Tripodal Triptycenes as a Versatile Building Block for Highly Ordered Molecular Films and Self-Assembled Monolayers

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Nanotechnology

Background:

• Designing molecular assemblies requires control over building block choice and packing.
• Tripodal triptycenes offer predictable packing and multiple functionalization sites.
• These molecules enable the formation of 2D sheets and 1D stacking into "2D+1D" structures.

Purpose of the Study:

• To explore the self-assembly capabilities of tripodal triptycenes on diverse substrates.
• To investigate the functionalization of tripodal triptycenes for specific applications.
• To assess the utility of tripodal triptycene-based SAMs in nanofabrication and device performance.

Main Methods:

• Synthesis of functionalized tripodal triptycenes.
• Formation of self-assembled monolayers (SAMs) on Au(111), Ag(111), and indium tin oxide.
• Characterization of molecular packing and film properties.
• On-surface click reactions for layer deposition.
• Electron beam lithography (EBL) for nanofabrication.

Main Results:

• Tripodal triptycenes form stable 2D nested hexagonal packing and 1D stacking.
• Robust molecular films and SAMs were achieved on polymer and inorganic substrates.
• Functionalized SAMs enabled studies of charge transfer, redox reactions, and molecular rectification.
• On-surface click reactions facilitated successive molecular layer deposition.
• Tripodal triptycene SAMs demonstrated utility as negative resists for EBL, forming novel carbon nanomembranes (CNMs).

Conclusions:

• Tripodal triptycenes are versatile building blocks for constructing ordered molecular assemblies.
• Functionalized tripodal triptycene SAMs offer platforms for advanced molecular electronics and single-molecule studies.
• These SAMs show significant potential in nanofabrication, particularly for creating low-density carbon nanomembranes.