Universal inter-molecular radical transfer reactions on metal surfaces

Area of Science:

• Supramolecular Chemistry
• Surface Science
• Organic Synthesis

Background:

• On-surface synthesis enables low-dimensional supramolecular structure preparation.
• Surface-stabilized radicals are typically less reactive due to conduction band screening.
• Reactions catalyzed by surface radicals are infrequently documented.

Purpose of the Study:

• To describe intermolecular radical transfer reactions on metal surfaces.
• To steer alkyne coupling from non-dehydrogenated to dehydrogenated products.
• To establish a pathway for producing low-dimensional organic materials.

Main Methods:

• Utilizing aryl halide precursors for alkyne coupling reactions.
• Employing surface-sensitive technologies for mechanistic studies.
• Performing density functional theory (DFT) calculations to elucidate reaction pathways.

Main Results:

• Demonstrated intermolecular radical transfer reactions on metal surfaces.
• Achieved dehydrogenated coupling of terminal alkynes, forming alkynyl-metal-alkynyl bonds.
• Confirmed the universality of this reaction mechanism across different metal surfaces.

Conclusions:

• On-surface radical transfer reactions offer a novel synthetic route.
• This mechanism overcomes limitations of surface-stabilized radical reactivity.
• Enriches the on-surface synthesis toolbox for advanced materials development.