Tuning Conductance in π-σ-π Single-Molecule Wires.
While the single-molecule conductance properties of π-conjugated and σ-conjugated systems have been well-studied, little is known regarding the conductance properties of mixed σ-π backbone wires and the factors that control their transport properties. Here we utilize a scanning tunneling microscope-...
| Publicado en: | Journal of the American Chemical Society Vol. 138; no. 24; pp. 7791 - 7796 |
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| Autores principales: | , , , , , , , |
| Formato: | Artículo |
| Publicado: |
American Chemical Society
6/22/2016
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| Materias: | |
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=116707336&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 116707336 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 6/22/2016 vid: 138 iid: 24 pid: 997 pub: American Chemical Society artinfo: ui: 116707336 10.1021/jacs.6b04394 ppf: 7791 ppct: 5 formats: tig: atl: Tuning Conductance in π-σ-π Single-Molecule Wires. aug: au: Su, Timothy A. Li, Haixing Klausen, Rebekka S. Widawsky, Jonathan R. Batra, Arunabh Steigerwald, Michael L. Venkataraman, Latha Nuckolls, Colin affil: Department of Chemistry, Columbia University, New York, New York 10027, United States Department of Physics and Applied Math, Columbia University, New York, New York 10027, United States su: Single molecules Density functionals Atomic radius Electric admittance Organic compounds Electronegativity sug: subj: Single molecules Density functionals Atomic radius Electric admittance Organic compounds Electronegativity ab: While the single-molecule conductance properties of π-conjugated and σ-conjugated systems have been well-studied, little is known regarding the conductance properties of mixed σ-π backbone wires and the factors that control their transport properties. Here we utilize a scanning tunneling microscope-based break-junction technique to study a series of molecular wires with π-σ-π backbone structures, where the π-moiety is an electrode-binding thioanisole ring and the σ-moiety is a triatomic α-β-α chain composed of C, Si, or Ge atoms. We find that the sequence and composition of group 14 atoms in the α-β-α chain dictates whether electronic communication between the aryl rings is enhanced or suppressed. Placing heavy atoms at the α-position decreases conductance, whereas placing them at the β-position increases conductance: for example, the C-Ge-C sequence is over 20 times more conductive than the Ge-C-Ge sequence. Density functional theory calculations reveal that these conductance trends arise from periodic trends (i.e., atomic size, polarizability, and electronegativity) that differ from C to Si to Ge. The periodic trends that control molecular conductance here are the same ones that give rise to the α and β silicon effects from physical organic chemistry. These findings outline a new molecular design concept for tuning conductance in single-molecule electrical devices. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2016 holdings: @attributes: islocal: N |
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