Identifying multiple configurations of complex molecules on metal surfaces.

Area of Science:

• Surface science
• Physical chemistry
• Materials science

Background:

• Experimental identification of molecular configurations in diffusion processes of large molecules at solid surfaces is challenging.
• Controlling self-assembly and resulting structures requires understanding molecular motion and configurations.

Purpose of the Study:

• To provide an overview of state-of-the-art techniques for identifying molecular configurations in motion.
• To review conventional tools, scanning probe microscopy, and a novel combined methodology.

Main Methods:

• Review of conventional techniques: low-energy electron diffraction and IR/Raman spectroscopy.
• Review of scanning probe microscopy for molecular configuration identification.
• Detailed review of a methodology combining time-resolved tunneling spectroscopy and density functional theory calculation.

Main Results:

• The combined methodology was successfully applied to (t-Bu)₄ -ZnPc and FePc systems.
• Molecular rotation and lateral diffusion on the Au(111) surface were analyzed.

Conclusions:

• The reviewed techniques offer insights into molecular configurations during diffusion.
• The combined time-resolved tunneling spectroscopy and DFT approach is effective for studying molecular dynamics at surfaces.