title: A molecular switch based on potential-induced changes of oxidation state.
abstract: We have measured the conductance of a hepta-aniline oligomer attached to gold electrodes held under potential control in electrolyte. It increases fifteen-fold (to 5.3+/-0.4 nS) on oxidation from the leucoemeraldine form to the emeraldine salt. The single-molecule current-voltage characteristic, linear in toluene, displays negative differential resistance in an acidic electrolyte. The negative differential resistance is accounted for by modification of the local surface potential by the applied bias. These results connect electrochemical data directly to molecular electronic behavior in a two-terminal device.
authors.affiliation: Department of Physics and Astronomy, Columbia University, NY, USA.
authors.forename: Fan
authors.initials: F
authors.lastname: Chen
authors.forename: Jin
authors.initials: J
authors.lastname: He
authors.forename: Colin
authors.initials: C
authors.lastname: Nuckolls
authors.forename: Tucker
authors.initials: T
authors.lastname: Roberts
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Klare
authors.forename: Stuart
authors.initials: S
authors.lastname: Lindsay
mesh_terms: D000814:Aniline Compounds / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects*; D039301:Computers, Molecular; D017097:Electric Impedance; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D004574:Electromagnetic Fields; D006046:Gold / Q000737:chemistry*; D008422:Materials Testing; D049329:Nanostructures / Q000032:analysis / Q000737:chemistry* / Q000528:radiation effects*; D010084:Oxidation-Reduction
chemical_list: D000814:Aniline Compounds; D006046:Gold