Separation of 2-Bromobutane, 2-Chlorobutane, 2-Chloropentane, and 2-Butanol Enantiomers Using a Stationary Phase Based on a Supramolecular Uracil Structure

Abstract

We proposed a new chiral stationary phase based on a supramolecular uracil structure with induced chirality. According to the Kondepudi effect, mechanical stirring leads to the formation of a supramolecular structure layer on the surface of an adsorbent with a predominance of one of types of chiral supramolecular clusters. The obtained stationary phase was used for the gas-chromatographic separation of enantiomers of 2-bromobutane, 2-chlorobutane, 2-chloropentane, and 2-butanol. The effectiveness of a 1-m column packed with an inert stationary phase modified with uracil is 200–400 theoretical plates. The enantiomers of 2-bromobutane and 2-chlorobutane were completely separated using the proposed stationary phase in 210 and 180 s, respectively, at 45°C. The enantiomers of 2-chloropentane were separated at 60 and 65°C in 170 and 160 s, respectively. The enantiomers of 2-butanol were partially separated at 100°C. The enantioselectivity of the proposed stationary phase is probably associated with the adsorption of one enantiomer outside the cavity of the supramolecular structure and the other enantiomer inside it.