title: Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F4TCNQ.
abstract: We describe the synthesis and single-molecule electrical transport properties of a molecular wire containing a π-extended tetrathiafulvalene (exTTF) group and its charge-transfer complex with F4TCNQ. We form single-molecule junctions using the in situ break junction technique using a homebuilt scanning tunneling microscope with a range of conductance between 10 G0 down to 10(-7) G0. Within this range we do not observe a clear conductance signature of the neutral parent molecule, suggesting either that its conductance is too low or that it does not form a stable junction. Conversely, we do find a clear conductance signature in the experiments carried out on the charge-transfer complex. Due to the fact we expected this species to have a higher conductance than the neutral molecule, we believe this supports the idea that the conductance of the neutral molecule is very low, below our measurement sensitivity. This idea is further supported by theoretical calculations. To the best of our knowledge, these are the first reported single-molecule conductance measurements on a molecular charge-transfer species.
authors.affiliation: Departamento de Química Orgánica, Facultad de Química, Universidad Complutense, E-28040 Madrid, Spain.
authors.forename: Raúl
authors.initials: R
authors.lastname: García
authors.affiliation: Departamento de Química Orgánica, Facultad de Química, Universidad Complutense, E-28040 Madrid, Spain.
authors.forename: M Ángeles
authors.initials: MÁ
authors.lastname: Herranz
authors.affiliation: Fundación IMDEA Nanoscience, Campus de Cantoblanco, Universidad Autónoma, E-28048 Madrid, Spain.
authors.forename: Edmund
authors.initials: E
authors.lastname: Leary
authors.affiliation: Fundación IMDEA Nanoscience, Campus de Cantoblanco, Universidad Autónoma, E-28048 Madrid, Spain.
authors.forename: M Teresa
authors.initials: MT
authors.lastname: González
authors.affiliation: Departamento de Física de la Materia Condensada, and Instituto "Nicolás Cabrera", Universidad Autonoma de Madrid, E-28049 Madrid, Spain.
authors.forename: Gabino Rubio
authors.initials: GR
authors.lastname: Bollinger
authors.affiliation: Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Marius
authors.initials: M
authors.lastname: Bürkle
authors.affiliation: Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, Spain.
authors.forename: Linda A
authors.initials: LA
authors.lastname: Zotti
authors.affiliation: Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Asai
authors.affiliation: Department of Physics, University of Konstanz, D-78457 Konstanz, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Pauly
authors.affiliation: Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Cuevas
authors.affiliation: Fundación IMDEA Nanoscience, Campus de Cantoblanco, Universidad Autónoma, E-28048 Madrid, Spain ; Departamento de Física de la Materia Condensada, and Instituto "Nicolás Cabrera", Universidad Autonoma de Madrid, E-28049 Madrid, Spain.
authors.forename: Nicolás
authors.initials: N
authors.lastname: Agraït
authors.affiliation: Departamento de Química Orgánica, Facultad de Química, Universidad Complutense, E-28040 Madrid, Spain ; Fundación IMDEA Nanoscience, Campus de Cantoblanco, Universidad Autónoma, E-28048 Madrid, Spain.
authors.forename: Nazario
authors.initials: N
authors.lastname: Martín
keywords: DFT-based transport; break junction measurements; charge-transfer complex; molecular electronics; tetrathiafulvalene