Mononuclear Single-Molecule Magnets: Tailoring the Magnetic Anisotropy of First-Row Transition-Metal Complexes

Magnetic anisotropy is the property
that confers to the spin a
preferred direction that could be not aligned with an external magnetic
field. Molecules that exhibit a high degree of magnetic anisotropy
can behave as individual nanomagnets in the absence of a magnetic
field, due to their predisposition to maintain their inherent spin
direction. Until now, it has proved very hard to predict magnetic
anisotropy, and as a consequence, most synthetic work has been based
on serendipitous processes in the search for large magnetic anisotropy
systems. The present work shows how the property can be predicted
based on the coordination numbers and electronic structures of paramagnetic
centers. Using these indicators, two CoII complexes known
from literature have been magnetically characterized and confirm the
predicted single-molecule magnet behavior.