Steering Large Magnetic Exchange Coupling in Nanographenes near the Closed-Shell to Open-Shell Transition

• DOI: 10.1021/jacs.2c11431
• Publication Date: 2023-01-28T13:56:50Z
• Authors: Kalyan Biswas; Diego Soler; Shantanu Mishra; Qiang Chen; Xuelin Yao; Ana Sánchez-Grande; Kristjan Eimre; Pingo Mutombo; Cristina Martín-F...; Koen Lauwaet; José M. Gallego; Pascal Ruffieux; Carlo A. Pignedoli; Klaus Müllen; Rodolfo Miranda; José I. Urgel; Akimitsu Narita; Roman Fasel; Pavel Jelínek; David Écija
• Keywords: Open shell; Magnetism

The design of open-shell carbon-based nanomaterials is at the vanguard materials science, steered by their beneficial magnetic properties like weaker spin-orbit coupling than that transition metal atoms and larger spin delocalization, which are potential relevance for future spintronics quantum technologies. A key parameter in exchange (MEC) between unpaired spins, should be large enough to allow device operation practical temperatures. In this work, we theoretically experimentally explore three distinct families nanographenes (NGs) (A, B, C) featuring majority zigzag peripheries. Through many-body calculations, identify a from closed-shell ground state an upon increase molecular size. Our predictions indicate largest MEC NGs occurs proximity states. Such corroborated on-surface syntheses structural, electronic, characterizations (A[3,5], B[4,5], C[4,3]), smallest systems respective chemical thus located closest boundary. Notably, two (B[4,5] C[4,3]) feature record values (close 200 meV) measured on Au(111) surface. strategy maximizing provides perspectives designing carbon with robust