Electrochemical Bromide Sensing with a Halogen Bonding [2]Rotaxane

Abstract

The selective electrochemical sensing of heavy halides, such as bromide, over more charge‐dense counterparts, like chloride, using mechanically‐interlocked structures remains a formidable challenge. Using the active‐metal templation methodology, the first redox‐active ferrocene‐appended rotaxane containing an all‐halogen bonding anion binding cavity was synthesised. 1H NMR binding studies in aqueous–organic solvent media demonstrated a marked recognition bias for heavy halides, facilitating the selective redox sensing of bromide over chloride to be demonstrated for the very first time with an interlocked host molecule.