PtX as the limit of high oxidation states in oxide–nitride species

Abstract

A series of pentaatomic species has been investigated theoretically with relativistic DFT using the M06-L functional with both ZORA scalar relativistic correction, and including spin–orbit coupling effects. The distorted quasi-octahedral local minima for PtNO₃⁺, PtN₂O₂ and PtN₃O⁻ corresponding to decavalent Pt were found to be unstable with respect to the elimination of O₂, NO or N₂. However, barriers surrounding these minima suggest that these species could be achieved under low-temperature conditions, similar to what was predicted for PtO₄²⁺ dications. Decavalent platinum sets the upper limit for high oxidation states of the chemical elements.