[0082] ​​Compared with the prior art, the application firstly adopts a three-component synthesis strategy, synthesizes a new imine three-component spherical COF with an alkyne group at normal temperature by taking BPTA, DMTA and TAPB as building units, then bonds monosubstituted 6-azido-6-deoxy-3, 5-dimethoxy aniline carbamoyl β-cyclodextrin to the SCOF matrix through a click chemistry method, prepares a bonded chiral stationary phase β-CD SCOF, and applies the bonded chiral stationary phase β-CD SCOF to HPLC separation. The bonded β-CD SCOF chromatographic column prepared by adopting the β-CD SCOF as a stationary phase shows good separation performance in HPLC for two polycyclic aromatic hydrocarbon compounds (acenaphthene and pyrene, and acenaphthene and phenanthrene). Meanwhile, the influence of HPLC chromatographic conditions on separation is studied, and the results of continuous 10-injection sampling and month-detected sampling are basically consistent, which shows that the bonded β-CD SCOF has strong stability and durability. The application not only can promote the application of SCOF with high stability, porosity and high crystallinity, but also proves that the SCOF has good application prospect as a chiral stationary phase matrix material in the direction of HPLC separation.

[0083] The application is not limited to the use listed in the specification and embodiments, and can be fully applied to various fields suitable for the application, and other modifications and changes can be easily realized by those skilled in the art without departing from the spirit and essence of the application, but the corresponding modifications and changes should all belong to the protection scope required by the application.

[0084] The above only describes some embodiments of the application, and does not limit the embodiments and protection scope of the application. Those skilled in the art should realize that any equivalent replacement and obvious change made according to the content of the specification of the application should be included in the protection scope of the application.

Claims

1. A method for preparing a bonded imine-based three-component spherical COF-based stationary phase, characterized by: The bonded imine three-component spherical COF-based stationary phase is used for separating polycyclic aromatic hydrocarbon compounds, acenaphthene, pyrene and phenanthrene, in high performance liquid chromatography, and the preparation method comprises the following steps: S1: synthesizing an imine three-component spherical COF containing an alkyne group bonding arm, and the structural formula is: S2: bonding monosubstituted 6-azido-6-deoxy-3,5-dimethoxy anilino carbamated β-cyclodextrin to the three-component spherical COF prepared in step S1 by a click chemistry method to prepare a bonded imine three-component spherical COF-based chiral stationary phase; The mass ratio of the monosubstituted 6-azido-6-deoxy-3,5-dimethoxy anilino carbamated β-cyclodextrin to the three-component spherical COF is 3:

2.

2. The method of claim 1, wherein: Step S1 comprises the following steps: dissolving 2,5-bis(prop-2-yn-1-yloxy) p-xylene dicarboxaldehyde, 2,5-dimethoxy-p-xylene dicarboxaldehyde and 1,3,5-tris(aminophenyl) benzene in acetonitrile and ultrasonicating, after complete dissolution, quickly adding an aqueous acetic acid solution with a concentration of 12M and vortexing for 10s, and reacting for 72h at room temperature; then filtering to obtain a yellow precipitate, washing three times with EtOH, and drying at 60°C under vacuum for 12h to obtain the imine three-component spherical COF containing an alkyne group bonding arm.

3. The method of claim 1, wherein: Step S2 comprises the following steps: S21: placing the three-component spherical COF prepared in step S1 in a Schlenk reaction bottle, adding toluene and tert-butyl alcohol as a reaction solution, and then ultrasonicating and dispersing; S22: adding N,N-diisopropylethylamine and sealing, and then removing oxygen by vacuumizing under liquid nitrogen, and repeating the oxygen removal for 2 times; S23: after the Schlenk reaction bottle is filled with argon, the cap is opened, CuI is added, and then oxygen is removed by vacuumizing under liquid nitrogen, and the oxygen removal is repeated for 2 times; S24: taking the monosubstituted 6-azido-6-deoxy-3,5-dimethoxy anilino carbamated β-cyclodextrin, which is previously dissolved in toluene and oxygen is removed, and then adding dropwise to the reaction solution obtained in step S23, removing oxygen by vacuumizing under liquid nitrogen, and repeating the oxygen removal for 2 times, and then stirring for 48h at room temperature; S25: filtering the obtained solution to obtain a yellow-brown solid, rinsing with an acetonitrile solution containing 5% acetic acid, rinsing with ethanol, and drying overnight to obtain the bonded imine three-component spherical COF-based chiral stationary phase.

4. The method of claim 2, wherein: In step S1, the molar ratio of the 2,5-bis(prop-2-yn-1-yloxy) p-xylene dicarboxaldehyde, 2,5-dimethoxy-p-xylene dicarboxaldehyde and 1,3,5-tris(aminophenyl) benzene is 3:3:

4.

5. The method of claim 4, wherein: In step S1, the volume ratio of the acetonitrile to the aqueous acetic acid solution with a concentration of 12M is 50:

1.

6. The method of claim 3, wherein: In step S21, the volume ratio of toluene to tert-butyl alcohol is 4:

1.

7. The bonded imine three-component spherical COF-based stationary phase prepared by the preparation method in any one of claims 1-6.

8. A bonded beta-cyclodextrin spherical COF chromatographic column characterized by: The stationary phase thereof adopts the bonded imine three-component spherical COF-based stationary phase in claim 7.

9. Application of the bonded β-cyclodextrin spherical COF chromatographic column in claim 8 in separating polycyclic aromatic hydrocarbon compounds, acenaphthene, pyrene and phenanthrene, in high performance liquid chromatography.

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