A state of eight: Iridium atoms insert into dioxygen to form iridium dioxide molecules in solid noble-gas matrixes. Annealing allows formation of the iridium dioxide superoxide complex [(¹-O₂)IrO₂], which isomerizes under IR irradiation to the iridium dioxide peroxide complex [(²-O₂)IrO₂]. These complexes photochemically rearrange to the more stable iridium tetroxide molecule with an iridium oxidation state of +VIII.

Publication in Angew. Chem.

C&EN reports about Iridium VIII as IrO₄

Ir^VIII wieder im Rennen

New Species / High Oxidation States

Mercury Tetrafluoride Synthesized

Our calculations indicate clearly that the species claimed to be AuF₇ had not been synthesized. Instead, a new gold fluoride complex AuF₅·F₂ was prepared.