Abstract
Electron injection is demonstrated to trigger electrocatalytic chain reactions capable of releasing a solvent molecule and forming a redox active guest molecule. One-electron reduction of a hydroxy anthrone derivative (AQH-CH(2)CN) results in the formation of an anthraquinone radical anion (AQ˙(-)) and acetonitrile (CH(3)CN). The resulting fragment of AQ˙(-) exhibits high stability under mild reducing conditions, and it has enough reducing power to reduce the reactant of AQH-CH(2)CN. Hence, subsequent electron transfer from AQ˙(-) to AQH-CH(2)CN yields the secondary AQ˙(-) and CH(3)CN, while the initial AQ˙(-) is subsequently oxidized to AQ. Overall, the reactants of AQH-CH(2)CN are completely converted into AQ and CH(3)CN in sustainable electrocatalytic chain reactions. These electrocatalytic chain reactions are mild and sustainable, successfully achieving catalytic electron-triggered charge-transfer (CT) complex formation. Reactant AQH-CH(2)CN is non-planar, making it unsuitable for CT interaction with an electron donor host compound (U(H)Ant(2)) bearing parallel anthracene tweezers. However, conversion of AQH-CH(2)CN to planar electron acceptor AQ by the electrocatalytic chain reactions turns on CT interaction, generating a host CT complex with U(H)Ant(2) (AQ ⊂ U(H)Ant(2)). Therefore, sustainable electrocatalytic chain reactions can control CT interactions using only a catalytic amount of electrons, ultimately affording a one-electron switch associated with catalytic electron-triggered turn-on molecular recognition.