Supramolecular Tessellations at Surfaces by Vertex Design

Area of Science:

• Surface Science
• Materials Chemistry
• Supramolecular Chemistry

Background:

• Organic molecule assembly on surfaces is key for designing advanced materials.
• Controlling complex supramolecular self-assemblies and their tessellations remains a challenge.
• Existing methods offer limited ability to steer systems between different supramolecular arrangements.

Purpose of the Study:

• To demonstrate a method for controlling molecular symmetry to influence surface tessellations.
• To achieve stepwise reduction and restoration of molecular symmetry.
• To generate a series of supramolecular tessellations reflecting controlled molecular symmetry.

Main Methods:

• Deposition of 4,4'-dihydroxybiphenyl on a silver (Ag(111)) surface.
• Annealing at specific temperatures to induce stepwise dehydrogenation of hydroxyl groups.
• Characterization using scanning tunneling microscopy (STM) and synchrotron radiation photoemission spectroscopy (SRPES).

Main Results:

• Stepwise reduction and restoration of molecular symmetry were achieved by controlled annealing.
• Variations in molecular symmetry directly impacted vertex symmetry in the self-assembled structures.
• A series of distinct supramolecular tessellations were generated, reflecting the altered molecular symmetry.
• Changes in tessellation vertex symmetry were confirmed via STM and SRPES.

Conclusions:

• The study successfully demonstrates control over molecular symmetry to steer supramolecular tessellations.
• This control over vertex geometry advances the design principles for complex self-assembled architectures.
• The findings contribute to developing functional surfaces with tailored molecular arrangements.