Title
Frequency domain magnetic resonance and magnetic circular dichroism studies on Ni4 cubane molecular nanomagnets: A magnetic anisotropy investigation
Author
F. Moro, F. Piga, I. Krivokapic, A. Burgess, W. Lewis, J. McMaster, J. van Slageren
Year
2010
Journal
Inorganica Chimica Acta
Abstract
A study of the magnetic anisotropies of three Ni cubane single-molecule magnets (SMM), [Ni(hmp)(MeOH)Cl]4·H2O (1·H2O) (hmpH = (2-hydroxymethyl)pyridine) [Ni(hmp)(dmb)Cl]4 (2) (dmb = 3,3-dimethylbutanol) and [Ni(hmp)(dmp)Cl]4 (3) (dmp = 2,2-dimethylpropanol) is reported. Frequency domain magnetic resonance spectroscopic (FDMRS) studies on 1, 2 and 3 as powder pellets reveal zero-field splitting (ZFS) for the spin ground states of these compounds in the solid state. The ZFS of the complexes 1 and 2 were determined and the presence of different molecular species was found in both complexes while only one species was found in 3. The nesting of the variable temperature variable field (VTVH) curves observed from magnetic circular dichroism (MCD) measurements on 1 in solution confirms the presence of ZFS. Virtually all the bands observed in the magnetic circular dichroism spectra possess the same sign, which may be related to the ferromagnetic exchange coupling. In addition, MCD measurements of a dilute solution demonstrate the molecular origin of the magnetic anisotropy in 1.
Instrument
J-810
Keywords
Magnetic circular dichroism, Inorganic chemistry,