Martín, Santiago and Grace, Iain and Bryce, Martin R. and Wang, Changsheng and Jitchat, Rukkiat and Batsanov, Andrei S. and Higgins, Simon J. and Lambert, Colin and Nichols, Richard J. (2010) Identifying Diversity in Nanoscale Electrical Break Junctions. Journal of the American Chemical Society, 132 (26). 9157–9164. ISSN 1520-5126
Full text not available from this repository.Abstract
The realization of molecular-scale electronic devices will require the development of novel strategies for controlling electrical properties of metal|molecule|metal junctions, down to the single molecule level. Here, we show that it is possible to exert chemical control over the formation of metal|molecule...molecule|metal junctions in which the molecules interact by π-stacking. The tip of an STM is used to form one contact, and the substrate the other; the molecules are conjugated oligophenyleneethynylenes (OPEs). Supramolecular π−π interactions allow current to flow through the junction, but not if bulky tert-butyl substituents on the phenyl rings prevent such interactions. For the first time, we find evidence that π-stacked junctions can form even for OPEs with two thiol contacts. Furthermore, we find evidence for metal|molecule|metal junctions involving oligophenyleneethynylene monothiols, in which the second contact must be formed by the interaction of the π-electrons of the terminal phenyl ring with the metal surface.