Tuning the current rectification behavior of Rh-based molecular junctions by varying their supramolecular structures.

Molecular junctions with similar backbones, tunable chemical structures and controllable length are critical for the systematic study of the structure-functionality relationships of their charge transport behavior. Taking advantage of the feasibility and tunability of stepwise fabrication, we built series of asymmetric supramolecular SAMs on gold using Rh(OCCR) (Rh, R = CH, H, and F) as the building blocks and conjugated ,'-bidentate ligands (pyrazine (L), 4,4'-bipyridine (L) and 1,2-bis(4-pyridyl)ethene (L)) as the bridges. By varying the Rh units and bridging ligands, series of supramolecules with similar backbone and tunable chemical structures were assembled on gold.