Stereoelectronic Effect-Induced Conductance Switching in Aromatic Chain Single-Molecule Junctions

Area of Science:

• Molecular electronics
• Organic functional materials
• Single-molecule junctions

Background:

• Biphenyl is a fundamental unit in organic electronics, but its conformational effects on charge transport remain poorly understood.
• Investigating single-molecule junctions provides a platform to study fundamental structure-property relationships.

Discussion:

• We established the stereoelectronic effect of biphenyl conformation on electrical conductance using graphene-molecule junctions.
• Phenyl twisting in hexaphenyl chains creates distinct electronic states, influencing charge transport.
• Temperature-dependent experiments and theoretical calculations confirm the link between conformation and conductance.

Key Insights:

• Molecular conformation significantly impacts electrical transport properties at the single-molecule level.
• The degree of conjugation, modulated by phenyl twisting, dictates the observed conductance states.
• Stochastic switching between high and low conductance states is directly linked to intramolecular dynamics.

Outlook:

• Findings offer insights for designing novel organic electronic and optoelectronic devices.
• Precise control over molecular conformation can lead to tunable single-molecule electronics.
• This work paves the way for advanced molecular switches and sensors.