High-Coordinated Dy2 Single-Molecule Magnet with an Anistropy Barrier Exceeding 700 K

We report the synthesis and characterization of a symmetric dinucler DyIII complex (1) based on the use of bulk pentapyridyldiamine (BPA-TPA) and bridging hydroquinone ligands. Each DyIII ion is wrapped by a BPA-TPA ligand, leaving only one site to bond one O donor atom from the hydroquinone, which generates a triangular dodecahedral coordinate geometry. Magnetic measurements reveal that complex 1 exhibits a high anistropy barrier of 727(4) K and the temperature of hysteresis loops up to 20 K with remanence at the zero field. However, the Y(III)-diluted analogue 1@Y shows that butterfly-shaped hysteresis loops are closed at the zero field. This discrepancy clearly demonstrates the positive effect of axial magnetic interaction between the DyIII dimer. The fascinating behavior is ascribed to the pseudolinear ligand field with an exceptionally short Dy–O bond, as confirmed by theoretical calculations.