Molecular Assembly and Magnetic Dynamics of Two Novel Dy6 and Dy8 Aggregates

Complexation of dysprosium­(III) with the heterodonor chelating ligand o-vanillin picolinoylhydrazone (H2ovph) in the presence of a carbonato ligand affords two novel Dy6 and Dy8 clusters, namely, [Dy6(ovph)4(Hpvph)2Cl4(H2O)2(CO3)2]·CH3OH·H2O·CH3CN (2) and [Dy8(ovph)8(CO3)4(H2O)8]·12CH3CN·6H2O (3). Compound 2 is composed of three petals of the Dy2 units linked by two carbonato ligands, forming a triangular prism arrangement, while compound 3 possesses an octanuclear core with an unprecedented tub conformation, in which Dy­(ovph) fragments are attached to the sides of the carbonato core. The static and dynamic magnetic properties are reported and discussed. In the Dy6 aggregate, three Dy2 “skeletons”, having been well preserved (see the scheme), contribute to the single-molecule-magnet behavior with a relatively slow tunneling rate, while the Dy8 cluster only exhibits a rather small relaxation barrier.