A chiral metal–organic polyhedron used as stationary phase for gas chromatographic separations

Abstract

Metal-organic polyhedra (MOPs), as a novel class of porous materials, exhibit distinctive application potential in molecular recognition, separation, catalysis, luminescent materials, drug delivery, and biomedicine owing to their tunable geometric shape and size, well-defined cavities, and discrete characteristics. In this study, we report that a chiral MOP [Cu12(LV)12(H2O)12] (V = L-valine) coated capillary column was used for gas chromatographic separations. The MOP coated capillary column offered the efficient separation of n-alkanes, alkylbenzenes, n-alcohols, multiple types of isomers, and enantiomers with high selectivity. Various enantiomers including esters, halogenated hydrocarbons, alcohols, ethers, aldehydes, and amino acid derivatives were well resolved on this chiral column, especially for some amino acid derivatives (e.g., Rs = 5.24 for tyrosine derivative). Compared with the commercial β-DEX 120 column for separation of the tested racemates, the chiral resolution performance of the MOP coated column can be complementary to that of β-DEX 120 column. Using 1,2-dichloropropane and o, m, p-dichlorobenzene as analytes, the MOP coated column exhibited good stability and reproducibility for gas chromatographic separations. The relative standard deviations (RSDs) of the retention time and peak area for repeated separation of 1, 2-dichloropropane and o, m, p-dichlorobenzene were less than 1.15 and 0.79 %, respectively. The results show that the chiral MOP holds great potential as a novel type of CSP for application in gas chromatography.