On Approaching the Limit of Molecular Magnetic Anisotropy: A Near-Perfect Pentagonal Bipyramidal Dysprosium(III) Single-Molecule Magnet
Graphical Abstract
Record-breaking: A monometallic dysprosium complex, [Dy(OtBu)2(py)5][BPh4], displaying near-perfect pentagonal bipyramid geometry defined by two strong axial tert-butoxide ligands and five weak equatorial pyridine donors is reported. This complex displays massive magnetic anisotropy, approaching the limit of a two-coordinate complex, with an energy barrier to magnetic relaxation of Ueff=1815(1) K and a blocking temperature of TB=14 K.
Abstract
We report a monometallic dysprosium complex, [Dy(OtBu)2(py)5][BPh4] (5), that shows the largest effective energy barrier to magnetic relaxation of Ueff=1815(1) K. The massive magnetic anisotropy is due to bis-trans-disposed tert-butoxide ligands with weak equatorial pyridine donors, approaching proposed schemes for high-temperature single-molecule magnets (SMMs). The blocking temperature, TB , is 14 K, defined by zero-field-cooled magnetization experiments, and is the largest for any monometallic complex and equal with the current record for [Tb2N2{N(SiMe3)2}4(THF)2].
