A dinuclear dysprosium Schiff base complex showing slow magnetic relaxation in the absence of an external magnetic field

Abstract

A dinuclear dysprosium(III) complex [Dy₂(NO₃)₃(L)₃]·nCH₃OH (n = 1.20; HL = (2-[(2-hydroxy-propylimino)methyl]phenol)) (1) was isolated when dysprosium nitrate reacted with a solution of salicylaldehyde and 1-amino-2-propanol in a basic medium under in-situ reaction conditions. The isolated complex was characterized by single crystal X-ray diffraction studies at room temperature. The complex is built up of a dinuclear {Dy₂} molecule in which the two Dy(III) central atoms are triply linked by O-monoatomic bridges arising from deprotonated hydroxyl groups of the three L ligands; these act as doubly chelating & bridging ligands. Both Dy(III) atoms exhibit nona-coordination with donor sets O₈N and O₇N₂, respectively. The coordination spheres of the respective Dy(III) atoms are completed by one or two chelating nitrato ligands. The magnetic properties of 1 have been investigated by DC and AC susceptibility measurements. The DC measurements reveal a slight exchange coupling of an antiferromagnetic nature. The out-of-phase AC susceptibility signal is seen even at zero applied field. The low-frequency relaxation mode is supported by an external magnetic field.