Oxidation states and ionicity
Open Access
- 1 October 2018
- journal article
- research article
- Published by Springer Nature in Nature Materials
- Vol. 17 (11), 958-964
- https://doi.org/10.1038/s41563-018-0165-7
Abstract
The concepts of oxidation state and atomic charge are entangled in modern materials science. We distinguish between these quantities and consider their fundamental limitations and utility for understanding material properties. We discuss the nature of bonding between atoms and the techniques that have been developed for partitioning electron density. While formal oxidation states help us count electrons (in ions, bonds, lone pairs), variously defined atomic charges are usefully employed in the description of physical processes including dielectric response and electronic spectroscopies. Such partial charges are introduced as quantitative measures in simple mechanistic models of a more complex reality, and therefore may not be comparable or transferable. In contrast, oxidation states are defined to be universal, with deviations constituting exciting challenges as evidenced in mixed-valence compounds, electrides and highly correlated systems. This Perspective covers how these concepts have evolved in recent years, our current understanding and their significance.This publication has 53 references indexed in Scilit:
- Electron Counting in Solids: Oxidation States, Partial Charges, and IonicityThe Journal of Physical Chemistry Letters, 2017
- On the Charge State of Titanium in Titanium DioxideThe Journal of Physical Chemistry Letters, 2017
- Oxidation State, A Long‐Standing Issue!Angewandte Chemie International Edition, 2015
- oxidation statePublished by International Union of Pure and Applied Chemistry (IUPAC) ,2014
- A Piece of the Picture—Misunderstanding of Chemical ConceptsAngewandte Chemie International Edition, 2008
- Charge self-regulation upon changing the oxidation state of transition metals in insulatorsNature, 2008
- Ionicity in solidsJournal of Physics C: Solid State Physics, 1983
- ‘Effective’ Ionic Charge in CrystalsNature, 1961
- Ionic-Covalent Bonding in CrystalsNature, 1960
- The modern theory of valencyJournal of the Chemical Society, 1948