Theoretical investigation on the structure, stability and superhalogen properties of OsFn (n = 1–7) species

• Density functional calculations have been carried out on OsFn species for n = 1–7.
• The maximum oxidation state of Os is found to be limited to +6.
• OsFn species behave as superhalogens for n ≥ 4.
• Interaction of an alkali metal, K with OsF4 superhalogen forms a stable complex compound, KOsF4.

Density functional investigations on neutral and anionic OsFn species (n = 1–7) have been performed in various spin states. It is revealed that OsFn species are stable in neutral form up to n = 6 but in anions up to n = 7, thus limiting the maximum oxidation state of Os to well established value of +6. Jahn–Teller distortions are seen in OsFn species for n = 4 and 6. The superhalogen properties of OsFn species are explored by their high adiabatic electron affinities for n ≥ 4. The interaction between OsFn superhalogen and an alkali metal atom is demonstrated by considering K and OsF4 which leads to the formation of stable KOsF4 complex. In this complex, the behavior of OsF4 unit is very similar to fluorine, F atom.

The plot shows that the adiabatic electron affinity of OsFn increases with the increase in F atoms and reaches a peak value of 7.68 eV for n = 7. The large electron affinities of OsFn as compared to halogen suggest the superhalogen behavior of these species for n ≥ 4.Figure optionsDownload as PowerPoint slide