Inside Cover: Formation and Characterization of the Iridium Tetroxide Molecule with Iridium in the Oxidation State +VIII (Angew. Chem. Int. Ed. 42/2009)

Although +VI has long been the highest experimentally known oxidation state of Ir, the +VIII oxidation state has been produced and identified in low-temperature noble gas matrices of iridium tetroxide. M. F. Zhou, S. Riedel, and co-workers describe in their Communication on page 7879 ff. how the compound is formed by co-depositing Ir atoms with mixtures of O2 and a noble gas onto a CsI surface at 4–6 K. Theoretical analysis indicates that it is a d1 species with the formal oxidation state IrVIII.