Self-assembly of structurally rigid diamondoid esters on a HOPG surface.

Area of Science:

• Materials Science
• Nanotechnology
• Surface Chemistry

Background:

• Characterizing non-aromatic organic molecules on surfaces is challenging.
• Diamondoid esters lack long alkyl chains, complicating assembly studies.

Purpose of the Study:

• To study the on-surface self-assembly of diamondoid esters.
• To develop a general approach for characterizing non-aromatic molecules on surfaces.
• To understand the interactions driving self-assembly.

Main Methods:

• Atomic Force Microscopy (AFM) for imaging surface domains.
• Semi-empirical quantum mechanical calculations (GFN2-xTB) for determining molecular orientations.
• Synergistic experimental and computational analysis.

Main Results:

• Visualized on-surface domains of diamondoid esters.
• Identified stable on-surface molecular orientations.
• Revealed London dispersion interactions drive molecular chain formation.
• Observed distinct domains with structural periodicity.

Conclusions:

• Established a method for characterizing non-aromatic molecules on surfaces.
• Demonstrated self-assembly of diamondoid esters driven by London dispersion forces.
• Provided insights into nanomaterial design with non-aromatic compounds.