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Atomically Precise Engineering of Single-Molecule Stereoelectronic Effect.

Linan Meng1,2, Na Xin3, Jinying Wang3

  • 1Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P. R. China.

Angewandte Chemie (International Ed. in English)
|March 2, 2021
PubMed
Summary
This summary is machine-generated.

Single-molecule junctions exhibit bistability due to phenyl ring movement. Introducing an azobenzene unit allows precise control over charge transport, enabling new molecular devices.

Keywords:
azobenzenefunctionalizationrotation barriersstereoelectronic effectsterphenyl rings

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Area of Science:

  • Molecular electronics
  • Organic electronics
  • Nanoscale science

Background:

  • Charge transport in single-molecule junctions is highly sensitive to molecular structure and environment.
  • Terphenyl molecules show distinct conductance states linked to phenyl ring bistability.

Purpose of the Study:

  • To investigate how an azobenzene unit influences charge transport in a terphenyl molecule.
  • To explore the stereoelectronic effects of azobenzene isomerization on molecular conformation and conductance.

Main Methods:

  • Atomically precise side-functionalization of a terphenyl molecule with an azobenzene unit.
  • Experimental measurements of charge transport in single-molecule junctions.
  • Theoretical calculations to analyze stereoelectronic effects and conformational changes.

Main Results:

  • Azobenzene isomerization (trans/cis) subtly controls the dihedral angle and rotation barrier between terphenyl rings.
  • This modulation of molecular conformation affects charge transport through a single-molecule stereoelectronic effect.
  • The effect is localized, with phenyl rings distant from the azobenzene unit remaining largely unaffected.

Conclusions:

  • Azobenzene isomerization provides a precise mechanism to tune charge transport in molecular junctions.
  • This tunability is key for developing advanced single-molecule memories, switches, and sensors.
  • Stereoelectronic effects offer a new pathway for designing responsive molecular systems.