An sp-sp²-hybridized molecular carbon allotrope C₁₆ flake

Area of Science:

• Materials Science
• Chemistry
• Nanotechnology

Background:

• Molecular carbon allotropes, such as C16 molecules, offer diverse isomeric possibilities beyond known structures like cyclo[16]carbon.
• Previous C16 isomers have been primarily theoretical predictions, lacking experimental synthesis and characterization.

Purpose of the Study:

• To synthesize and structurally characterize a novel graphene-shaped C16 isomer.
• To explore the potential of atom manipulation for creating complex carbon nanostructures.

Main Methods:

• Atom manipulation strategy involving the dehalogenation of a chlorinated pyrene precursor (C16Cl10).
• Synthesis and characterization performed on a bilayer sodium chloride (NaCl) surface atop a gold (Au(111)) substrate.
• Bond-resolved atomic force microscopy (AFM) for detailed structural analysis.

Main Results:

• Successful synthesis of a graphene-shaped C16 isomer, termed C16 flake.
• Experimental characterization confirmed the sp- and sp2-hybridized structure of the C16 flake.
• Theoretical calculations indicated an open-shell singlet ground state for the synthesized C16 flake.

Conclusions:

• The study reports the first experimental synthesis and characterization of a graphene-shaped C16 isomer.
• Atom manipulation provides a viable route for constructing specific molecular carbon allotropes.
• The findings open new avenues for exploring the properties and applications of C16 isomers.