Modulating Quantum Interference Between Destructive and Constructive States in Double N‐Substituted Single Molecule Junctions

Quantum interference (QI) plays a crucial role in determining the charge transport molecular devices. In this work, efficient modulation of QI meta-phenylene ethylene oligomer devices by double N-substitution strategy is demonstrated. By altering positions two N atoms central ring with respect to connecting sites, conductance can be tuned more than one order magnitude. Theoretical analysis, including magic ratio theory, orbital rule, and transmission simulations, reveals how synergistically modulate molecule between destructive constructive states. Remarkably, addition second atom does not simple reinforce effect first; contrast, it may completely cancel first. Understanding complex electronic interplay N-substituted molecules paves path toward utilization heterocyclic aromatic hydrocarbons electronics.