A dual chiral porous organic polymer synthesized by thiol-yne click chemistry strategy for capillary gas chromatography separations

Abstract

Porous Organic Polymers (POPs) have garnered increasing research interest due to their potential to integrate the characteristics of porous materials and polymers. The thiol-yne reaction, a novel “click” reaction confirmed in recent years, is characterized by its simplicity, efficiency, and versatility. There has been no reports on the introduction of dual chiral POP via click chemistry as chromatographic stationary phase.

This study employed a thiol-yne click chemistry approach to synthesize a dual chiral porous organic polymer (DC-POP) and successfully prepared the DC-POP-coated capillary column. The enantioselectivity of the novel chiral stationary phase (CSP) was investigated. The results demonstrated that the DC-POP possesses excellent separation performance, capable of resolving various racemic mixtures, including amino acid derivatives, chiral alcohols, ketones, esters, epoxides, and organic acids. The column exhibited good separation capabilities for multiple amino acid derivatives (e.g., Rs = 2.99 for arginine) and the number of theoretical plates was determined to be 3448 plates/m. Interestingly, this column was able to separate racemic mixtures that commercial columns could not, complementing the chiral resolution capabilities of both commercial β-DEX 120 columns and porous organic cage-coated capillary columns. Additionally, the impact of injection frequency on separation performance was evaluated. After multiple injections, the column showed good stability and repeatability, with relative standard deviations (n = 5) for retention time and resolution less than 0.7 % and 6.5 %, respectively. Further investigation was carried out into the effects of temperature on the separation by DC-POP-coated capillary column.

This study indicates that the first synthesis of DC-POP via thiol-yne click chemistry, showing its potential as a novel CSP for chiral selector in high-resolution GC enantioseparation.