Electron and Spin Delocalization in [Co₆Se₈(PEt₃)₆]^0/+1 Superatoms

Abstract

Molecular clusters can function as nanoscale atoms/superatoms, assembling into superatomic solids, a new class of solid‐state materials with designable properties through modifications on superatoms. To explore possibilities on diversifying building blocks, here we thoroughly studied one representative superatom, Co6Se8(PEt3)6. We probed its structural, electronic, and magnetic properties and revealed its detailed electronic structure as valence electrons delocalize over inorganic [Co6Se8] core while ligands function as an insulated shell. 59Co SSNMR measurements on the core and 31P, 13C on the ligands show that the neutral Co6Se8(PEt3)6 is diamagnetic and symmetric, with all ligands magnetically equivalent. Quantum computations cross‐validate NMR results and reveal degenerate delocalized HOMO orbitals, indicating aromaticity. Ligand substitution keeps the inorganic core nearly intact. After losing one electron, the unpaired electron in [Co6Se8(PEt3)6]+1 is delocalized, causing paramagnetism and a delocalized electron spin. Notably, this feature of electron/spin delocalization over a large cluster is attractive for special single‐electron devices.