Modulation of destructive quantum interference by bridge groups in truxene-based single-molecule junctions

Electron transport properties of polycyclic truxene derivatives have been investigated by single molecule conductance measurement technique and theoretical study. Molecules with nitrogen and carbonyl substituents at the bridge site exhibit higher single-molecule conductances by almost one order of magnitude compared with non-substituented analogues. It can be ascribed that anti-resonance feature produced by destructive quantum interference (DQI) is alleviated and pushed away from the Fermi level. These findings provide an effective chemical strategy for manipulating the DQI behavior in single molecular devices.