Porous Liquid And Metal-organic Cage Used As Stationary Phase For Gas Chromatography

Novel porous solid materials exhibit unique properties,such as high specific surface area,permanent porosity,and high stability,and have been widely used in adsorption,separation,catalysis and other fields,mainly including metal-organic frameworks（MOFs）,covalent organic frameworks（COFs）,etc.Porous liquids（PLs）materials have attracted people’s attention in many fields because they combine the permanent pores of solid materials with the good fluidity and mass transfer of liquid.As a new type of porous crystal materials,metal-organic cages（MOCs）have an attractive advantage that is the atomic level control of metal coordination bonds,which leads to the adjustability and controllability of their structure in terms of clear shape,size and internal cavity.However,the application of PLs and MOCs in the field of chromatography is still in its infancy.It is the goal of researchers to design and synthesize new PLs and MOCs for enantioselective separation.In this paper,two different types of chiral PLs and a chiral MOC were synthesized as gas chromatographic stationary phase for preparing chromatographic columns to explore their separation performance.The specific contents are as follows:（1）The first chapter introduces the basic concept of chirality,the significance of resolution and resolution methods.Secondly,the concept of gas chromatography and the types of stationary phase are described.Finally,the concepts,synthesis strategies and applications of porous liquids and MOCs are summarized.（2）In the second chapter,a chiral metal-organic framework D-his-ZIF-8 was synthesized and dispersed in the steric hindrance solvent 1-butylpyridinium bis（trifluoromethanesulfonyl）imide（[Bpy][NTf₂]）to prepare the type III PL material D-his-ZIF-8-[Bpy][NTf₂].The chiral column was prepared using D-his-ZIF-8-[Bpy][NTf₂]as the stationary phase in gas chromatography.The column showed good separation performance for 12 chiral compounds including esters,ketones,ethers,alcohols,halogenated hydrocarbons and amino acid derivatives.This column also offered good separation performance for n-alkanes,n-alcohols,aromatic hydrocarbon mixtures and isomers.（3）In the third chapter,a type I PL（γ-CD-PL）based on cyclodextrin was prepared by chemical modification method and used as the stationary phase for preparing gas chromatography column by static method.The results showed that 11chiral compounds including esters,ethers,alcohols,aldehydes,organic acids,and amino acid derivatives were well separated on theγ-CD-PL column,which also exhibited good separation effect for mixture and isomer.（4）In the fourth chapter,the chiral ligand H₂L_Vconstructed from1,4,5,8-naphthalenetetracarboxylic dianhydride and L-valine was coordinated with Cu²⁺to form a chiral metal-organic cage MOC-V.A chiral column was prepared using the MOC-V as a stationary phase by static coating method for gas chromatography separation.The MOC-V chromatographic column not only shows excellent separation performance for n-alkane mixture,n-alcohol mixture and benzene series,but also has good separation performance for different kinds of isomers and enantiomers（e.g.,esters,halogenated hydrocarbons,alcohols,ethers,aldehydes and amino acid derivatives）.