Four tri-spin lanthanide–nitronyl nitroxide (LnIII = GdIII, DyIII, ErIII, and HoIII) complexes: syntheses, structures, and magnetic properties

Abstract

Four radical–Ln(III)–radical complexes, [Ln(hfac)3(NITPhSCH3)2] (Ln = Gd (1), Dy (2), Er (3), Ho (4); hfac = hexafluoroacetylacetonate; NITPhSCH3 = 4′-thiomethylphenyl-4,4,5,5tetramethyl-imidazoline-1-oxyl-3-oxide), have been synthesized, and structurally and magnetically characterized. The X-ray crystal structures show that the structures of the four complexes are similar, consisting of isolated molecules in which Ln(III) ions are coordinated by six oxygen atoms from three hfac and two oxygen atoms from nitronyl radicals. The temperature dependencies of magnetic susceptibilities for the four complexes show that in the Gd(III) complex, ferromagnetic interactions between Gd(III)–radical and antiferromagnetic interactions between the radicals coexist with J Rad–Gd = 1.09 cm−1, J Rad–Rad = −1.85 cm−1.