Building a 22-ring nanographene by combining in-solution and on-surface syntheses.

Area of Science:

• Materials Science
• Organic Chemistry
• Surface Science

Background:

• Graphene nanostructures are of great interest for their unique electronic and optical properties.
• Precise synthesis of large, well-defined polycyclic aromatic hydrocarbons remains a significant challenge.

Purpose of the Study:

• To synthesize a specific nanographene molecule with a defined structure.
• To characterize the structural and electronic properties of the synthesized nanographene.

Main Methods:

• Utilized palladium-catalyzed cycloaddition in solution.
• Employed on-surface gold-promoted cyclodehydrogenation for final structure formation.
• Characterized the molecule using scanning probe microscopy with atomic resolution.
• Corroborated experimental findings with theoretical modeling.

Main Results:

• Successfully synthesized a nanographene composed of 22 fused benzene rings (C66H24).
• The molecule exhibits three-fold symmetry.
• Atomic resolution scanning probe microscopy confirmed the precise molecular structure.
• Theoretical modeling supported the experimental observations and electronic property predictions.

Conclusions:

• A novel, precisely structured nanographene molecule has been synthesized.
• The combination of in-solution and on-surface chemistry enables the construction of complex organic architectures.
• The characterized C66H24 molecule serves as a model system for understanding the properties of larger graphene nanostructures.