title: On the Extreme Oxidation States of Iridium.
abstract: It has recently been suggested that the oxidation states of Ir run from the putative -III in the synthesized solid Na3 [Ir(CO)3 ] to the well-documented +IX in the species IrO4 (+) . Furthermore, [Ir(CO)3 ](3-) was identified as an 18-electron species. A closer DFT study now finds support for this picture: The orbitals spanned by the 6s,6p,5d orbitals of the iridium are all occupied. Although some have considerable ligand character, the deviations from 18 e leave the orbital symmetries unchanged. The isoelectronic systems from Os(-IV) to Au(-I) behave similarly, suggesting further possible species. To paraphrase Richard P. Feynmann "there is plenty of room at the bottom".
authors.affiliation: Department of Chemistry, University of Helsinki, P.O.B. 55 (A.I. Virtasen aukio 1), FIN-00014 Helsinki (Finland). Pekka.Pyykko@helsinki.fi.
authors.forename: Pekka
authors.initials: P
authors.lastname: Pyykkö
authors.affiliation: Department of Chemistry, University of Helsinki, P.O.B. 55 (A.I. Virtasen aukio 1), FIN-00014 Helsinki (Finland).|Key Laboratory of Synthetic and Natural Functional Molecule, Chemistry of the Ministry of Education, College of Chemistry and Materials Science Department, Northwest University, 710127 Xi'an (China).
authors.forename: Wen-Hua
authors.initials: WH
authors.lastname: Xu
keywords: IR spectroscopy; ab initio calculations; density functional calculations; iridium; oxidation states