Magnetic Properties of Dysprosium Cubanes Dictated by the M-O-M Angles of the [Dy4(μ3-OH)4] Core

Two new dysprosium(III) coordination compounds, namely, [Dy-4(HL)(4)(C6H4NH2COO)(2)(mu(3)-OH)(4)(u-OH)(2)(H2O)(4)]center dot 4CH(3)CN center dot 12H(2)O (1) and Dy-8(HL)(10)(C6H4NH2COO)(2)(mu(3)-OH)(8)(OH)(2)(NO3)(2)(H2O)(4)] (2), have been synthesized from the Schiff-base ligand 2-{[(2-hydroxy-3-methoxyphenyl)methylidene]aminolbenzoic acid (H2L) and dysprosium chloride (1) or dysprosium nitrate (2). Single-crystal X-ray diffraction studies reveal that compound 1 exhibits a tetranuclear cubane-like structure and that 2 is an octanuclear, bis-cubane complex. The [Dy-4(mu(3)-OH)(4)] cubane cores of 1 and 2 are structurally related; however, the magnetic properties of 1 and 2 are drastically different. Indeed, 2 shows slow relaxation of magnetization while no out-of-phase alternating current (ac) signal is noticed for 1. These significant disparities are most likely due to the different M-O-M angles observed for the respective cubane cores.