Abstract
The electrical transport properties of dodecanethiol (DT) and 2.5''-bis(acetylthio)-5.2'5'.2''-terthienyl (T3) embedded in metal-molecule-metal junctions are investigated. Scannning tunelling microscopy imaging and I- V curves recorded on mechanically breakable junctions allow us to observe a marked difference in the electrical behaviour of these molecules: in particular, steps have been observed in the I- V characteristics of gold-T3-gold junctions, which are not found in the gold-DT-gold ones.