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Title: Bianthrone at a metal surface: Conductance switching with a bistable molecule made feasible by image charge effects

Bianthrone is a sterically hindered compound that exists in the form of two non-planar isomers. Our experimental study of single-molecule junctions with bianthrone reveals persistent switching of electric conductance at low temperatures, which can be reasonably associated to molecular isomerization events. Temperature dependence of the switching rate allows for an estimate of the activation energy of the process, on the order of 35–90 meV. Quantum-chemical calculations of the potential surface of neutral bianthrone and its anion, including identification of transition states, yields the isolated molecule isomerization barriers too high vs. the previous estimate, though in perfect agreement with previous experimental studies in solution. Nevertheless, we show that the attraction of the anion in the vicinity of the metal surface by its image charge can significantly alter the energetic landscape, in particular, by reducing the barrier to the values compatible with the observed switching behavior.
Authors:
; ;  [1] ; ; ;  [2] ;  [3]
  1. Université de Mons, Service de Chimie des Matériaux Nouveaux, Place du Parc 20, B-7000 Mons (Belgium)
  2. Department of Microtechnology and Nanoscience, Chalmers University of Technology, Kemivägen 9, S-41296 Göteborg (Sweden)
  3. Nano-Science Center and Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen (Denmark)
Publication Date:
OSTI Identifier:
22390927
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1642; Journal Issue: 1; Conference: ICCMSE-2010: International Conference of Computational Methods in Sciences and Engineering 2010, Kos (Greece), 3-8 Oct 2010; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ACTIVATION ENERGY; ANIONS; ELECTRIC CONDUCTIVITY; ELECTRIC CONTACTS; IMAGES; ISOMERIZATION; MATHEMATICAL SOLUTIONS; METALS; MOLECULES; POTENTIALS; QUANTUM MECHANICS; SURFACES; TEMPERATURE DEPENDENCE