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

Abstract Two novel tetranuclear lanthanide complexes, [Ln 4 (μ 3 -OH) 2 L 6 (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 [Ln 4 O 2 ] 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 (Δ E / k B ) of 81.76 K.