A Single-Molecule Magnet with an Enhanced Magnetization Reversal Barrier through Fine-Tuning of the Ligand Environment

was synthesized and characterized by single-crystal X-ray diffraction (Fig. 1a). Although 2 exhibits a pentagonal bipyramidal geometry like that in 1, there are pronounced structural changes such as a sizable deviation of the donor atoms from planarity in the equatorial region and a larger O1−Dy−O2 angle. Ab initio calculations revealed significantly higher energies for the excited sublevels of the ground state compared to 1 (Fig. 1b). The calculated g-tensor indicates high axiality up to the third excited substate, whereas for 1, axiality is maintained only up to the second excited sublevel. Consequently, the effective energy barrier for magnetization reversal, U_eff, was predicted to lie between 631 and 755 cm^-1, a value significantly higher than in 1 (495 cm^-1, Fig. 1c). DC and AC magnetic measurements are underway to confirm the promising SMM behavior of 2.