title: Strategy for the rational design of asymmetric triply bridged dinuclear 3d-4f single-molecule magnets.
abstract: Three triply bridged M(II)-Dy(III) dinuclear complexes, [Ni(μ-L)(μ-OAc)Dy(NO(3))(2)] 1, [Zn(μ-L)(μ-OAc)Dy(NO(3))(2)] 2, and [Ni(μ-L)(μ-NO(3))Dy(NO(3))(2)]·2CH(3)OH 3 were prepared with a new and flexible compartmental ligand, N,N',N″-trimethyl-N,N″-bis(2-hydroxy-3-methoxy-5-methylbenzyl)diethylene triamine (H(2)L), containing N(3)O(2)-inner and O(4)-outer coordination sites. These complexes have diphenoxo/acetate (1 and 2) or diphenoxo/nitrate (3) asymmetric bridging fragments. Compounds 1 and 3 exhibit ferromagnetic interaction between Ni(2+) and Dy(3+) ions and frequency dependence of the out-of-phase (χ″(M)) alternating current (ac) susceptibility signal characteristic of single-molecule-magnet behavior. The energy barriers Δ/k(B) for compound 3 under zero and 1000 Oe applied direct current (dc) magnetic fields were estimated from the Arrhenius plots to be 7.6 and 19.1 K, respectively.
authors.affiliation: Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, Av. Fuentenueva S/N, 18071 Granada, Spain. ecolacio@ugr.es
authors.forename: Enrique
authors.initials: E
authors.lastname: Colacio
authors.forename: José
authors.initials: J
authors.lastname: Ruiz-Sanchez
authors.forename: Fraser J
authors.initials: FJ
authors.lastname: White
authors.forename: Euan K
authors.initials: EK
authors.lastname: Brechin