Subcomponent self-assembly construction of tetrahedral cage Fe^II₄L₄ for high-resolution gas chromatographic...

Metal organic cages (MOCs), as an emerging discrete supramolecular compounds, have received widespread attention in separation, biomedicine, gas capture, catalysis, and molecular recognition due to their porosity, adjustability and stability. Herein, we present a new chiral MOC Fe^II₄L₄ coated capillary column prepared for gas chromatographic (GC) separation of different types of organic compounds, including n-alkanes, n-alcohols, alkylbenzenes, isomers, especially for racemic compounds. There are 20 different kinds of racemates (e.g., alcohols, ethers, epoxides, esters, alkenes, and aldehydes) were well resolved on the Fe^II₄L₄ chiral column and a maximum resolution value for 1-phenyl-1-propanol reaches 6.17. The Fe^II₄L₄ coated column exhibited high column efficiency (3100 plates m^-1 for n-dodecane) and good enantiomeric resolution complementary to that of a commercial β-DEX 120 column and the previously reported chiral MOC [Fe₄L₆] (ClO₄)₈ coated column. The relative standard deviation (RSDs) of the peak area and retention time of glycidol and nitrotoluene were below 1.2 %. This study reveals that chiral MOCs have good application prospects in chromatographic separation.