title: Charge transport in C60-based dumbbell-type molecules: mechanically induced switching between two distinct conductance states.
abstract: Single molecule charge transport characteristics of buckminsterfullerene-capped symmetric fluorene-based dumbbell-type compound 1 were investigated by scanning tunneling microscopy break junction (STM-BJ), current sensing atomic force microscopy break junction (CS-AFM-BJ), and mechanically controlled break junction (MCBJ) techniques, under ambient conditions. We also show that compound 1 is able to form highly organized defect-free surface adlayers, allowing the molecules on the surface to be addressed specifically. Two distinct single molecule conductance states (called high G(H)(1) and low G(L)(1)) were observed, depending on the pressure exerted by the probe on the junction, thus allowing molecule 1 to function as a mechanically driven molecular switch. These two distinct conductance states were attributed to the electron tunneling through the buckminsterfullerene anchoring group and fully extended molecule 1, respectively. The assignment of conductance features to these configurations was further confirmed by control experiments with asymmetrically designed buckminsterfullerene derivative 2 as well as pristine buckminsterfullerene 3, both lacking the G(L) feature.
authors: Department of Chemistry and Biochemistry, University of Bern , Freiestrasse 3, CH-3012 Bern, Switzerland.
authors: Pavel
authors: P
authors: Moreno-García
authors: Andrea
authors: A
authors: La Rosa
authors: Viliam
authors: V
authors: Kolivoška
authors: Daniel
authors: D
authors: Bermejo
authors: Wenjing
authors: W
authors: Hong
authors: Koji
authors: K
authors: Yoshida
authors: Masoud
authors: M
authors: Baghernejad
authors: Salvatore
authors: S
authors: Filippone
authors: Peter
authors: P
authors: Broekmann
authors: Thomas
authors: T
authors: Wandlowski
authors: Nazario
authors: N
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