title: Probing the conformation of physisorbed molecules at the atomic scale using STM manipulation.
abstract: We use scanning tunneling microscope (STM) manipulation and density functional theory calculation to investigate the structural properties of individual sexiphenyl molecules physisorbed on a Ag(111) surface at 6 K. The molecule-surface atomic registry is precisely determined by using atomic markers and a sexiphenyl functionalized tip. The calculations confirm the alternating twist of the sexiphenyl pi-rings on Ag(111). The pi-ring torsional angle, 11.4 degrees, is directly determined from the geometry of STM manipulation. This innovative experiment opens up a novel application of STM manipulation to probe the properties of "physisorbed" species on surfaces at the atomic level.
authors.affiliation: Nanoscale and Quantum Phenomena Institute, Physics and Astronomy Department, Ohio University, Athens, Ohio 45701, USA.
authors.forename: Kai-Felix
authors.initials: KF
authors.lastname: Braun
authors.forename: Saw-Wai
authors.initials: SW
authors.lastname: Hla