Quantification of the Magnetic Anisotropy of a Single-Molecule Magnet from the Experimental Electron Density.
Reported here is an entirely new application of experimental electron density (EED) in the study of magnetic anisotropy of single-molecule magnets (SMMs). Among those SMMs based on one single transition metal, tetrahedral CoII-complexes are prominent, and their large zero-field splitting arises exclusively from coupling between the d  and dxy orbitals. Using very low temperature single-crystal synchrotron X-ray diffraction data, an accurate electron density (ED) was obtained for a prototypical SMM, and the experimental d-orbital populations were used to quantify the dxy-d  coupling, which simultaneously provides the composition of the ground-state Kramers doublet wave function. Based on this experimentally determined wave function, an energy barrier for magnetic relaxation in the range 193-268 cm-1 was calculated, and is in full accordance with the previously published value of 230 cm-1 obtained from near-infrared spectroscopy. These results provide the first clear and direct link between ED and molecular magnetic properties.
['Damgaard-Møller|Emil|E|http://orcid.org/0000-0002-8280-0946', 'Krause|Lennard|L|', 'Tolborg|Kasper|K|', 'Macetti|Giovanni|G|http://orcid.org/0000-0001-9935-7955', 'Genoni|Alessandro|A|http://orcid.org/0000-0002-3511-4855', 'Overgaard|Jacob|J|http://orcid.org/0000-0001-6492-7962']
electron density X-ray diffraction magnetic properties cobalt single-molecule studies