title: Synthetic molecular machine based on reversible end-to-interior and end-to-end loop formation triggered by electrochemical stimuli.
abstract: We have designed and synthesized a novel [2]pseudorotaxane-based molecular machine in which the interconversion between end-to-interior and end-to-end loop structures is reversibly controlled by electrochemical stimuli. Cucurbit[8]uril (CB[8]) and the thread molecule 3(4+) with an electron-rich hydroxynaphthalene unit and two electron-deficient viologen units form the 1:1 complex 4(4+) with an end-to-interior loop structure, which is reversibly converted into an end-to-end structure upon reduction. Large changes in shape and size of the molecule accompany the reversible redox process. The key feature of the machine-like behavior is the reversible interconversion between an intramolecular charge-transfer complex and viologen cation radical dimer inside CB[8] triggered by electrochemical stimuli.
authors.affiliation: National Creative Research Initiative Center for Smart Supramolecules and Department of Chemistry, Pohang University of Science and Technology, San 31 Hyojadong, Pohang 790-784, Korea.
authors.forename: Jae Wook
authors.initials: JW
authors.lastname: Lee
authors.forename: Ilha
authors.initials: I
authors.lastname: Hwang
authors.forename: Woo Sung
authors.initials: WS
authors.lastname: Jeon
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Ko
authors.forename: Shigeru
authors.initials: S
authors.lastname: Sakamoto
authors.forename: Kentaro
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Kimoon
authors.initials: K
authors.lastname: Kim
mesh_terms: D004563:Electrochemistry; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D013053:Spectrophotometry