A single-molecule magnet featuring a parallelogram [Dy-4(OCH2-)(4)] core and two magnetic relaxation processes

An alkoxido-bridged tetranuclear Dy(III) complex, [Dy-4(H3L)(2)(OAc)(6)]center dot 2EtOH {1, H6L = 1,3-bis[tris(hydroxymethyl) methylamino] propane}, has been solvothermally synthesized and characterized. An X-ray crystallographic study revealed that complex 1 possesses a novel parallelogram [Dy-4(OCH2-)(4)] core, and a new binding mode eta(3):eta(3):eta(1):eta(1):eta(1):eta(2):mu(4) of the Bis-tris propane ligand was observed. Magnetic investigations indicated that it is a single-molecule magnet (SMM), showing two distinct magnetic relaxation processes with the energy barriers of 44 K and 107 K, respectively. Such a two-step magnetic relaxation process could be well described by the sum of two modified Debye functions.