Porous Organic Nanocages CC3 and CC3–OH for Chiral Gas Chromatography

Porous organic nanocages (POCs) have received great concern in diverse areas recently. However, a long reaction time as well as a toxic catalyst or solvents are still used to synthesize POCs, which may limit their broad applications. In addition, the synthesis of modified POCs will largely promote and expand their applications. Here we report a rapid, green, and catalyst-free method to synthesize model nano-POC CC3R and modified CC3S to tune their selectivity and to expand their applications in chiral gas chromatographic (GC) separation of many challengeable chiral alcohols. The nanosized CC3R is successfully synthesized via an ethanolic refluxing method within 4 h without any toxic catalyst or inert gas protection. The prepared CC3R coated capillary column provides good resolution and selectivity to diverse chiral alcohols. The mirrored CC3S and hydroxyl-modified CC3R–OH are also designed and synthesized via the ethanolic refluxing method to tune their selectivity and resolution for chiral alcohols. The introduction of hydroxyl groups into CC3R–OH nanocages largely enhanced their hydrogen-bonding forces to chiral alcohols, leading to the improved resolution and selectivity for chiral alcohols, which revealed the promise of modified POCs in chiral separation. This work may promote the synthesis, modification, and chiral chromatographic application of POCs.