Magnetic interactions in Cu-containing heterospin polymer

TL;DR

This study uses first-principles density functional theory to analyze the magnetic interactions in a Cu-based heterospin polymer, revealing predominantly antiferromagnetic coupling between Cu(II) ions and organic radicals.

Contribution

It provides the first detailed electronic structure analysis of Cu hexafluoroacetylacetonate with nitronyl nitroxide radicals, highlighting the magnetic interaction nature and magnitude.

Findings

Predominantly antiferromagnetic interaction with a magnitude of 67 cm^{-1}

Electronic structure analysis explains magnetic coupling preferences

First-principles calculations validate experimental magnetic behavior

Abstract

The electronic structure of Cu hexafluoroacetylacetonate, crystallized with a stable nitronyl nitroxide radical [Ovcharenko et al., Russ. Chem. Bull. 53, 2406 (2004)], is calculated from first principles within the density functional theory using the SIESTA method, in two magnetic configurations reflecting parallel or antiparallel setting of S=1/2 spins of Cu(II) ions to those of organic radicals. For a given (high-temperature) crystal structure, the interaction is found to be predominanty antiferromagnetic, and its magnitude estimated to be 67 inv.cm. This preference is discussed in terms of calculated electronic properties (densities of states, molecular orbitals).