Herrer, I.L. and Ismael, A.K. and Milán, D.C. and Vezzoli, A. and Martín, S. and González-Orive, A. and Grace, I. and Lambert, C. and Serrano, J.L. and Nichols, R.J. and Cea, P. (2018) Unconventional Single-Molecule Conductance Behavior for a New Heterocyclic Anchoring Group: Pyrazolyl. Journal of Physical Chemistry Letters, 9 (18). pp. 5364-5372. ISSN 1948-7185
Full text not available from this repository.Abstract
Electrical conductance across a molecular junction is strongly determined by the anchoring group of the molecule. Here we highlight the unusual behavior of 1,4-bis(1H-pyrazol-4-ylethynyl)benzene that exhibits unconventional junction current versus junction-stretching distance curves, which are peak-shaped and feature two conducting states of 2.3 × 10-4 G0 and 3.4 × 10-4 G0. A combination of theory and experiments is used to understand the conductance of single-molecule junctions featuring this new anchoring group, i.e., pyrazolyl. These results demonstrate that the pyrazolyl moiety changes its protonation state and contact binding during junction evolution and that it also binds in either end-on or facial geometries with gold contacts. The pyrazolyl moiety holds general interest as a contacting group, because this linkage leads to a strong double anchoring of the molecule to the gold electrode, resulting in enhanced conductance values. Copyright © 2018 American Chemical Society.