Letter abstract
Nature Materials 8, 41 - 46 (2009)
Published online: 16 November 2008 | doi:10.1038/nmat2332
Subject Categories: Polymers | Biomedical materials
Highly conductive 
40-nm-long molecular wires assembled by stepwise incorporation of metal centres
Nunzio Tuccitto1, Violetta Ferri2, Marco Cavazzini3, Silvio Quici3, Genady Zhavnerko1, Antonino Licciardello1 & Maria Anita Rampi2
One of the main goals of molecular electronics is to achieve electronic functions from devices consisting of tailored organic molecules connecting two metal electrodes. The fabrication of nanometre-scale spaced electrodes still results in expensive, and often scarcely reproducible, devices1, 2, 3, 4. On the other hand, the 'conductance' of long organic molecules—generally dominated by the tunnelling mechanism—is very poor5, 6, 7, 8, 9. Here, we show that by incorporating a large number of metal centres into rigid molecular backbones we can obtain very long (up to 40 nm) and highly 'conductive' molecular wires. The metal-centre molecular wires are assembled in situ on metal surfaces via a sequential stepwise coordination of metal ions by terpyridine-based ligands10, 11. They form highly ordered molecular films of elevated mechanical robustness. The electrical properties, characterized by a junction based on Hg electrodes5, 6, indicate that the 'conductance' of these metal-centre molecular wires does not decrease significantly even for very long molecular wires, and depends on the nature of the incorporated redox centre. The outstanding electrical and mechanical characteristics of these easy-to-assemble molecular systems open the door to a new generation of molecular wires, able to bridge large-gap electrodes, and to form robust films for organic electronics.
- Dipartimento di Chimica, Università degli Studi di Catania, 95125, Catania, Italy
- Dipartimento di Chimica, Università di Ferrara, 44100 Ferrara, Italy
- CNR—Istituto di Scienze e Tecnologie Molecolari, 20133 Milano, Italy
Correspondence to: Antonino Licciardello1 e-mail: alicciar@unict.it
Correspondence to: Maria Anita Rampi2 e-mail: rmp@unife.it
