ERROR 1
ERROR 1
ERROR 2
ERROR 2
ERROR 2
ERROR 2
ERROR 2
Password and Confirm password must match.
If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)
ERROR 2
ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.
Despite theoretical predictions that iridium is limited to a maximum oxidation state of 7+, a group led by Mingfei Zhou of Fudan University, in Shanghai, and Sebastian Riedel of Albert Ludwigs University, in Freiburg, Germany, has experimentally observed IrO4 featuring an 8+ iridium center (Angew. Chem. Int. Ed., DOI: 10.1002/anie.200902733). The researchers formed the compound by codepositing iridium with O2 and a noble gas onto a CsI surface at 4 to 6 K. After annealing the sample to 30 K, they used infrared spectroscopy to detect (η1-O2)IrO2, where (η1-O2) represents the end-on arrangement O–O–IrO2. Irradiating the sample with infrared light produced (η2-O2)IrO2, where η2-O2 indicates a side-on bound O2 (forming a three-membered IrO2 ring). Further irradiation with visible light produced the complex identified as IrO4, which has four terminal Ir=O bonds. Computational analysis indicates that the latter compound is a d1 species with the formal iridium oxidation state of 8+. That the molecule can exist, at least at low temperature, is likely due to the comparably low steric repulsions of the four divalent oxo ligands combined with the relatively large electronegativity of oxygen, the researchers say.
Join the conversation
Contact the reporter
Submit a Letter to the Editor for publication
Engage with us on Twitter