Figure 2: Sketch of the energetic level of the molecular device.

(a) Sketch of the energetic level of the molecular device when negative (−1 V) is applied on the Pt tip (see details in Supplementary Information). (b) Same as a with 0 V applied on the tip. (c) Same as a with −1 V applied on the tip. (d) Same as a with +1 V applied on the tip. We considered a coupling parameter of 0.8 to the Fc from the gold atom (80% of the potential drop occurs in the alkyl chain) to calculate the energy shift of the HOMO levels in the junction (see Supplementary Fig. 6 for details).