Two Lanthanide–nitronyl nitroxide radicals compounds with slow magnetic relaxation behavior

Two Lanthanide compounds with nitronyl nitroxide radicals [Dy(hfac)3(NITPh-p-Cl)2·0.5CH3(CH2)5CH3] (1) (hfac = hexafluoroacetylacetonate; NITPh-p-Cl = 4′-chlorphenyl-4,4,5,5-tetramethylimida-zoline-1-oxyl-3-oxide, CH3(CH2)5CH3 is heptane as solvent molecule) and [Tb(hfac)3(NITPh-p-Cl)2] (2) were synthesized and structurally characterized. The X-ray crystallographic analyses show that the structures of the two compounds are similar and all consist of isolated molecules, in which central Ln(III) ions are coordinated to six oxygen atoms from three hexafluoroacetylacetonate ligands and two oxygen atoms from nitronyl nitroxide radicals. Ac magnetic susceptibility studies show complexes 1 and 2 exhibit slow magnetic relaxation, suggesting single-molecule magnet behavior.