Oxidation State 10 Exists

In a recent paper, Wang et al. found an iridium‐containing compound with a formal oxidation state of 9. ⁵ This is the highest oxidation state ever found in a stable compound. To learn if this is the highest chemical oxidation state possible, Kohn–Sham density functional theory was used to study various compounds, including PdO₄²⁺, PtO₄²⁺, PtO₃F₂²⁺, PtO₄OH⁺, PtO₅, and PtO₄SH⁺, in which the metal has an oxidation state of 10. It was found that PtO₄²⁺ has a metastable state that is kinetically stable with a barrier height for decomposition of 31 kcal mol^?1 and a calculated lifetime of 0.9 years. All other compounds studied would readily decompose to lower oxidation states.