Magnetic properties of a europium(iii) complex – possible multiplet crossover†
Abstract
A dinuclear complex [(H2O)Zn(LH)Eu(NO3)3] containing a hexadentate Schiff-base {N2O4}-donor ligand LH2− was prepared and characterized by X-ray structural analysis and IR, electronic and fluorescence spectroscopy. DC magnetic data show that upon heating the diamagnetic complex with the ground state Eu(III)–7F0 and Zn(II)–1S switches to paramagnetic species due to the population of 7FJ (J = 1 to 6) magnetic multiplets. The magnetic susceptibility increases from zero, passes through a maximum, and then decreases upon heating. This behaviour can be explained using a spin–orbit Hamiltonian with an axial distortion term. There is an alternative interpretation of the susceptibility data based on a two-level model similar to that used in the spin crossover theory.