Halogen bonds as stabilizing interactions in a chiral self-assembled molecular monolayer

Area of Science:

• Materials Science
• Organic Electronics
• Supramolecular Chemistry

Background:

• Self-assembled monolayers (SAMs) are crucial for organic electronics.
• Controlling molecular organization at surfaces is key for device performance.
• Achiral molecules can form chiral structures through self-assembly.

Purpose of the Study:

• To investigate the self-assembly of an achiral organic semiconductor.
• To understand the driving forces behind the formation of ordered chiral monolayers.
• To explore the role of specific intermolecular interactions in directing molecular assembly.

Main Methods:

• Scanning Tunneling Microscopy (STM) for surface morphology analysis.
• Density Functional Theory (DFT) calculations for computational modeling.
• Synthesis and characterization of achiral organic semiconductor molecules.

Main Results:

• Formation of highly-ordered self-assembled monolayers.
• Observation of spontaneous, large single domains of chiral monolayers from achiral molecules.
• Identification of halogen bonds as the dominant interaction steering assembly.

Conclusions:

• Achiral organic molecules can form chiral supramolecular structures.
• Halogen bonding is a powerful tool for directing molecular self-assembly.
• This work provides insights into designing ordered organic electronic materials.