H-atom relay reactions in real space.

Area of Science:

• Surface science
• Molecular dynamics
• Physical chemistry

Background:

• Hydrogen bonds facilitate proton and hydrogen atom transfer between molecules.
• The relay mechanism, involving sequential H-atom transfer along hydrogen bonds, is vital in functional compounds.

Purpose of the Study:

• To develop a real-space observation test-bed for H-atom relay reactions at the single-molecule level.
• To investigate the controllability and reversibility of H-atom transfer along hydrogen-bonded chains.

Main Methods:

• Utilizing a scanning tunneling microscope (STM) to construct and operate a single-molecule test-bed.
• Inducing and observing H-atom transfer via inelastic electron tunneling.
• Performing ab initio calculations to analyze adsorption, vibrational modes, and reaction pathways.

Main Results:

• Demonstrated controllable and reversible H-atom transfer along hydrogen-bonded chains on a Cu(110) surface.
• Showcased vibrational excitation by inelastic tunneling electrons as the trigger for H-atom transfer.
• Obtained a detailed microscopic understanding of the elementary processes involved.

Conclusions:

• The STM provides a powerful platform for studying single-molecule H-atom relay reactions.
• Inelastic electron tunneling can precisely control molecular vibrations to initiate H-atom transfer.
• This work offers fundamental insights into hydrogen bond dynamics and chemical reactions at the molecular level.