Sub-nanometer supramolecular rectifier based on the symmetric building block with destructive σ-interference

Molecular rectifier, as a basic function of molecular electronic devices, has attracted extensive attention for the opportunity in constructing sub-nanometer electronic devices. However, tunneling leakage current has a significant contribution as electronic devices shrink in size, which leads to a challenge in fabricating molecular rectifiers at the sub-nanometer scale. Here, we experimentally demonstrate a sub-nanometer molecular rectifier based on the supramolecular junction assembled between water and 1,4-diazabicyclo[2.2.2]octane (DABCO) molecule. The charge transport through DABCO and corresponding supramolecular junctions exhibits destructive σ -interference, ensuring a sharp conductance variation for transmission modulation. The supramolecular interaction between DABCO and water readily introduces the asymmetric electrode-molecule interaction, which combines with the destructive σ -interference to support the sub-nanometer rectification.