title: The single-molecule conductance and electrochemical electron-transfer rate are related by a power law.
abstract: This study examines quantitative correlations between molecular conductances and standard electrochemical rate constants for alkanes and peptide nucleic acid (PNA) oligomers as a function of the length, structure, and charge transport mechanism. The experimental data show a power-law relationship between conductances and charge transfer rates within a given class of molecules with the same bridge chemistry, and a lack of correlation when a more diverse group of molecules is compared, in contrast with some theoretical predictions. Surprisingly, the PNA duplexes exhibit the lowest charge-transfer rates and the highest molecular conductances. The nonlinear rate-conductance relationships for structures with the same bridging chemistries are attributed to differences in the charge-mediation characteristics of the molecular bridge, energy barrier shifts and electronic dephasing, in the two different experimental settings.
authors.affiliation: Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
authors.forename: Emil
authors.initials: E
authors.lastname: Wierzbinski
authors.forename: Ravindra
authors.initials: R
authors.lastname: Venkatramani
authors.forename: Kathryn L
authors.initials: KL
authors.lastname: Davis
authors.forename: Silvia
authors.initials: S
authors.lastname: Bezer
authors.forename: Jing
authors.initials: J
authors.lastname: Kong
authors.forename: Yangjun
authors.initials: Y
authors.lastname: Xing
authors.forename: Eric
authors.initials: E
authors.lastname: Borguet
authors.forename: Catalina
authors.initials: C
authors.lastname: Achim
authors.forename: David N
authors.initials: DN
authors.lastname: Beratan
authors.forename: David H
authors.initials: DH
authors.lastname: Waldeck
mesh_terms: D000473:Alkanes / Q000737:chemistry*; D004553:Electric Conductivity; D004563:Electrochemistry; D004579:Electron Transport; D007700:Kinetics; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D020135:Peptide Nucleic Acids / Q000737:chemistry*
chemical_list: D000473:Alkanes; D020135:Peptide Nucleic Acids