Conductance of single 1,4-disubstituted benzene molecules anchored to Pt electrodes

Abstract

The authors have studied the conductance of a 1,4-disubstituted isocyanide(–NC) or thiol(–SH) benzene molecule anchored to two Pt electrodes. A single molecular junction showing a well-defined conductance value ($\sim 3\times {10}^{-2}{G}_0$ , $G_0=2e^2∕h$ ) was fabricated with the Pt electrodes. The conductance of the molecular junction was one order higher than the previously documented value using Au electrodes. These observations could be explained by differences in the local density of states of the contact metal atom at the Fermi level and the extent of the hybridization and energy difference between the molecular and metal orbitals. Further insight into the binding strengths of the metal-anchoring group bond was obtained by statistically analyzing the stretching length of the molecular junction.