title: Control of molecular rotors by selection of anchoring sites.
abstract: We demonstrate a new method to switch on and off the rotational motion of a long-chain molecule by controlling the bonding geometry between the molecule and a substrate. An azobenzene derivative molecule adsorbed on a Au(111) surface is immobile only when its three rotation centers, comprised of two phenyl rings and a nitrogen-nitrogen bond, are located at hollow sites of the Au(111) surface, as observed by scanning tunneling microscopy. Rotational motion can be activated by exciting the vibrational modes and inducing hopping motion away from the immobile site with a voltage pulse.
authors.affiliation: Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea.
authors.forename: Hyo Won
authors.initials: HW
authors.lastname: Kim
authors.forename: M
authors.initials: M
authors.lastname: Han
authors.forename: H-J
authors.initials: HJ
authors.lastname: Shin
authors.forename: S
authors.initials: S
authors.lastname: Lim
authors.forename: Y
authors.initials: Y
authors.lastname: Oh
authors.forename: K
authors.initials: K
authors.lastname: Tamada
authors.forename: M
authors.initials: M
authors.lastname: Hara
authors.forename: Y
authors.initials: Y
authors.lastname: Kim
authors.forename: M
authors.initials: M
authors.lastname: Kawai
authors.forename: Young
authors.initials: Y
authors.lastname: Kuk