title: New families of hetero-tri-spin 2p-3d-4f complexes: synthesis, crystal structures, and magnetic properties.
abstract: In this work we report the synthesis, crystal structures, and magnetic behavior of 2p-3d-4f heterospin systems containing the nitroxide radical 4-azido-2,2,6,6-tetramethylpiperidine-1-oxyl radical (N3tempo). These compounds were synthesized through a one-pot reaction by using [Cu(hfac)2], [Ln(hfac)3] (hfac = hexafluoroacetylacetonate, Ln = Dy(III), Tb(III) or Gd(III)), and the N3tempo radical. Depending on the stoichiometric ratio used, the synthesis leads to penta- or trimetallic compounds, with molecular formulas [Cu3Ln2(hfac)8(OH)4(N3tempo)] (Ln = Gd, Tb, Dy) and [CuLn2(hfac)8(N3tempo)2(H2O)2] (Ln = Gd, Dy). The magnetic properties of all compounds were investigated by direct current (dc) and alternating current (ac) measurements. The ac magnetic susceptibility measurements of Tb(III)- and Dy(III)-containing compounds of both families revealed slow relaxation of the magnetization, with magnetic quantum tunneling in zero field.
authors: Instituto de Química and ‡Instituto de Física, Universidade Federal Fluminense , Niterói, Rio de Janeiro, Brazil.
authors: Lívia B L
authors: LB
authors: Escobar
authors: Guilherme P
authors: GP
authors: Guedes
authors: Stéphane
authors: S
authors: Soriano
authors: Nivaldo L
authors: NL
authors: Speziali
authors: Alessandro K
authors: AK
authors: Jordão
authors: Anna Claudia
authors: AC
authors: Cunha
authors: Vitor F
authors: VF
authors: Ferreira
authors: Catalin
authors: C
authors: Maxim
authors: Miguel A
authors: MA
authors: Novak
authors: Marius
authors: M
authors: Andruh
authors: Maria G F
authors: MG
authors: Vaz