Mechanism of enhanced rectification in unimolecular Borromean ring devices

We have studied charge transport through individual Borromean ring complexes, both with and without anchor groups, in gated double-barrier tunneling junctions (DBTJs) formed using the electrical breakjunction technique on gold nanowires. While common single-molecule device characteristics can be observed with either form of the Borromean rings, the complexes with anchor groups show a strong rectification of conduction in a relatively high percentage of samples. We present our data along with a simple model underlining the mechanism by which the arrangement and composition of the weakly bonding anchor groups attached to the electroactive element may promote a device configuration resulting in rectification.