On-Surface Molecular Recognition Driven by Chalcogen Bonding

Area of Science:

• Supramolecular chemistry
• Surface science
• Materials chemistry

Background:

• Chalcogen bonding interactions (ChBIs) are crucial for creating ordered assemblies in various states.
• The potential of ChBIs for engineering molecular self-assembly on surfaces remains largely unexplored.

Purpose of the Study:

• To demonstrate for the first time that ChBIs can govern molecular self-assembly on surfaces.
• To investigate the role of specific molecular designs in achieving ordered on-surface assemblies via ChBIs.

Main Methods:

• Utilized scanning tunneling microscopy (STM) to visualize on-surface molecular arrangements.
• Employed ab initio calculations to understand the underlying interaction mechanisms.
• Synthesized and studied pyrenyl derivatives with chalcogenazolo pyridine motifs and reference compounds.

Main Results:

• Achieved the first demonstration of on-surface molecular recognition solely driven by ChBIs.
• Observed noncovalent chiral dimerization of a pyrenyl derivative on the Au(111) surface.
• Identified double Ch···N interactions involving Te- or Se-containing chalcogenazolo pyridine motifs as the key interaction.

Conclusions:

• Chalcogen bonding interactions are effective in directing molecular self-assembly on surfaces.
• The presence of the pyridyl moiety in chalcogenazolo pyridine derivatives is essential for forming regular, ordered on-surface assemblies.
• This work opens new avenues for designing functional molecular architectures on surfaces using ChBIs.