A Superatomic Dimer with Massive Spin Magnetic and Internal Electric Dipole Moments

Ligated metal-chalcogenide clusters have attracted considerable interest due to the recent developments in the synthesis process and their assembly into solids. In this work, the electronic and magnetic properties of the Fe₆S₈ cluster attached with ligands and the fused superatomic dimer are investigated using the first-principles density functional theory. It is shown that the redox properties of the Fe₆S₈ cluster can be effectively controlled by altering the nature of the attached ligands. Donor ligands such as phosphines reduce the ionization energy of the Fe₆S₈ cluster, whereas the acceptor ligands such as CO increase the electron affinity. Such variation in the redox properties of the Fe₆S₈ cluster is the result of the ligand-induced shift in the cluster’s electronic levels, so the occupation number remains mostly unaffected, leading to only marginal variation in the spin magnetic moment of the cluster. The fusion of two Fe₆S₈ clusters decorated by unbalanced ligands forms a superatomic dimer, which exhibits rare features: a massive dipole moment and a large spin magnetic moment. The resulting superatomic dimer offers an exciting motif for spintronics-related applications.