Reversible coordination-induced spin-state switching in complexes on metal surfaces

Area of Science:

• Materials Science
• Surface Science
• Molecular Electronics

Background:

• Molecular spin switches are crucial for controlling spin polarization at molecule-metal interfaces, essential for molecular spintronics.
• Existing intrinsic spin switches often fragment or lose function on metal surfaces, while robust platforms require external ligands for switching.
• A need exists for integrated, robust molecular systems capable of reliable spin switching.

Purpose of the Study:

• To engineer robust metal-organic complexes with integrated, mechanically-driven spin switching functionality.
• To demonstrate reversible spin and coordination switching induced by electron injection on a metal surface.
• To assess the stability and potential applications of these novel molecular switching systems.

Main Methods:

• Design and synthesis of robust metal-organic complexes featuring a porphyrin ring with a mechanically moving axial ligand.
• Adsorption of the synthesized complexes onto a Silver(111) surface.
• Induction of spin and coordination switching via electron injection and characterization of the molecular states.

Main Results:

• Successful integration of spin switching functionality into robust metal-organic complexes.
• Demonstration of reversible, interlocked switching between spin and coordination states induced by electron injection on Ag(111).
• High stability of the switched molecular states, persisting for days at cryogenic temperatures (4 K).

Conclusions:

• The developed molecular platform offers a stable and robust approach to spin switching integrated within molecular complexes.
• Electron-induced mechanical movement of ligands enables reversible control over both spin and coordination states.
• This switching concept holds promise for advancing molecular spintronics devices and potentially controlling surface catalytic activity.