title: Heterometallic Fe2 (II) -U(V) and Ni2 (II) -U(V) Exchange-Coupled Single-Molecule Magnets: Effect of the 3 d Ion on the Magnetic Properties.
abstract: Uranium-based compounds have been put forward as ideal candidates for the design of single-molecule magnets (SMMs) with improved properties, but to date, only two examples of exchange-coupled 3d-5f SMM containing uranium have been reported and both are based on the Mn(II) ion. Here we have synthesized the first examples of exchange-coupled uranium SMMs based on Fe(II) and Ni(II) . The SMM behavior of these complexes containing a quasi linear {M-O=U=O-M} core arises from intramolecular Fe-U and Ni-U exchange interactions combined with the high Ising anisotropy of the uranyl(V) moiety. The measured values of the relaxation barrier (53.9±0.9 K in the UFe2 complex and of 27.4±0.5 K in the UNi2 complex) show clearly the dependency on the spin value of the transition metal, providing important new information for the future design of improved uranium-based SMMs.
authors.affiliation: Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne (Switzerland).|Université Grenoble Alpes, INAC-SCIB, 38000 Grenoble (France).|CEA, INAC-SCIB, 38000 Grenoble (France).
authors.forename: Lucile
authors.initials: L
authors.lastname: Chatelain
authors.affiliation: Université Grenoble Alpes, INAC-SCIB, 38000 Grenoble (France).|CEA, INAC-SCIB, 38000 Grenoble (France).
authors.forename: Jacques
authors.initials: J
authors.lastname: Pécaut
authors.affiliation: School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester, M13 9PL (UK).
authors.forename: Floriana
authors.initials: F
authors.lastname: Tuna
authors.affiliation: Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne (Switzerland). marinella.mazzanti@epfl.ch.
authors.forename: Marinella
authors.initials: M
authors.lastname: Mazzanti
keywords: actinides; cations; magnetic properties; polymetallic complexes; single-molecule magnets; uranium