Preparation And Evalution Of Novel Imidazolium Ionic Liquid Chiral Stationary Phase And Asymmetrical Peptoid Chiral Stationary Phase

Ionic liquids have been widely used in various fields due to their excellent physical and chemical properties.Chiral ionic liquids have the potential for chiral recognition and have potential applications in chiral separation of liquid chromatography.Cyclohexene oxide was used as a chiral precursor to synthesize a series of imidazole cyclohexanol derivatives in this study.Then,a novel type of imidazole ionic liquid chiral stationary phase was perpared and successfully applied to the separation of chiral acidic compounds.In this thesis,seven different structures of chiral ionic liquids were designed and synthesized,and detailed chiral separations were evaluated.The effects of the changes in the structure of the 1-and 2-position groups in the chiral selectors on the chiral selectivity were investigated.The results showed that the introduction of a hydrogen-bond donor group at the 1-position is beneficial to the improvement of the chiral selectivity of the stationary phase.The bring in of the dimethyl benzimidazole group in the 2-position is advantageous.Afterwards,the effects of mobile phase composition and additives concentration,type,ratio and other factors on the chiral separation were investigated,and it was proved that the main force of retention of the acidic sample on this type of stationary phase was ion exchange.Finally,the chiral separation mechanism of the chiral chiral enantiomers in this type of chiral stationary phase was discussed,demonstrating the need for hydrogen bonding,?-?interactions,ion exchange,and steric hindrance for chiral separation.Force synergy to make the sample split.In addition,based on the L-proline derivatives as chiral side chain,an asymmetrical disubstituted peptoid chiral stationary phases was designed.First,the effect of differential substituent structure on chiral selectivity was investigated.Then,the relationshio between the structure of chiral selective agent,the mobile phase,the temparation and the selectivity were studied.The mechanism of chiral recognition was also disscussed.