A chiral porous organic cage for molecular recognition using gas chromatography

Abstract

Molecular organic cages as shape-persistent organic molecules with permanent and accessible cavities have attracted a lot of interest because of their importance as host-guest systems. Herein, we report a chiral porous organic cage (POC) CC9 diluted with a polysiloxane OV-1701 to fabricate a CC9-coated capillary column, which was used for the high-resolution gas chromatographic separation of organic compounds, including positional isomers and racemates. On the CC9-coated capillary column, a large number of racemic compounds such as chiral alcohols, esters, ethers and epoxides can be resolved without derivatization. By comparing the chiral recognition ability of the CC9-coated column with the commercially available β-DEX 120 column and the POC CC3-R coated column recently reported by our group, the CC9-coated column offered good resolution during the separation of some racemates, that were not separated using the β-DEX 120 column or POC CC3-R coated column. Therefore, the CC9-coated column can be complementary to the β-DEX 120 column and CC3-R coated column. The results indicated that the CC9-coated column exhibited great potential for application in the separation of positional isomers and enantiomers with great selectivity, high resolution and good reproducibility.

Keywords: Capillary column; Chiral separation; Chiral stationary phase; Gas chromatography; Porous organic cage.