title: Structure-property relationships in redox-gated single molecule junctions--a comparison of pyrrolo-tetrathiafulvalene and viologen redox groups.
abstract: We demonstrate that the electrical "switching" behavior of single molecules connected between two electrode contacts can be controlled by altering their structure and electrochemical characteristics. The electrical properties of gold|molecule|gold single molecule junctions incorporating HS(CH2)6-X-(CH2)6SH, where X = viologen (4,4'-bipyridinium) or pyrrolotetrathiafulvalene, are determined using a scanning tunneling microscopy based technique. The switching behavior, controlled through a tuneable electrochemical gate, changes from an on-off response (viologen) to an off-on-off response (pyrrolotetrathiafulvalene) on changing the central redox group. In contrast, the electrical properties of junctions incorporating redox-inactive HS(CH2)6-1,4-C6H4-(CH2)6SH do not alter significantly as a function of applied potential.
authors: Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, UK.
authors: Edmund
authors: E
authors: Leary
authors: Simon J
authors: SJ
authors: Higgins
authors: Harm
authors: H
authors: van Zalinge
authors: Wolfgang
authors: W
authors: Haiss
authors: Richard J
authors: RJ
authors: Nichols
authors: Sune
authors: S
authors: Nygaard
authors: Jan Oskar
authors: JO
authors: Jeppesen
authors: Jens
authors: J
authors: Ulstrup