title: Nature of electron transport by pyridine-based tripodal anchors: potential for robust and conductive single-molecule junctions with gold electrodes.
abstract: We have designed and synthesized a pyridine-based tripodal anchor unit to construct a single-molecule junction with a gold electrode. The advantage of tripodal anchoring to a gold surface was unambiguously demonstrated by cyclic voltammetry measurements. X-ray photoelectron spectroscopy measurements indicated that the π orbital of pyridine contributes to the physical adsorption of the tripodal anchor unit to the gold surface. The conductance of a single-molecule junction that consists of the tripodal anchor and diphenyl acetylene was measured by modified scanning tunneling microscope techniques and successfully determined to be 5 ± 1 × 10(-4)G(0). Finally, by analyzing the transport mechanism based on ab initio calculations, the participation of the π orbital of the anchor moieties was predicted. The tripodal structure is expected to form a robust junction, and pyridine is predicted to achieve π-channel electric transport.
authors.affiliation: The Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1, Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ie
authors.forename: Tomoya
authors.initials: T
authors.lastname: Hirose
authors.forename: Hisao
authors.initials: H
authors.lastname: Nakamura
authors.forename: Manabu
authors.initials: M
authors.lastname: Kiguchi
authors.forename: Noriaki
authors.initials: N
authors.lastname: Takagi
authors.forename: Maki
authors.initials: M
authors.lastname: Kawai
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Aso