A Local D 4h Symmetric Dysprosium(III) Single-Molecule Magnet with an Energy Barrier Exceeding 2000 K

Three six-coordinate Dy single-molecule magnets (SMMs) [Dy(O Bu) (L) ] with local D symmetry are obtained by optimizing the equatorial ligands. One of the compounds with L=4-phenylpyridine shows an energy barrier (U ) of 2075(11) K, which is the third largest U , and the first U >2000 K for SMMs with axial-type symmetry so far. Ab initio analysis indicates that the exceptional uniaxial magnetic anisotropy is deeply related to the axially compressed octahedral geometry. This work provides a new insight into the local D symmetry for high-performance SMMs.