Theoretical Study On Structures And Properties Of Two Kinds Of Typical Superhalogen Compounds

Clusters are of considerable interest in researches of inorganic chemistry and material chemistry, and play an important role in solid, surface physics, molecular physics, catalysis, etc. An exciting development of cluster chemistry is the discovery that clusters with certain size and com position can simulate the properties of the individual atoms in the periodic table. These groups of atoms are described as “superatom”. Superhalogen is an important subset of superatom.In this contribution, we presented a comparative study of two kinds of representative superhalogen compounds, namely hydrogenated superhalogens and lithiated superhalogens. The bonding properties, stability, geometrical features, NBO charge, HOMO-LUMO gaps, dissociation energies of these superatom compounds are investigated detailedly. The results may provide meaningful references for the design of new materials.Main conclusions are as follows:（1） Most of superhalogen clusters as a whole combine with Li atom through ionic bond（s）, just like a single halogen atom does. In contrast, the H atom tends to bind with superhalogen by covalent bond although a portion of superhalogens are broken upon hydrogenation.（2） The chemical stability of these species are explored by examining their possible dissociation channels and corresponding dissociation energies. The majority of studied compounds prefer to dissociate into neutral molecules instead of ion fragments, which is different from the dissociation manner of traditional acid and salt molecules. The large HOMO-LUMO gaps of these compounds also guarantee their stability.（3） All the lithiated superhalogens possess larger β0 and α0 values than their corresponding hydrogenated superhalogens. And the（MgCl₃）-Li molecule shows considerable β0 values of 1411.8 au..