Iridium tetroxide (IrO4, Iridium(VIII) oxide) is a binary compound of oxygen and iridium in oxidation state +VIII. This compound was formed by photochemical rearrangement of [(η1O2)IrO2] in solid argon at a temperature of 6 K (−267 °C, −449 °F). At higher temperatures the oxide is unstable.
^Gong, Yu; Zhou, Mingfei; Kaupp, Martin; Riedel, Sebastian (2009). "Formation and Characterization of the Iridium Tetroxide Molecule with Iridium in the Oxidation State +VIII". Angewandte Chemie International Edition48 (42): 7879. doi:10.1002/anie.200902733.
^20030138958, Blalock, Guy T., Micron technology, Inc., "Detection of gas phase materials", published 24-07-2003
^Citra, Angelo; Andrew, Lester (1999). "Reactions of Laser-Ablated Iridium Atoms with O2. Infrared Spectra and DFT Calculations for Iridium Dioxide and Peroxo Iridium(VI) Dioxide in Solid Argon". J. Phys. Chem. A103 (21): 4182–4190. doi:10.1021/jp990388o.