Control of Molecular Orientation in Single-Molecule Junction with Tripodal Triptycene Anchoring Unit: Toward Simple and Facile Single-Molecule Diode

We report a simple and facile procedure to control molecular orientation in a single-molecule junction and relevant rectification properties. Rectification properties of single-molecule junctions consisting of tripodal triptycene and C60 moieties at the termini that couple to the Au electrodes were determined using the break junction method. Because of the strong affinity of the tripodal triptycene moiety to the Au electrode, the molecular orientation and the related rectification direction are uniquely determined. Statistical analysis of the I–V curves of the single-molecule diode reveals the robustness of the rectification behavior with a statistically significant rectification ratio of 1.7.