Hydroxyl-functionalized Chiral Porous Organic Cages Used As Stationary Phases For Gas Chromatography

Porous organic cages(POCs)are an emerging class of porous molecular materials which self-assembled by discrete,shape-persistent,cage-like molecules through relatively weak intermolecular forces.POCs have recently received intensive interest in diverse fields due to their accessible intrinsic and extrinsic voids and good solubility in organic solvents.POCs can soluble in organic solvents,which make them convenient to prepare capillary columns with high efficiency and good reproducibility by static coating method.At present,there are few reports on chiral POCs used as chiral stationary phases(CSPs)for gas chromatography(GC),and their chiral resolution performance and types of substances that can be separated are also limited.The development of novel chiral POCs with different structures and functional groups as CSPs for GC is of great significance to improve the chiral resolution performance of POCs-based columns and broaden their applications.In this thesis,three kinds of hydroxyl functionalized chiral POCs were synthesized and used as stationary phase for the preparation of capillary GC columns.The main research contents are as follows:(1)In the introduction section,the basic concept of chirality,the significance of chiral separation and the methods of chiral separation are introduced firstly.Secondly,the GC and its CSPs and the preparation process of a capillary column are summarized.Finally,the POCs and their main synthesis methods and applications are introduced.(2)A hydroxyl functionalized chiral POC POC-1 was synthesized by Schiff base condensation of(1R,2R)-1,2-diphenylethylenediamine with2-hydroxy-1,3,5-triformylbenzene.It was used as stationary phase for the preparation of a capillary GC column by a static coating method.The fabricated column exhibits excellent chiral separation performance,and there are 39 pairs of enantiomers have been well resolved on the column.Compared with the commercial ?-DEX 120 column and previously reported chiral POCs-based columns(CC9,CC10 and CC3-R),this column shows better chiral separation ability and have prominent chiral recognition complementarity to these columns,which can broaden the chiral separation range of POCs-based chiral columns.In addition,the column also shows good separation performance for the separation of positional isomers,n-alkanes,n-alcohols and aromatics.(3)The hydroxyl functionalized homochiral POC POC-2 was synthesized by(1R,2R)-1,2-cyclohexanediamine and 2-hydroxy-1,3,5-triformylbenzene,which was employed as a stationary phase for preparing capillary GC column.There are 41 racemates include monohydric alcohols,diols,esters,lactones,halogenated hydrocarbons,ethers,epoxides,ketones,sulfoxides,etc.have obtained different degrees of resolution on the column,indicating the excellent chiral recognition ability of the column.By comparison,it was found that the chiral recognition ability of this column was complementary to those of ?-DEX 120 column,CC9 and CC10 based columns.Besides,positional isomers,n-alkanes,n-alcohols and aromatics can also be well separated on the column.(4)The [3+6] prismatic homochiral POC POC-3 was prepared by condensation reaction of 3,3',5,5'-tetraformyl-4,4'-biphenyldiol with(1R,2R)-1,2-cyclohexadidiamine,and it was used as stationary phase for GC separations.The column shows good separation performance not only for the separation of isomers,n-alkanes,n-alcohols and aromatic hydrocarbons,but also for the resolution of racemic compounds.It can resolve many racemates which cannot be resolved by?-DEX 120 column.