基于共价有机框架材料TpPa-NH2-Glu的高效液相色谱固定相用于分离手性化合物

共价有机框架材料（COFs）是一类由多齿有机单元通过共价键连接而成的新兴孔晶体材料。通过合成后修饰所得到的COFs通常具有较高的结晶度与孔隙率，并且在手性拆分、不对称催化与色谱分析等领域具有良好的应用价值。该文用1，3，5-三甲醛间苯三酚与2-硝基-1，4-苯二胺合成TpPa-NO₂，对其还原得到TpPa-NH₂，然后通过合成后修饰策略将D-葡萄糖修饰到该材料上，得到手性材料TpPa-NH₂的D-葡萄糖衍生物（TpPa-NH₂-Glu）。利用“网包法”将其固载在球形硅胶表面用作高效液相色谱固定相并制备了液相色谱柱，分别以正己烷-异丙醇（9∶1， v/v）或甲醇-水（9∶1， v/v）为流动相，流速0.5 mL/min，成功拆分了16种包括多个手性药物的外消旋体和2种苯系位置异构体o，m，p-硝基苯胺和o，m，p-碘苯胺。在甲醇-水（9∶1， v/v）流动相条件下，拆分了5种外消旋体，其中盐酸普萘洛尔、华法林、美托洛尔达到了基线分离；在正己烷-异丙醇（9∶1， v/v）流动相条件下，拆分了11种外消旋体，其中2-溴丙酸乙酯、3-丁炔-2-醇达到了基线分离。此外还探究了温度对TpPa-NH₂-Glu液相色谱柱的影响以及TpPa-NH₂-Glu液相色谱柱的重复性，结果表明，温度对TpPa-NH₂-Glu所制备的高效液相色谱柱影响不大，且TpPa-NH₂-Glu所制备的高效液相色谱柱具有良好的重复性，其相对标准偏差（RSD）分别为1.55%和1.46%。实验结果表明，TpPa-NH₂-Glu对手性化合物有良好的拆分能力。

Separation of chiral compounds using high performance liquid chromatography stationary phase based on covalent organic framework material TpPa-NH2-Glu

Covalent organic frameworks （COFs） are an emerging class of porous crystalline materials composed of multidentate organic units connected by covalent bonds. COFs have been demonstrated to exhibit great potential and research value in many fields， including gas storage and separation， photoelectric devices， fluorescence sensors， catalysis， drug delivery， dye and pollutant adsorption， and electronic devices， and so on. The COFs obtained by post-synthesis modification tend to exhibit high crystallinities and porosities， thereby rendering them suitable materials for use in the fields of chiral resolution， asymmetric catalysis， and chromatography. In this work， TpPa-NO₂ was synthesized from 1，3，5-tricarbaldehyde phloroglucinol and 2-nitro-1，4-phenylenediamine， which was then reduced to TpPa-NH₂. Subsequently， this material was modified with D-glucose via a post-synthesis modification strategy to obtain the TpPa-NH₂-Glu. TpPa-NH₂-Glu were characterized by nuclear magnetic resonance （NMR） spectroscopy， Fourier transform-infrared （FT-IR） spectroscopy， X-ray powder diffraction （XRD） analysis， etc. In the XRD pattern， the peaks observed at 4.7°， 8.1°， 11.1°， and 27° were attributed to the TpPa-NH₂-Glu， and these peaks are consistent with previous reports， thereby confirming the successful synthesis of this derivative. In addition， circular dichroism experiments indicated that the TpPa-NH₂-Glu exhibited a Cotton effect， further confirming the chiral COF was prepared. Subsequently， this material was immobilized on the surface of spherical silica gel particles via the net-wrapping method to prepare a stationary phase for high performance liquid chromatographic column. Using n-hexane-isopropanol （9∶1， v/v） or methanol-water （9∶1， v/v） as mobile phases at a flow rate of 0.5 mL/min， 16 racemates and two benzene-based positional isomers （o，m，p-nitroaniline and o，m，p-Iodoaniline） were successfully resolved by this chiral column. In addition， under methanol-water （9∶1， v/v） mobile phase conditions， five racemates were separated， among which propranolol hydrochloride， warfarin， and metoprolol reached baseline separation. Furthermore， under n-hexane-isopropanol （9∶1， v/v） mobile phase conditions， 11 racemates were resolved， among which ethyl 2-bromopropionate and 3-butyn-2-ol reached baseline separation. Meanwhile， the effect of temperature on the TpPa-NH₂-Glu liquid chromatography column and the repeatability of the TpPa-NH₂-Glu liquid chromatography column were also explored. The HPLC column prepared by TpPa-NH₂-Glu had good repeatability， and its relative standard deviation （RSD） was 1.55% and 1.46%， respectively. It is demonstrated that the TpPa-NH₂-Glu material has good resolution ability for chiral compounds.