A new D2d-symmetry DyIII mononuclear single-molecule magnet containing a monodentate N-heterocyclic donor ligand

Abstract

Three new lanthanide complexes [Ln(hfac)₃(pz)₂] (Ln = Dy (1), Tb (2), Ho (3); hfac = hexafluoroacetylacetonate; pz = pyrazole) based on pyrazole have been prepared and characterized structurally. X-ray crystallographic analysis reveals that all three complexes are isomorphous. The crystal structures of these complexes consist of a mononuclear molecule unit in which the center Ln^III ion is surrounded with a slightly distorted D_2d-dodecahedron LnO₆N₂ coordination sphere from three hfac anions and two pyrazole ligands. Both static and dynamic magnetic properties were studied for complex 1, which is proved to be a rarely reported D_2d-symmetry Dy^III mononuclear single-molecule magnet containing a monodentate N-heterocyclic donor ligand, and the luminescence characterization of complexes 1–3 in both visible and NIR regions is also studied.