Steering on-surface polymerization through coordination with a bidentate ligand.

Area of Science:

• Surface science and nanotechnology
• Supramolecular chemistry
• Materials science

Background:

• On-surface synthesis enables the construction of complex molecular architectures.
• Phenanthroline derivatives are versatile building blocks for coordination chemistry and materials.
• Controlling polymerization pathways is crucial for designing functional nanostructures.

Purpose of the Study:

• To investigate the formation of double-chain structures from a bromine-functionalized phenanthroline precursor on Au(111).
• To elucidate the competing reaction mechanisms, specifically metal-ligand coordination versus C-C coupling, during on-surface polymerization.
• To establish a new strategy for controlling on-surface polymerization for nanostructure fabrication.

Main Methods:

• Fabrication of double-chain structures on Au(111) using a bromine-functionalized phenanthroline precursor.
• Molecular-level characterization using scanning tunneling microscopy (STM) imaging.
• Theoretical investigation employing density functional theory (DFT) calculations.

Main Results:

• Successful fabrication of a double-chain structure on the Au(111) surface.
• Identification of a competitive interplay between on-surface metal-ligand coordination and precursor C-C coupling.
• Demonstration of distinct reaction pathways influencing the resulting nanostructure.

Conclusions:

• The study reveals a competition between metal-ligand coordination and C-C coupling in on-surface polymerization of phenanthroline derivatives.
• This work provides a novel strategy for controlling polymerization on surfaces.
• The findings are relevant for the rational design and construction of advanced nanostructures.