Wireless electrochemical actuation of soft materials towards chiral stimuli

Unconventional approaches for chiral resolution

Chirality is a fundamental and ubiquitous property of nature involved in multiple fields of science. In particular, the possible resolution of the enantiomeric forms of a molecule is crucial in the pharmaceutical, food, and agrochemical industries. The search for efficient, broad-spectrum, and yet simple methods for obtaining enantiomerically pure substances is a current challenge. Enantioselective resolution methods rely on an asymmetric environment that allows the two antipodes of a chiral molecule to be distinguished. In addition to enantiomeric separation techniques, such as chromatography and electrophoresis, new promising approaches involving out-of-the-scheme synergistic effects between chiral selectors (CS) and external stimuli are emerging. This Trends article discusses different enantioselective mechanisms triggered by unconventional physicochemical stimuli for the design of avant-garde approaches that could offer novel perspectives in the field of chiral resolution.

Wireless Hollow Miniaturized Objects for Electroassisted Chiral Resolution

Chiral resolution plays a crucial role in the field of drug development, especially for a better understanding of biochemical processes. In such a context, classic separation methods have been used for decades due to their versatility and easy scale-up. Among the many attempts proposed for enantioselective separation, electroassisted methods are presented as an interesting alternative. Herein, we present the use of wirelessly activated hollow tubular systems for the effective, simple, and tunable separation of racemic and enantioenriched mixtures. These double-layered tubular objects consist of an external polypyrrole chassis, a polymer with good electromechanical properties, functionalized in its inner part with an inherently chiral oligomer. The synergy between the electromechanical pumping process of the outer layer and the enantioselective affinity of the inner part induces the system to behave as a miniaturized chiral column. These hybrid objects are able to separate racemic and enantioenriched solutions of chiral model analytes into the corresponding enantiomers in high enantiomeric purity. Finally, these electromechanical systems can resolve mixtures formed by chiral probes with completely uncorrelated molecular structures injected simultaneously into the single antipodes.