Slow relaxation of magnetization in a {Fe6Dy} complex deriving from a family of highly symmetric metallacryptands

The synthesis and characterization of a new family of isostructural {Fe(6)Ln} complexes, (pipH)(3){Fe(6)Ln(shiH)(3)(shi)(6)}1.5 pipxH(2)O (Ln = Gd (1), Dy (2), Tb (3) and Y (4), pip = piperidine, and shi(3-) = salicylhydroxamic acid) is reported. The resulting compounds possess an exceptionally unique structure of a metallacrown-like motif while the overall complexes feature more the structure of metallacryptates. Magnetic studies are reported and reveal that the {Fe6Dy} analogue belongs to the single-molecule magnet (SMM) family.