Structures and magnetic properties of two series of Ln 2 complexes: Tb 2 complexes showing distinct slow magnetic relaxation

Two series of new lanthanide dinuclear complexes having formulae, [Ln2(hfac)4(L1)2] (Ln = Tb (1), Er (2) and Lu (3), hfac = hexafluoroacetylacetone and HL1 = 2-[4-methylaniline-imino]methyl]-8-hydroxyquinoline) and [Ln2(hfac)4(L2)2] (Ln = Tb (4), Ho (5) and Er (6), hfac = hexafluoroacetylacetone and HL2 = 2-[(3,4-dimethylaniline)-imino]methyl]-8-hydroxyquinoline), have been successfully synthesized and studied interms of their magnetic properties. Magnetic studies reveal that 1 and 4 shows distinct slow magnetic relaxation. Indeed, no out-of-phase alternating current (ac) signal is noticed for 1, whereas 4 shows a slow relaxation of magnetization with energy barriers (ΔE/kB) of 6.84 K while application of an external dc field (2000 Oe).