Strain-Induced Isomerization in One-Dimensional Metal-Organic Chains

Area of Science:

• Surface science
• Materials chemistry
• Nanotechnology

Background:

• Mechanical strain offers novel synthetic routes for functional molecules and materials.
• Applying strain engineering to bottom-up on-surface synthesis of nanostructures remains challenging.

Purpose of the Study:

• To investigate internal strain-induced skeletal rearrangement in one-dimensional metal-organic chains (MOCs) on a metal surface.
• To explore the mechanism of atom shifts and bond cleavage during MOC rearrangement.

Main Methods:

• On-surface synthesis of MOCs on Cu(111) at room temperature.
• Copper-catalyzed debromination of organic monomers to form diradicals.
• Bond-resolved non-contact atomic force microscopy (nc-AFM).
• Density functional theory (DFT) calculations.

Main Results:

• Successfully induced skeletal rearrangement of 1D MOCs via concurrent atom shift and bond cleavage on Cu(111).
• Observed Cu-catalyzed debromination leading to diradical formation and subsequent MOC assembly.
• Identified strain relief as the driving force for rearrangement, involving H shifts and Cu adatom migration.
• Achieved energetically favorable registry of the MOC backbone with the Cu(111) substrate.

Conclusions:

• Demonstrated a novel strain-induced structural rearrangement mechanism in 1D MOCs.
• This finding expands the possibilities for on-surface synthesis of functional materials and quantum nanostructures.
• Provides a new strategy for designing and fabricating well-defined nanostructures using mechanical strain.