Real-Space Investigation of the Multiple Halogen Bonds by Ultrahigh-Resolution Scanning Probe Microscopy.

Area of Science:

• Chemical Physics
• Surface Science
• Supramolecular Chemistry

Background:

• Understanding intermolecular bonds is crucial in chemistry.
• Real-space atomic information provides insights into molecular interactions.
• Halogen bonding is a significant noncovalent interaction.

Purpose of the Study:

• To investigate the nature of intermolecular bonds in real-space.
• To characterize the formation of molecular clusters (monomer, dimer, trimer, tetramer) on Au(111).
• To demonstrate the capability of nc-AFM/LT-STM for studying complex supramolecular assemblies.

Main Methods:

• Non-contact atomic force microscopy (nc-AFM) for atomic resolution imaging.
• Low-temperature scanning tunneling microscopy (LT-STM) for surface analysis.
• Density Functional Theory (DFT) calculations to support experimental findings.

Main Results:

• Acquisition of real-space atomic information of molecular clusters on Au(111).
• Identification of diverse halogen bonds driving molecular cluster formation.
• DFT calculations confirmed three distinct halogen bonding interactions involving Br-atoms.

Conclusions:

• nc-AFM and LT-STM enable real-space investigation of multiple halogen bonds.
• The study highlights the potential of these techniques for analyzing other intermolecular bonds.
• Provides a foundation for understanding complex supramolecular assemblies at the atomic level.