Single-Molecule Junctions Based on Nitrile-Terminated Biphenyls: A Promising New Anchoring Group

• Published in: Journal of the American Chemical Society Vol. 133; no. 2; pp. 184 - 187
• Main Authors: Mishchenko, Artem, Zotti, Linda A, Vonlanthen, David, Bürkle, Marius, Pauly, Fabian, Cuevas, Juan Carlos, Mayor, Marcel, Wandlowski, Thomas
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 19.01.2011; Amer Chemical Soc
• Subjects: Biphenyl Compounds - chemistry; Chemistry; Chemistry, Multidisciplinary; Molecular Structure; Nitriles - chemistry; Physical Sciences; Quantum Theory; Science & Technology; CONDUCTANCE; TRANSPORT; ALIGNMENT; CHEMISTRY; RESISTANCE; ELECTRONICS; DEPENDENCE
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja107340t

We present a combined experimental and theoretical study of the electronic transport through single-molecule junctions based on nitrile-terminated biphenyl derivatives. Using a scanning tunneling microscope-based break-junction technique, we show that the nitrile-terminated compounds give rise to well-defined peaks in the conductance histograms resulting from the high selectivity of the N−Au binding. Ab initio calculations have revealed that the transport takes place through the tail of the LUMO. Furthermore, we have found both theoretically and experimentally that the conductance of the molecular junctions is roughly proportional to the square of the cosine of the torsion angle between the two benzene rings of the biphenyl core, which demonstrates the robustness of this structure−conductance relationship.