Revising the Highest Oxidation States of the 5d Elements: The Case of Iridium(+VII)

The magnificent VII? High‐level quantum chemical calculations show iridium in oxidation state +VII to be a viable synthetic target, whereas higher oxidation states of this element appear unlikely. With the theoretically predicted Ir VII and Hg IV included, a linear descent of maximum oxidation states from Os to Hg is found in the 5d series (see Figure: • highest experimentally known values, ▴ probably incorrect experimental assignments, and □ most likely predicted values).