Electric-field control of single-molecule tautomerization

Area of Science:

• Surface science
• Molecular electronics
• Physical chemistry

Background:

• Electric fields influence molecular charge distribution, crucial for single-molecule experiments.
• Precisely controlling electric fields in interfacial chemical reactions is challenging.

Purpose of the Study:

• To demonstrate a method for controlling molecular reactions with external electric fields.
• To investigate the effect of electric fields on intramolecular hydrogen atom transfer in a metal-free macrocycle.

Main Methods:

• Combined graphene field-effect transistor (GFET) with a gate-tunable scanning tunneling microscope (STM).
• Utilized this integrated system to apply and control external electric fields at the molecular level.

Main Results:

• Successfully controlled intramolecular hydrogen atom transfer in a metal-free macrocycle using an external electric field.
• Observed a decrease in the energetic barrier for tautomerization with increasing electric field strength.
• Experimental findings were consistent with theoretical calculations.

Conclusions:

• The developed GFET-STM technique enables precise electric field control over molecular reactions.
• Electric fields can be engineered to modulate molecular switching mechanisms.
• This approach has potential applications in designing nanoscale electronic devices.