On the Upper Limits of Oxidation States in Chemistry. Issue 12 (19th February 2018)

• Record Type: Journal Article
• Authors: Hu, Shu‐Xian; Li, Wan‐Lu; Lu, Jun‐Bo; Bao, Junwei Lucas; Yu, Haoyu S.; Truhlar, Donald G.; Gibson, John K.; Marçalo, Joaquim; Zhou, Mingfei; Riedel, Sebastian; Schwarz, W. H. Eugen; Li, Jun
• Is Part Of: Angewandte Chemie international edition. Volume 57:Issue 12(2018)
• Page Start: 3242
• Page End: 3245
• Publication Date: 2018-02-19
• Subjects: bonding theory -- computational chemistry -- oxidation states -- oxides -- transition metals; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201711450
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The concept of oxidation state (OS ) is based on the concept of Lewis electron pairs, in which the bonding electrons are assigned to the more electronegative element. This approach is useful for keeping track of the electrons, predicting chemical trends, and guiding syntheses. Experimental and quantum‐chemical results reveal a limit near +8 for the highestOS in stable neutral chemical substances under ambient conditions.OS =+9 was observed for the isolated [IrO4 ] + cation in vacuum. The prediction ofOS =+10 for isolated [PtO4 ] 2+ cations is confirmed computationally for low temperatures only, but hasn't yet been experimentally verified. For highOS species, oxidation of the ligands, for example, of O −2 with formation of . O −1 and O−O bonds, and partial reduction of the metal center may be favorable, possibly leading to non‐Lewis type structures. Abstract : The highest oxidation state ( OS ) of elements in compounds is limited not only by the number and the ionization energies of their valence electrons, but also by the electronic properties of the ligands. Spontaneous oxidation of the ligand and reduction of the metal center results in strongly correlated, open‐shell, multicenter bonds. A joint theoretical–experimental case study of PtO4 2+ isomers reveals a maximum OS near +8 for chemical substances under ambient conditions.