Noble Gas Provides a Solution to the Synthesis-On-Inert-Surfaces Challenge for Extended Covalent Nanostructures

Area of Science:

• Materials Science
• Surface Chemistry
• Nanotechnology

Background:

• On-Surface Synthesis (OSS) typically utilizes metal surfaces, which can negatively impact nanostructure properties.
• Inert surfaces preserve nanostructure integrity but pose synthesis challenges due to high activation energies and reactant desorption.
• Premature desorption of reactants hinders thermally activated covalent coupling on inert substrates.

Purpose of the Study:

• To develop generic protocols for covalent coupling on inert surfaces in On-Surface Synthesis (OSS).
• To overcome the challenge of reactant desorption during synthesis on inert substrates.
• To enable the synthesis of functional nanostructures with preserved intrinsic properties.

Main Methods:

• Utilized 1,3,5-tris(4-mercaptophenyl)benzene (TMB) for coupling via carbon-sulfur-carbon thioether bonds.
• Employed annealing in a noble gas atmosphere instead of vacuum to kinetically inhibit reactant desorption.
• Performed covalent coupling on inert graphite and graphene surfaces.

Main Results:

• Demonstrated successful covalent coupling of TMB on inert graphite and graphene surfaces.
• Showed that annealing in a noble gas atmosphere significantly inhibits premature desorption of reactants.
• Established a method to facilitate On-Surface Synthesis (OSS) on weakly interacting surfaces.

Conclusions:

• Annealing in a noble gas atmosphere is an effective strategy to enable covalent coupling on inert surfaces.
• This approach preserves the intrinsic properties of synthesized nanostructures.
• The method holds generic potential for expanding On-Surface Synthesis (OSS) protocols to various coupling reactions.