Extended Fe_4 butterfly complexes: Theoretical analysis of magnetic properties and magnetostructural maps

摘要

The inclusion of additional metal atoms in Fe_4 butterfly complexes drastically modifies their magnetic properties. Exchange interactions of a Fe_4Y_2 complex have been calculated using theoretical methods based on density functional theory. The calculated values are in good agreement with experimental data showing that the change in the nature of bridging ligands induces a dramatic decrease of the antiferromagnetic wing-body interaction while the body-body interaction between the two central iron atoms is ferromagnetic. Finally, we propose a new tool to facilitate the understanding of the magnetic properties in polynuclear iron complexes. Magnetostructural maps allow us to correlate the calculated exchange coupling constants with metal-metal distances for the dinuclear or polynuclear iron complexes that we have studied.