Chiral metal-organic cage core-shell composite UMOP-S-2- Ppa@SiO2 used as stationary phase for HPLC enantioseparation

A facile one-pot strategy was developed to construct a core-shell UMOP-S-2-Ppa@SiO₂ composite using (S)-2-phenylpropionic acid as chiral selector. The prepared UMOP-S-2-Ppa@SiO₂ composite was utilized as a novel chiral stationary phase (CSP) for HPLC enantioseparation. Under normal-phase HPLC conditions, the packed column afforded effective enantioseparation for 18 racemates including alcohols, aldehydes, esters, ketones, amines, and epoxy compounds, among which 11 pairs of enantiomers achieved baseline resolution. Compared with the widely used Chiralpak AD-H and Chiralcel OD-H columns, the developed chiral column exhibited good chiral separation complementarity. It can efficiently resolve some racemates that fail to be separated by the above commercial columns. The column also demonstrated satisfactory repeatability and stability, and the relative standard deviations of retention time and peak area remained below 1.0% after 250 consecutive injections. These results demonstrate that chiral metal-organic cages(MOC)@SiO₂ core-shell composites prepared via a post-synthetic modification strategy hold great promise for HPLC enantioseparation, offering new insights into the development of MOC-based materials for chromatographic applications.