Fine Control of the Metal Environment within Dysprosium-Based Mononuclear Single-Molecule Magnets

A new family of three Dy-III mononuclear complexes and one DyIII chain system based on the same ligand [1,3-di(pyridin-4-yl)propane-1,3-dione] has been isolated as single crystals. By varying the synthesis conditions, it has been possible to finely control the number of ligands coordinated to the central lanthanide atom (from 1 to 3) and then the total charge of the complex unit (from +2 to neutral), as well as the local geometry around the Dy-III ion (from D-4d to D-2d). The magnetic properties of the four complexes have been studied and rationalized by ab initio calculations to illustrate the correlation between the metal-ion environment, due to the number of coordinated ligands, and their SMM behaviours.