Electrochemically Induced Molecular Motions in Pseudorotaxanes: A Case of Dual-Mode (Oxidative and Reductive) Dethreading

The electrochemical and spectroscopic properties of a pseudorotaxane formed in acetonitrile solution by self‐assembly of a wire‐type electron donor based on the tetrathiafulvalene unit and the cyclobis(paraquat‐p‐phenylene) tetracationic electron acceptor have been investigated. We show that a) reversible dethreading/rethreading cycles of the pseudorotaxane can be performed by either oxidation and successive reduction of the electron‐donor wire or reduction and successive oxidation of the electron‐accepting tetracationic cyclophane, and b) because of this special behavior, the input (electrochemical)/output (absorption spectrum) characteristics of this molecular‐level system correspond to those of an XNOR logic gate. Reversible dethreading/rethreading cycles of a pseudorotaxane can be produced either by oxidation and subsequent reduction of the electron‐donor “wire”, or by reduction and subsequent oxidation of the electron‐accepting tetracationic cyclophane in the system depicted schematically on the right. Because of this special behavior, the input (electrochemical)/output (absorption spectrum) characteristics of this molecular‐level system correspond to those of an XNOR logic gate.