Correlation between magnetism and luminescence in redox active single molecule magnets
Résumé
Lanthanide ions are well-known to exhibit large magnetic moments and strong magnetic anisotropy and therefore they are considered as good candidates for the elaboration of Single Mol. Magnets (SMMs). Complexation of these particular metal ions by redox active ligands derived from TTFs led to electroactive SMM with antennae effect of the ligands as well as very good correlation between magnetism and luminescence at the mol. scale. We report in this lecture several compds. exemplifying these features.Among them, dinuclear complexes of lanthanides assocg. both 4,5-Bis(thiomethyl) -4'-carboxylictetrathiafulvalene and 4,5-Bis(thiomethyl) -4'-ortho-pyridyl -N-oxide -carbamoytetrathiafulvalene ligands have been elaborated. Dc magnetic susceptibility measurements highlight ferromagnetic interactions between the metallic centers. The two Dy(III) and Yb(III)-based analogs display SMM behavior. Exptl. and theor. magnetic and photo-phys. investigations have confirmed that a multi-electroactive luminescent SMM is obtained in the case of the Yb(III) analog.