No abstract

Ab initio and DFT calculations reveal a very strong ferromagnetic exchange of the order of 200 cm(-1) in an endohedral radical hetero-metallo-fullerene molecule Gd2@C79N. Calculations performed on the anisotropic Dy2@C79N molecule reveal that very strong Dy-radical exchange not only quenches the QTM effects but also immensely enhances the barrier height for magnetization reversal.

Two new air-stable axial Dy(iii) single-ion magnets, [Dy(H2O)5(HMPA)2]Cl3·HMPA·H2O (1) and [Dy(H2O)5(HMPA)2]I3·2HMPA (2) (HMPA = hexamethylphosphoramide), exhibit magnetic hysteresis which remains open up to 9 K for 1@Y and 10 K for 2@Y, respectively. Ab initio calculations, using step-by-step elimination of fragments to generate a series of model complexes, reveal that the secondary coordination sphere plays a key role in controlling the magnetisation reversal barrier and predict that the removal of outer-sphere molecules and anions will enhance the barrier further.

A combined synthetic, structural, magnetic and computational study gives insight into improving the single-molecule magnet behaviour of stable high-coordinate Dy(iii) complexes.

Ab initio calculations performed on a series of lanthanide encapsulated fullerenes reveal {DyOSc}@C to be one of the best host-guest pairs to offer a barrier height exceeding 1400 cm. The high-symmetry environment preserved inside the cage quenches the QTM effects up to third-excited states leading to very larger barrier heights and this opens up a new possibility of obtaining attractive SMMs based on lanthanide based endohedral metallo-fullerenes (EMFs).