Imaging single-molecule reaction intermediates stabilized by surface dissipation and entropy

Area of Science:

• Surface chemistry
• Heterogeneous catalysis
• Molecular dynamics

Background:

• Chemical reactions at interfaces are crucial for industry.
• Current methods often average molecular behavior, limiting detailed understanding.
• Investigating single-molecule reaction pathways provides deeper insights.

Purpose of the Study:

• To investigate the surface-catalyzed reaction of 1,2-bis(2-ethynyl phenyl)ethyne on Silver(100).
• To visualize and understand the dynamics of transient intermediates in chemical transformations.
• To elucidate the factors governing the kinetic stabilization of reaction intermediates.

Main Methods:

• Utilized non-contact atomic force microscopy (nc-AFM) for single-bond-resolved imaging.
• Performed theoretical simulations to analyze potential-energy landscapes and reaction pathways.
• Investigated energy dissipation to the substrate and entropic effects.

Main Results:

• Successfully imaged the chemical structure of metastable intermediates during the reaction.
• Identified that kinetic stabilization depends on both energy landscape and energy dissipation.
• Demonstrated the role of entropic changes in reaction pathway dynamics.

Conclusions:

• Microscopic insights into surface reactions can be obtained through advanced imaging and simulation.
• Rational design of heterogeneous catalysts can be achieved by understanding these molecular-level processes.
• This work provides a foundation for controlling complex organic reactions on catalyst surfaces.