On the Upper Limits of Oxidation States in Chemistry

Shu-Xian Hu; Wan-Lu Li; Jun-Bo Lu; Junwei Lucas Bao; Haoyu S Yu; Donald G Truhlar; John K Gibson; Joaquim Marçalo; Mingfei Zhou; Sebastian Riedel; W H Eugen Schwarz; Jun Li

doi:10.1002/anie.201711450

On the Upper Limits of Oxidation States in Chemistry

Angew Chem Int Ed Engl. 2018 Mar 12;57(12):3242-3245. doi: 10.1002/anie.201711450. Epub 2018 Feb 19.

Authors

Shu-Xian Hu^{1

2}, Wan-Lu Li¹, Jun-Bo Lu¹, Junwei Lucas Bao³, Haoyu S Yu³, Donald G Truhlar³, John K Gibson⁴, Joaquim Marçalo⁵, Mingfei Zhou⁶, Sebastian Riedel⁷, W H Eugen Schwarz^{1

8}, Jun Li¹

Affiliations

¹ Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, China.
² Beijing Computer Science Research Center, Haidian, Beijing, 100193, China.
³ Chemical Theory Center, Department of Chemistry, and Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, MN, 55455-0431, USA.
⁴ Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
⁵ Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, 2695-066, Bobadela LRS, Portugal.
⁶ Department of Chemistry, Fudan University, Shanghai, 200433, China.
⁷ Anorganische Chemie, Institut für Chemie und Biochemie, Freie Universität Berlin, 14195, Berlin, Germany.
⁸ Physical and Theoretical Chemistry Lab, Universität Siegen, 57068, Siegen, Germany.

PMID: 29314484
DOI: 10.1002/anie.201711450

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 highest OS in stable neutral chemical substances under ambient conditions. OS=+9 was observed for the isolated [IrO₄ ]⁺ cation in vacuum. The prediction of OS=+10 for isolated [PtO₄ ]²⁺ cations is confirmed computationally for low temperatures only, but hasn't yet been experimentally verified. For high OS 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.

Keywords: bonding theory; computational chemistry; oxidation states; oxides; transition metals.

Publication types

Research Support, Non-U.S. Gov't