多孔有机笼(POC)是一种独特类型的微孔材料,由具有内部空腔的离散分子组成,可与各种化合物接触。在这项研究中,通过缩合合成了具有良好热化学稳定性的棱柱形手性POC(1R,2R)-二氨基环己烷和3,3',5,5'-teturonic-4,4'-联苯二酚通过希夫碱反应并通过质子核磁共振波谱表征,红外(IR)光谱,热重分析(TGA),和扫描电子显微镜。POC的IR光谱在1635cm-1处显示出强烈的特征吸收峰,表明它形成了亚胺键(C=N)。3425cm-1处的吸收峰归因于-OH的拉伸振动,2925和2858cm-1处的吸收峰归因于N=C-H和C-H的拉伸振动,1446和1383cm-1处的吸收峰归因于苯环中C=C-H和C=C的拉伸振动。POC的高分辨率质谱分析显示在m/z1363.7228处的分子离子峰,表明其成功合成。在25至800℃以10℃/min的速率进行TGA,分析结果表明,POC在300℃左右是稳定的。将POC溶解在二氯甲烷中,通过动态涂覆法均匀涂覆在石英毛细管内壁上,制备毛细管电色谱柱。实验结果表明,手性电色谱柱不仅能很好地分解氧氟沙星,Troger的基地,2-氨基-1-丁醇,和1-苯基-1-戊醇,但也分离了o-的异构体,m-,和对甲苯胺和o-,m-,和对氯苯胺,很好的手性分离能力。氧氟沙星最佳分离条件的研究,Troger的基地,2-氨基-1-丁醇,和1-苯基-1-戊醇揭示了电压,缓冲溶液浓度,和pH显著影响它们的分离度。特别是,氧氟沙星的最佳分离电压,Troger的基地,2-氨基-1-丁醇为15kV,而1-苯基-1-戊醇为17kV。氧氟沙星的最佳缓冲液浓度和pH值,Troger的基地,2-氨基-1-丁醇,1-苯基-1-戊醇为0.100mol/L和7.5mol/L。在最佳色谱条件下,氧氟沙星的分辨率值,Troger的基地,2-氨基-1-丁醇,和1-苯基-1-戊醇分别为1.80、3.33、1.69和1.18。结果表明,所制备的POC可以作为毛细管电色谱的良好手性固定相,具有一定的手性拆分能力,在色谱分离中具有良好的应用前景。
Porous organic cages (POCs) are a unique type of microporous materials composed of discrete molecules with internal cavities that are accessible to various compounds. In this study, a prismatic chiral POC with good thermochemical stability was synthesized by condensing (1R,2R)-diaminocyclohexane and 3,3\',5,5\'-teturonic-4,4\'-biphenediol via the Schiff base reaction and characterized by proton nuclear magnetic resonance spectroscopy, infrared (IR) spectroscopy, thermogravimetric analysis (TGA), and scanning electron microscopy. The IR spectrum of the POC revealed a strong characteristic absorption peak at 1635 cm-1, indicating that it formed imine bonds (C=N). The absorption peak at 3425 cm-1 was attributed to the stretching vibrations of -OH, the absorption peaks at 2925 and 2858 cm-1 were attributed to the stretching vibrations of N=C-H and C-H, and the absorption peaks at 1446 and 1383 cm-1 were attributed to the stretching vibrations of C=C-H and C=C in the benzene ring. High-resolution mass spectral analysis of the POC showed a molecular ion peak at m/z 1363.7228, indicating its successful synthesis. TGA was performed from 25 to 800 ℃ at a rate of 10 ℃/min, and the results of this analysis showed that the POC was stable up to approximately 300 ℃. The POC was dissolved in dichloromethane and uniformly coated on the inner wall of a quartz capillary via the dynamic coating method to prepare a capillary electrochromatographic column. The experimental results revealed that the chiral electrochromatographic column could not only resolve ofloxacin, Troger\'s base, 2-amino-1-butanol, and 1-phenyl-1-amyl alcohol but also separate the isomers of o-, m-, and p-toluidine and o-, m-, and p-chloroaniline, indicating its good chiral separation ability. Investigation of the optimal separation conditions for ofloxacin, Troger\'s base, 2-amino-1-butanol, and 1-phenyl-1-amyl alcohol revealed that the voltage, buffer solution concentration, and pH significantly affected their separation degree. In particular, the optimal separation voltage for ofloxacin, Troger\'s base, and 2-amino-1-butanol was 15 kV, while that for 1-phenyl-1-amyl alcohol was 17 kV. The optimal buffer concentration and pH for ofloxacin, Troger\'s base, 2-amino-1-butanol, and 1-phenyl-1-amyl alcohol were 0.100 mol/L and 7.5. Under optimal chromatographic conditions, the resolution values for ofloxacin, Troger\'s base, 2-amino-1-butanol, and 1-phenyl-1-pentanol were 1.80, 3.33, 1.69, and 1.18, respectively. The results collectively demonstrate that the prepared POC may serve as a good chiral stationary phase for capillary electrochromatography with a certain chiral resolution ability and has good application prospects in chromatographic separation.