Application of Cyclam-Capped β-Cyclodextrin-Bonded Silica Particles as a Chiral Stationary Phase in Capillary Electrochromatography for Enantiomeric Separations
作者:Yinhan Gong、Hian Kee Lee
DOI:10.1021/ac0204909
日期:2003.3.1
Two novel types of substituted cyclam-capped β-cyclodextrin (β-CD)-bonded silica particles have been prepared and used as chiral stationary phases in capillary electrochromatography (CEC). The two stationary phases have a chiral selector with three recognition sites: β-CD, cyclam, and the latter's sidearm. They exhibit excellent enantioselectivities in CEC for a wide range of compounds as a result of the cooperative functioning of the anchored β-CD and cyclam. After inclusion of the metal ion (Ni2+) from the running buffer into the substituted cyclams and their sidearm ligands, the bonded stationary phases become positively charged and can provide extra electrostatic interactions with ionizable solutes and enhance the dipolar interactions with some polar neutral solutes. This enhances the host−guest interaction with some solutes and improves chiral recognition and enantioselectivity. These new types of stationary phases exhibit great potential for fast chiral separations in CEC.
两种新型取代的环烷基顶端β-环糊精(β-CD)键合二氧化硅颗粒已被制备并用于毛细管电色谱(CEC)中的手性固定相。这两种固定相具有一个包含三个识别位点的手性选择剂:β-CD、环烷基和环烷基的侧链。它们在CEC中对广泛化合物表现出优异的对映选择性,原因在于锚定的β-CD和环烷基的协同作用。在运行缓冲液中金属离子(Ni2+)被包含到取代的环烷基及其侧链配体后,键合的固定相变为正电荷,从而能够与可电离溶质提供额外的静电相互作用,并增强与一些极性中性溶质的偶极相互作用。这增强了与某些溶质的宿主-客体相互作用,提高了手性识别和对映选择性。这些新型固定相在CEC中展现出快速手性分离的巨大潜力。