One-dimensional molecular chains formed by Sierpiński triangles on Au(111)

Area of Science:

• Surface science
• Supramolecular chemistry
• Nanotechnology

Background:

• Self-assembly of molecules on surfaces is crucial for creating ordered nanostructures.
• Fractal geometries offer unique properties for molecular design.
• Coordination interactions are key to stabilizing molecular assemblies.

Purpose of the Study:

• To synthesize and characterize one-dimensional molecular chains using Sierpiński triangles as building blocks.
• To investigate the role of coordination interactions in fractal self-assembly.
• To explore the influence of molecular coverage on the formation of ordered structures.

Main Methods:

• Low-temperature scanning tunneling microscopy (LT-STM) for surface imaging.
• Synthesis of molecular building blocks: 1,3-bi(4-pyridyl) benzene (BPyB) and Cobalt (Co) atoms.
• Controlled deposition of molecules and metal atoms on Au(111) surface.

Main Results:

• Successfully prepared fractal Sierpiński triangles of high orders on Au(111).
• Stabilized Sierpiński triangles via coordination bonds between BPyB and Co atoms.
• Observed the formation of two distinct types of one-dimensional molecular chains at high molecular coverages.

Conclusions:

• High molecular coverage and favorable molecular size-to-surface lattice matching promote the formation of molecular chains.
• Coordination-driven self-assembly enables the creation of complex fractal nanostructures.
• The study demonstrates a pathway for constructing ordered one-dimensional molecular architectures with fractal motifs.