Preprogrammed 2D folding of conformationally flexible oligoamides: foldamers with multiple turn elements

Area of Science:

• Supramolecular Chemistry
• Surface Science
• Organic Synthesis

Background:

• Controlling molecular conformation on surfaces is key for nanoscale precision patterning.
• Noncovalent interactions are crucial for directing self-assembly of molecular structures.
• Foldamers offer a versatile platform for designing complex molecular architectures.

Purpose of the Study:

• To design, synthesize, and investigate linear oligoamides (foldamers) for surface patterning.
• To explore the self-assembly behavior of these foldamers at the liquid-solid interface.
• To understand how molecular complexity influences supramolecular architecture.

Main Methods:

• Synthesis of a new class of extended foldamers with multiple turn elements.
• Scanning tunneling microscopy (STM) to investigate adsorption and self-assembly at the liquid-solid interface.
• Analysis of foldamer conformation and supramolecular assembly using submolecularly resolved STM images.

Main Results:

• Successful synthesis of foldamers with up to four turn elements.
• Observation of characteristic in-plane folding and self-assembly behavior.
• Demonstration that supramolecular complexity increases with the number of turn elements.

Conclusions:

• Foldamers exhibit predictable self-assembly and conformational behavior at the liquid-solid interface.
• The modular design allows for versatile surface patterning with molecular precision.
• Enthalpic and entropic factors influence the adsorption behavior of different foldamers.