Ag(II) as spin super-polarizer in metal fluoride clusters

TL;DR

This study uses quantum calculations to show that Ag(II) can significantly alter magnetic interactions in fluoride-bridged clusters, acting as a spin superpolarizer with potential applications in spintronics.

Contribution

It provides the first theoretical evidence that Ag(II) can dramatically modify magnetic coupling in molecular clusters, including switching from antiferro- to ferromagnetic interactions.

Findings

Ag(II) can change the sign and strength of magnetic coupling.

Presence of Ag(II) increases superexchange by up to 17 times.

Ag(II) acts as a spin superpolarizer in molecular systems.

Abstract

Using quantum mechanical calculations, we examine magnetic (super)exchange interactions in hypothetical, chemically reasonable molecular coordination clusters containing fluoride bridged late transition metals or selected lanthanides, as well as Ag(II). By referencing to analogous species comprising closed shell Cd(II) we provide theoretical evidence that the presence of Ag(II) may modify the magnetic properties of such systems (including metal metal superexchange) to a surprising degree, specifically both coupling sign and strength may markedly change. Remarkably, this happens in spite of the fact that the fluoride ligand is the least susceptible to spin polarization among all monoatomic ligands known in chemistry. In an extreme case of a oxo bridged Ni(II)2 complex, the presence of Ag(II) leads to a nearly 17 fold increase of magnetic superexchange and switching from antiferro- to ferromagnetic coupling. Ag(II), with one hole in its d shell that may be shared with or transferred to ligands, effectively acts as spin superpolarizer, and this feature could be exploited in spintronics and diverse molecular devices.