Theoretical Search for an Iron‐Based Magnetic Superhalogen with Halogen or Interhalogen as Ligand

Abstract

By using density functional theory, we have investigated the geometrical structures, electrophilic properties, magnetic properties, and fragmentation channels of FeXn (X = Cl, Br; n = 1–6) clusters as well as the “mixed species” that contain interhalogen compounds. Our main objectives are to design new iron‐based magnetic superhalogens and to explore whether the interhalogen compounds are suitable for the superhalogen ligand. By calculating their adiabatic electron affinities (AEAs) and vertical detachment energies (VDEs), we found that both FeCln and FeBrn can be classified as superhalogens for n ≥ 3. Among mixed species, FeClF3, FeBrF3, FeClF5, and FeBrF5 are superhalogens, but their AEA values are still smaller than those of the correspondingly sized FeFn clusters. Their superhalogen properties are further supported by the natural population analysis (NPA) charge distribution and the HOMO of anions. However, in mixed species, the extra electron and HOMO do not uniformly delocalize over the different halogen atoms. This might be the reason why FeXYn possesses relatively small AEA values. In addition, we also studied the superhalogen salts formed with these superhalogen anions and Na+, which greatly enhance the reliability of our obtained superhalogens.

Iron-based magnetic superhalogens with pseudohalogens as ligands: An unbiased structure search

“…They found that the Fe 2 Cl 5 + possesses the stronger magnetic coupling, and the degree of spin delocalization is larger than that in Mn 2 Cl 5 − . Inspired by these results, we have performed investigations on iron-based magnetic superhalogens with halogen (F, Cl, and Br) 30 or interhalogen (ClF, ClF 3 , ClF 5 , BrF, BrF 3 , BrF 5 , and BrCl) 31 as ligand. However, most of the previous works of magnetic superhalogens are concentrated on halogen atoms as ligand.…”