Highly Improved Chiral-Selective Resolution in Pillar[5]arene-Functionalized Molecularly Imprinted Membranes

Abstract

It is a challenging task to achieve the effective separation of chiral compounds under simple and rapid conditions. In order to solve this problem, this study used the molecularly imprinted membrane (MIM) technology developed on the basis of biological semi-permeable membranes, using S-triadimefon as the template molecule, and successfully prepared MIMs by photo-initiated polymerization. By adding macrocyclic molecular 1,4-bis(allyloxy)pillar[5]arene as a functional monomers, the effectiveness of the chiral recognition sites of the target molecules is improved, thereby improving the chiral selectivity of the MIM and optimizing the molar ratio of template molecules, monomers, and cross-linkers. On this basis, the separation effect of non-MIM (NIM), single-monomer MIM (MIM-I), and two-monomer MIM (MIM-II) on triadimefon enantiomers was investigated. It was found that the enantiomer excess (e. e.) % value of MIM-I is larger than that of NIM, but the value of MIM-I is still very low. When pillar[5]arene, a macrocyclic molecule was added as the second monomer, its e. e. % increased from 27.4 to 84.8%.