Exchange Interactions and Intermolecular Hybridization in a Spin-¹/₂ Nanographene Dimer.

Area of Science:

• Materials Science
• Quantum Chemistry
• Nanotechnology

Background:

• Phenalenyl is a triangular nanographene radical with S = 1/2 spin.
• The retention of open-shell character in networks is key for spintronics.

Purpose of the Study:

• Synthesize and characterize the phenalenyl dimer.
• Investigate interphenalenyl exchange interactions and their impact on spin states.
• Explore the potential for bottom-up synthesis of spin lattices.

Main Methods:

• In-solution synthesis followed by on-surface activation.
• Characterization using inelastic electron tunneling spectroscopy (IETS) on Au(111) and NaCl.
• Analysis of spin excitation energies and bias asymmetry.

Main Results:

• Successful synthesis of the phenalenyl dimer.
• Observed singlet-triplet excitation energies of 48 meV (on Au(111)) and 41 meV (on NaCl).
• Identified significant electron-phonon coupling and hybridization effects influencing spin exchange.

Conclusions:

• The phenalenyl dimer retains its radical character and exhibits spin exchange.
• On-surface hybridization significantly renormalizes spin excitation energies.
• This work enables the bottom-up construction of S = 1/2 spin lattices with tunable exchange interactions.