The Mackay-type cluster [Cu43Al12](Cp*)12 Open-shell 67 electron superatom with emerging metal-like electronic structure

Abstract : The paramagnetic cluster [Cu Al ](Cp*) was obtained from the reaction of [CuMes] and [AlCp*] (Cp*=η -C Me ; Mes=mesityl). This all-hydrocarbon ligand-stabilized M magic atom-number cluster features a Mackay-type nested icosahedral structure. Its open-shell 67-electron superatom configuration is unique. Three unpaired electrons occupy weakly antibonding jellium states. The situation prefigures the formation of a conduction band, which is in line with the measured temperature-independent magnetism. Steric protection by twelve Cp* ligands suppresses the intrinsic polyradicalar reactivity of the Cu Al core.