A Dy2 single-molecule magnet with benzoate anions and phenol-O− bridging groups†
Abstract
A Dy2 single-molecule magnet, namely [Dy2(H3L)2(PhCOO)4]·4H2O (1), was obtained from the reaction of Dy(PhCOO)3 with 1,5-bis(2-hydroxy-3-methoxybenzylidene)carbonohydrazide (H4L). Each DyIII ion is located in the chelating pocket [DyO8N] formed by the carboxyl-O, phenol-O, carbohydrazide-O and carbohydrazide-N, forming a tricapped trigonal prism configuration. The DyIII centers are bridged by the benzoate anions with μ2:η1,η2 coordination mode and the phenol-O− groups in the form of μ1:η2, respectively. The appearance of frequency-dependent out-of-phase (χ′′M) signals indicates that 1 displays single-molecule magnet (SMM) behaviour. Fits of the ac data gave an energy barrier (Ueff) of 42.7 K with a pre-exponential factor (τ0) of 1.31 × 10−7 s. The structure–property relationship of some selected Dy2 paradigmatic compounds was further discussed.