Redox Controlled Chalcogen Bonding for Switchable Anion Recognition and Sensing



Inspired by the success of its related sigma-hole congener halogen bonding (XB), chalcogen bonding (ChB) is emerging as a powerful non-covalent interaction with a plethora of applications in supramolecular chemistry and beyond. In spite of its increasing importance, the judicious modulation of ChB donor strength remains a formidable challenge. Herein, we present, for the first time, the reversible and large-scale modulation of ChB potency by electrochemical redox control. This is exemplified by both the switching-ON of anion recognition via ChB oxidative activation of a novel bis(ferrocenyltellurotriazole) anion host and switching-OFF reductive ChB deactivation of anion binding potency with a telluroviologen receptor. The direct linking of the redox-active centre and ChB receptor donor sites enables strong coupling, which is reflected by up to a remarkable 3 orders of magnitude modulation of anion binding strength. This is demonstrated through large voltammetric perturbations of the respective receptor ferrocene and viologen redox couples, enabling, for the first time, ChB-mediated electrochemical anion sensing. The sensors not only display significant anion-binding induced electrochemical responses in competitive aqueous-organic solvent systems but can compete with, or even outperform similar, highly potent XB and HB sensors. These observations serve to highlight a unique (redox) tuneability of ChB and pave the way for further exploration of the reversible (redox) modulation of ChB in a wide range of applications including anion sensors as well as molecular switches and machines.


Supplementary material

Supporting Information - Redox Controlled Chalcogen Bonding for Switchable Anion Recognition and Sensing
Supporting Information for "Redox Controlled Chalcogen Bonding for Switchable Anion Recognition and Sensing" containing experimental details and additional data and discussions.