A homochiral metal-organic polyhedron CMOP-IL for capillary gas chromatographic separation

Chiral metal-organic polyhedra (CMOPs) have come to be recognized as ideal materials for chromatographic enantioseparation owing to their unique molecular recognition ability. Herein, the utilization of a novel chiral stationary phase (CSP) based on CMOP-IL ([Cu₁₂(L_IL)₁₂(H₂O)₁₂], IL = L-isoleucine) for gas chromatographic separation was explored. A variety of mixtures (n-alkanes, n-alcohols and alkylbenzenes) and multiple isomers were effectively separated on the CMOP-IL capillary column. The separation performance of the CMOP-IL column for most mixtures and isomers is superior to that of the previously reported MOP-V ([Cu₁₂(L_V)₁₂(H₂O)₁₂], V = L-valine) column. Notably, the CMOP-IL capillary column exhibited excellent enantioselectivity towards various racemates that include alcohols, ethers, aldehydes, epoxides, and amino acid derivatives. In comparison with the commercial β-DEX 120 column, MOP-V column, and Co-L-GG column, the complementary chiral resolving capabilities of the MOP capillary column were demonstrated in separating racemates. Additionally, the relative standard deviation (RSD) values of retention time and peak area of allyl glycidyl ether and o,m,p-nitrotoluene stayed within a range below 1 %, indicating good repeatability and stability of the MOP column in gas chromatographic separation. The study indicates that CMOP based on l-isoleucine, as a novel CSP, holds promising applications in gas chromatography.