Subcomponent Self-Assembly of Rare-Earth Single-Molecule Magnets

A family
of lanthanide complexes has been synthesized
by the subcomponent self-assembly methodology. Molecular architectures,
which were stable in solution and under ambient conditions, were designed
by the in situ formation of ligands around lanthanide ion templates.
Magnetic studies indicated that, despite the low C2 symmetry, 1 and 2 display
single molecule magnet (SMM) behavior, with 1 exhibiting
an effective energy barrier of the relaxation of the magnetization Ueff/kB = 50 K and
the pre-exponential factor τo = 6.80 × 10–7 s. Step-like features in the hysteresis loops indicate
the presence of quantum tunneling of the magnetization (QTM).