Work

Tuning Supramolecular Selectivity for Hydrosulfide: Linear Free Energy Relationships Reveal Preferential C–H Hydrogen Bond Interactions

Year: 2020

Type: article

Abstract: Supramolecular anion receptors can be used to study the molecular recognition properties of the reactive yet biologically critical hydrochalcogenide anions (HCh – ). Achieving selectivity for HCh – over the halides is challenging but necessary for not only developing future supramolecular probes for HCh – binding and detection, but also for understanding the fundamental properties that govern these binding and recognition events. Here we demonstrate that linear free energy relationships (LFERs)—including Hammett and Swain–Lupton plots—reveal a clear difference in sensitivity to the polarity of an aryl C–H hydrogen bond (HB) donor for HS – over other HCh – and halides. Analysis using electrostatic potential maps highlights that this difference in sensitivity results from a preference of the aryl C–H HB donor for HS – in this host scaffold. From this study, we demonstrate that LFERs are a powerful tool to gain interpretative insight into motif design for future anion-selective supramolecular receptors and highlight the importance of C–H HB donors for HS – recognition. From our results, we suggest that aryl C–H HB donors should be investigated in the next generation of HS – selective receptors based on the enhanced HS – selectivity over other competing anions in this system.

Source: Journal of the American Chemical Society

DOI: 10.1021/jacs.0c00441