Oxidation State 10 Exists.

In a recent paper, Wang et al. found an iridium-containing compound with a formal oxidation state of 9. 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. [ABSTRACT FROM AUTHOR]