title: Frustrated rotations in single-molecule junctions.
abstract: We compare the conductance of 1,4-bis(methylthio)benzene with that of 2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b']dithiophene and the conductance of 1,4-bis(methylseleno)benzene with that of 2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b']diselenophene and show explicitly that the orientation of an Au-S or Au-Se bond relative to the aromatic pi system controls electron transport through conjugated molecules. Specifically, we have found that the conduction pathway connects the Au electrodes to the aromatic pi-system via the chalcogen p lone pairs, and greater overlaps among these components lead to higher conductivity through the molecular junction.
authors.affiliation: Department of Chemistry, Columbia University, New York, New York, USA.
authors.forename: Young S
authors.initials: YS
authors.lastname: Park
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Widawsky
authors.forename: Maria
authors.initials: M
authors.lastname: Kamenetska
authors.forename: Michael L
authors.initials: ML
authors.lastname: Steigerwald
authors.forename: Mark S
authors.initials: MS
authors.lastname: Hybertsen
authors.forename: Colin
authors.initials: C
authors.lastname: Nuckolls
authors.forename: Latha
authors.initials: L
authors.lastname: Venkataraman