Prediction of the Iron-Based Polynuclear Magnetic Superhalogens with Pseudohalogen CN as Ligands

Abstract

To explore stable polynuclear magnetic superhalogens, we perform an unbiased structure search for polynuclear iron-based systems based on pseudohalogen ligand CN using the CALYPSO method in conjunction with density functional theory. The superhalogen properties, magnetic properties, and thermodynamic stabilities of neutral and anionic Fe(CN) and Fe(CN) clusters are investigated. The results show that both of the clusters have superhalogen properties due to their electron affinities (EAs) and that vertical detachment energies (VDEs) are significantly larger than those of the chlorine element and their ligand CN. The distribution of the extra electron analysis indicates that the extra electron is aggregated mainly into pseudohalogen ligand CN units in Fe(CN) and Fe(CN) cluster. These features contribute significantly to their high EA and VDE. Besides superhalogen properties, these two anionic clusters carry a large magnetic moment just like the FeF cluster. Additionally, the thermodynamic stabilities are also discussed by calculating the energy required to fragment the cluster into various smaller stable clusters. It is found that Fe(CN) is the most favorable fragmentation product for anionic Fe(CN) and Fe(CN) clusters, and both of the anions are less stable against ejection of Fe atoms than Fe(CN).

Superhalogen Species of Titanium Oxide Related Clusters Generated by Laser Ablation

“…For instance, the superhalogen properties of titanium-related species are very limited . Since a plenty of studies have demonstrated that polynuclear clusters can form superhalogens more effectively, ,,,− it is very interesting to see whether the polynuclear clusters of titanium can behave as a new class of superhalogens.…”

Superhalogen Anions Supported by the Systems Comprising Alternately Aligned Boron and Nitrogen Central Atoms

“…However, the number of ligands bound to a single central atom cannot be increased beyond certain values (mostly due to destabilizing valence repulsion effects and steric hindrance). Hence, polynuclear superhalogen anions matching the (M n X n×k+1 ) – formula in which an excess electron density is expected to delocalize over n× k +1 electronegative ligands have been extensively studied in recent years ( Alexandrova et al, 2004 ; Anusiewicz and Skurski, 2007 ; Freza and Skurski, 2010 ; Sikorska and Skurski, 2012 ; Wileńska et al, 2014 ; Yin et al, 2014 ; Li et al, 2015a , 2015b , Li et al, 2015 M.-M. ; Czapla and Skurski, 2015 , 2018 ; Díaz-Tinoco and Ortiz, 2016a ; Díaz-Tinoco and Ortiz, 2016b ; Sun et al, 2016b ; Ding et al, 2017 ; Zhao et al, 2017 ; Anusiewicz et al, 2018 ; Cyraniak et al, 2019 ; Shi et al, 2019 ). Even though the polynuclear superhalogens investigated to date contain various central atoms (e.g., Li, Na, Mg, Ca, B, Al, Ge, Sn, P, Ti, Sb, As, V, In, Ta, Fe, Au, Pt), the systems utilizing nitrogen central atoms have not been proposed thus far.…”

Endohedral Metallofullerene M2@C80: A New Class of Magnetic Superhalogen

“…Such kind of clusters are regarded as superatoms. , They usually have high thermodynamic stability, providing an entirely new “third dimension” to the traditional periodic table of elements. , Compared with single atoms, one advantage of superatoms is that their physical and chemical properties can be easily controlled by varying their size and composition, which enables the bottom-up synthesis of materials with novel nanostructures and tailored properties. , Superhalogen is a typical class of superatom whose electron affinity (EA) is even larger than that of a chlorine atom, which has the largest EA in the elements table . A large variety of superhalogens have been discovered experimentally or theoretically. − In recent years, magnetic superatoms have attracted increasing research interests from the scientific community. − The general strategy for designing magnetic superatoms is based on transition-metal atoms that have partially filled localized d orbitals . For example, superatoms VNa 8 and VNa 9 have been found to behave like single Mn and Cr atoms, respectively .…”