Five new tri-spin lanthanide-nitronyl nitroxide (Ln ~(III) = Gd ~(III), Tb ~(III), Dy ~(III), Ho ~(III), Er ~(III) complexes: Structures and magnetic properties

摘要

Five radical-Ln(III)-radical complexes, [Ln(hfac) _3(NITPhOC _4H _9) _2] (Ln = Gd (1), Tb (2), Dy (3), Ho (4), Er (5); hfac = hexafluoroacetylacetonate; and NITPhOC _4H _9 = 4′-butoxy-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) have been synthesized, structurally and magnetically characterized. The X-ray crystal structure analysis reveals that the structures of the five complexes are isomorphous in which central Ln(III) ions are coordinated by six oxygen atoms from three hfac and two oxygen atoms from nitronyl radicals. The magnetic studies show that in the Gd(III) complex, there are ferromagnetic Gd(III)-Rad interactions and antiferro-magnetic Rad-Rad interactions in the molecules (with J _(Rad-Gd) = 0.19 cm ~(-1), ~J _(Rad-Gd) = ~(-1).91 cm ~(-1)). And the analogous complex of [Tb(hfac) _3(NITPhOC _4H _9) _2] (2) shows the strong ferromagnetic Tb(III)-Rad interactions.