Zinc in a +III oxidation state

TL;DR

This paper uses density functional theory to demonstrate that zinc can exist in a +III oxidation state when stabilized by ligands with high electron affinities, challenging traditional oxidation state expectations.

Contribution

The study shows that zinc can attain a +III oxidation state through specific ligand interactions, expanding the understanding of zinc's chemical versatility.

Findings

Zinc can achieve a +III oxidation state with high electron affinity ligands.

Ligands with increasing electron affinities stabilize higher oxidation states.

This finding opens new possibilities for zinc chemistry and reactions.

Abstract

The possibility of Group 12 elements, such as Zn, Cd, and Hg existing in an oxidation state of +III or higher and hence transforming them into transition metals has fascinated chemists for decades. It took nearly 20 years before experiment could confirm the theoretical prediction that Hg indeed can exist in an oxidation state of +IV. While this unusual property of Hg is attributed to the relativistic effects, Zn being much lighter than Hg has not been expected to have an oxidation state higher than +II. Using density functional theory we show that an oxidation state of +III for Zn can be realized by choosing specific ligands with large electron affinities. We demonstrate this by a systematic study of the interaction of Zn with F, BO2, and AuF6 ligands whose electron affinities are progressively higher, namely, 3.4 eV, 4.5 eV, and 8.6 eV, respectively. Discovery of higher oxidation states of elements can help in the formulation of new reactions and hence in the development of new chemistry.