Two novel tetranuclear lanthanide complexes (Ln = Tb(III) and Dy(III)) with luminescence and slow magnetic relaxation behaviors

Abstract

Two novel tetranuclear lanthanide complexes, [Ln4(μ3-OH)2L6(tmhd)4] (Ln = Tb (1) and Dy (2)), were successfully synthesized by using 5-(2-hydroxylbenzylidene)-8-hydroxylquinoline (HL) and 2,2,6,6-tetramethyl-3,5-heptanedione (Htmbd). The investigation of single-crystal X-ray diffraction showed that the structures of 1 and 2 are both composed of butterfly-shaped [Ln4O2] clusters in the center, and of which four Ln(III) ions are all eight-coordinated. Moreover, the luminescence test reveal that 1 exhibits four characteristic peaks of Tb(III); while for 2, it is magnetically characterized and alternating-current (ac) magnetic susceptibility suggests slow magnetic relaxation behavior was occurred in 2 with the energy barrier (ΔE/kB) of 81.76 K.