Self-Assembly Heterometallic Cu-Ln Complexes: Synthesis, Crystal Structures and Magnetic Characterization

Abstract

Using N2O4 donor symmetric ligand H2L and dca co-ligand, two new isostructural dinuclear CuII–LnIII complexes [Cu(Cl)(L)Ln(NO3)(CH3OH)(H2O)(dca)] [Ln=Ho (1CuHo), Gd (2CuGd)] [H2L = 6,6′-((1E,1′E)-(ethane-1,2-diylbis(azaneylylidene))bis(methaneylylidene))bis(2-methoxyphenol); dca=dicyanamide] were designed, synthesized and studied. In the two isostructural compounds, the geometric environment around the nine-coordinated Ln(III) ions is muffin, whereas the geometry of the penta-coordinated Cu(II) ions is square pyramid. The magnetic properties of both complexes were also studied. Direct current magnetic susceptibility measurements indicate ferromagnetic interactions between the Cu(II) ion and Gd(III) ion in complex 2CuGd. Alternating current (ac) magnetic measurements indicate that complex 1CuHo displays slow magnetic relaxation behaviour.