title: Toward Multiple Conductance Pathways with Heterocycle-Based Oligo(phenyleneethynylene) Derivatives.
abstract: In this paper, we have systematically studied how the replacement of a benzene ring by a heterocyclic compound in oligo(phenyleneethynylene) (OPE) derivatives affects the conductance of a molecular wire using the scanning tunneling microscope-based break junction technique. We describe for the first time how OPE derivatives with a central pyrimidine ring can efficiently link to the gold electrode by two pathways presenting two different conductance G values. We have demonstrated that this effect is associated with the presence of two efficient conductive pathways of different length: the conventional end-to-end configuration, and another with one of the electrodes linked directly to the central ring. This represents one of the few examples in which two defined conductive states can be set up in a single molecule without the aid of an external stimulus. Moreover, we have observed that the conductance through the full length of the heterocycle-based OPEs is basically unaffected by the presence of the heterocycle. All these results and the simplicity of the proposed molecules push forward the development of compounds with multiple conductance pathways, which would be a breakthrough in the field of molecular electronics.
authors.affiliation: Departamento de Química Orgánica, Universidad de Granada , C. U. Fuentenueva, Avda. Severo Ochoa s/n, E-18071 Granada, Spain.
authors.forename: Delia
authors.initials: D
authors.lastname: Miguel
authors.affiliation: Departamento de Química Orgánica, Universidad de Granada , C. U. Fuentenueva, Avda. Severo Ochoa s/n, E-18071 Granada, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Álvarez de Cienfuegos
authors.affiliation: Fundación IMDEA Nanociencia, Ciudad Universitaria de Cantoblanco , E-28049 Madrid, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Martín-Lasanta
authors.affiliation: Departamento de Química Orgánica, Universidad de Granada , C. U. Fuentenueva, Avda. Severo Ochoa s/n, E-18071 Granada, Spain.
authors.forename: Sara P
authors.initials: SP
authors.lastname: Morcillo
authors.affiliation: Departamento of Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco , E-28049 Madrid, Spain.
authors.forename: Linda A
authors.initials: LA
authors.lastname: Zotti
authors.affiliation: Fundación IMDEA Nanociencia, Ciudad Universitaria de Cantoblanco , E-28049 Madrid, Spain.
authors.forename: Edmund
authors.initials: E
authors.lastname: Leary
authors.affiliation: Nanomaterials 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: Nanomaterials 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: Departamento de Química Orgánica, Universidad de Granada , C. U. Fuentenueva, Avda. Severo Ochoa s/n, E-18071 Granada, Spain.
authors.forename: Rocío
authors.initials: R
authors.lastname: Jurado
authors.affiliation: Departamento de Química Orgánica, Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco , E-28049 Madrid, Spain.
authors.forename: Diego J
authors.initials: DJ
authors.lastname: Cárdenas
authors.affiliation: Departamento de Física de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid , E-28049 Madrid, Spain.|Instituto "Nicolás Cabrera", Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco , E-28049 Madrid, Spain.
authors.forename: Gabino
authors.initials: G
authors.lastname: Rubio-Bollinger
authors.affiliation: Fundación IMDEA Nanociencia, Ciudad Universitaria de Cantoblanco , E-28049 Madrid, Spain.|Departamento de Física de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid , E-28049 Madrid, Spain.|Instituto "Nicolás Cabrera", Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco , E-28049 Madrid, Spain.
authors.forename: Nicolás
authors.initials: N
authors.lastname: Agraït
authors.affiliation: Departamento de Química Orgánica, Universidad de Granada , C. U. Fuentenueva, Avda. Severo Ochoa s/n, E-18071 Granada, Spain.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Cuerva
authors.affiliation: Fundación IMDEA Nanociencia, Ciudad Universitaria de Cantoblanco , E-28049 Madrid, Spain.
authors.forename: M Teresa
authors.initials: MT
authors.lastname: González